ISSN 1020-3362 Plant Genetic Resources Newsletter Bulletin de Ressources Phytogénétiques Noticiario de Recursos Fitogenéticos No. 123, 2000 Food and Agriculture Organization of the United Nations and the International Plant Genetic Resources Institute Organisation des Nations Unies pour l'alimentation et l'agriculture et l'institut international des ressources phytogénétiques Organización de las Naciones Unidas para la Agricultura y la Alimentación y el Instituto Internacional de Recursos Fitogenéticos Bureau de rédaction Oficina de Redacción The designations employed, and the presentation of material in the periodical, and in maps which appear herein, do not imply the expression of any opinion whatsoever on the part of IPGRI or FAO concerning the legal status of any country, territory, city or area or its authorities, or concerning the delimitation of its frontiers or boundaries. Similarly, the views expressed are those of the authors and do not necessarily reflect the views of IPGRI or FAO. Les appellations employées dans cette publication et la présentation des données et cartes qui y figurent n’impliquent de la part de l’IPGRI et de la FAO aucune prise de position quant au statut juridique des pays, territoires, villes ou zones, ou de leurs autorités, ni quant au tracé de leurs frontières ou limites. Les opinions exprimées sont celles des auteurs et ne reflètent pas nécessairement celles de l’IPGRI ou de la FAO. Las denominaciones empleadas, y la forma en que aparecen presentados los datos en esta publicación, no implican, de parte del IPGRI o la FAO, juicio alguno sobre la condición jurídica de países, territorios, ciudades o zonas, o de sus autoridades, ni respecto de la delimitación de sus fronteras o límites. Asimismo, las opiniones expresadas son las de sus autores y no reflejan necesariamente la opinión del IPGRI o la FAO. Cover: Close-up of part of a wild cassava plant in the field. This crop is discussed in the paper by Allem (pp. 19-22). Photo by IPGRI. Couverture: Gros plan d'une plante sauvage de manioc sur le terrain. Cette culture est commentée dans le document de Allem (pp. 19-22). Photo IPGRI. Portada: Primer plano de una parte de la planta silvestre de mandioca en el campo. Se habla de este cultivo en el documento escrito por Allem (pp. 19-22). Foto del IPGRI. Editorial Office Managing Editor Plant Genetic Resources Newsletter IPGRI Via delle Sette Chiese 142 00145 Rome, Italy Tel.: +39-0651892233 Email: [email protected] Fax: +39-065750309 Web: http://www.ipgri.cgiar.org © IPGRI/FAO 2000 Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123: 1231- 1 8 ARTICLE Utilization of germplasm conserved in Chinese national genebanks – a survey Gao Weidong¹*, Jiahe Fang¹, Diansheng Zheng¹, Yu Li¹, Xinxiong Lu¹, Ramanatha V. Rao², Toby Hodgkin³ and Zhang Zongwen4 ¹ Institute of Crop Germplasm Resources of the Chinese Academy of Agricultural Sciences, Beijing 100081, China. Email: [email protected] ² IPGRI Regional Office for Asia, the Pacific and Oceania, Serdang, Malaysia ³ IPGRI, Rome, Italy 4 IPGRI Office for East Asia, Beijing, China Summary Résumé Resumen Utilization of germplasm conserved in Chinese national genebanks – a survey Enquête sur l’utilisation du matériel génétique conservé dans les banques de gènes nationales en Chine Estudio del uso de germoplasma conservado en bancos nacionales de China A survey on the use of germplasm conserved in Chinese national genebanks was conducted jointly by the Institute of Crop Germplasm Resources of the Chinese Academy of Agricultural Sciences (CAAS) and IPGRI in 1998-99. A study was made of the distribution of accessions in the 15-year period from 1984 to 1998, the 10 crops targeted being: rice, wheat, soyabean, maize, cotton, oranges, tea, mulberry, cabbage and cucumber. The aim was to determine patterns of germplasm distribution and use, identify constraints to the use of germplasm conserved in genebanks and suggest how the situation could be improved. This investigation was conducted through a literature review, a questionnaire, a workshop and site visits. The results showed that 178 495 accessions of the 10 target crops, including 448 species and 29 subspecies, have been collected in China, of which 161 979 accessions were preserved in seed genebanks and 16 516 accessions in field genebanks. Over the 15-year period, germplasm distributed by genebanks was used for screening crop germplasm resources (i.e. for characterization and evaluation for desired traits), for breeding, for basic research and for other uses (including direct use in production). Some accessions were not used by recipients but only stored as part of a working collection. The research identified 24 factors limiting the effective use of germplasm according to the respondents. For example, most thought that present policies and systems were not beneficial to the sharing of crop germplasm resources and that this has led to insufficient germplasm distribution and use. Recommendations were made to increase the use of germplasm in China. This research could also be considered a model for surveying the use of germplasm in other countries or genebanks. Key words: Cabbage, China, cotton, cucumber, genebanks, germplasm, maize, mulberry, oranges, rice, soyabean, tea, wheat Une enquête sur l’utilisation du matériel génétique conservé dans les banques de gènes nationales en Chine a été menée conjointement par l’Institut des ressources génétiques des plantes cultivées de l’Académie chinoise des sciences agronomiques et l’IPGRI en 1998-99. On a étudié la distribution des accessions sur une période de 15 ans (1984-1998), pour 10 cultures cibles: riz, blé, soja, maïs, coton, orange, thé, mûre, chou et concombre, afin de déterminer les modes de distribution et d’utilisation du matériel génétique, et d’identifier les obstacles à l’utilisation du matériel génétique conservé dans les banques de gènes et les possibilités d’amélioration de la situation. L’étude a consisté en une étude bibliographique, un questionnaire, un atelier et des visites de sites. Les résultats montrent que 178 495 accessions des 10 cultures cibles, comprenant 448 espèces et 29 sous-espèces, ont été collectées en Chine : 161 979 ont été conservées dans des banques de semences et 16 516 dans des collections au champ. Au cours de la période considérée, le matériel génétique distribué par les banques de gènes a été utilisé pour le criblage des ressources phytogénétiques (caractérisation et évaluation), la sélection, la recherche fondamentale, l’utilisation directe (culture), etc. Certaines accessions n’ont pas été utilisées par les bénéficiaires, mais conservées dans une collection de travail. L’enquête a permis d’identifier 24 facteurs qui, selon les personnes interrogées, limitent l’utilisation efficace du matériel génétique. La plupart estiment que les politiques et systèmes actuels ne favorisent pas le partage des ressources phytogénétiques, d’où une distribution et une utilisation insuffisantes de ce matériel. Des recommandations sont formulées pour le développement de l’utilisation du matériel génétique en Chine. Cette enquête pourrait servir de modèle à des études similaires dans d’autres pays ou d’autres banques de gènes. El Instituto de Recursos de Germoplasma Vegetal de la Academia China de Ciencias Agrícolas y el IPGRI estudiaron conjuntamente en 1998-99 el uso de germoplasma conservado en bancos de germoplasma nacionales de China. Se estudió la distribución de accesiones durante 15 años (1984- 1998), de 10 cultivos: arroz, trigo, soja, maíz, algodón, naranjas, té, mora, col y pepino. Se pretendía determinar pautas de distribución y uso de germoplasma, señalar las limitaciones en el uso del germoplasma conservado en los bancos y sugerir formas de mejorar la situación. La investigación se realizó a través de una revisión de la bibliografía, un cuestionario, una taller y visitas sobre el terreno. Se constató que se habían recogido en China 178 495 accesiones de las 10 plantas citadas, correspondientes a 448 especies y 29 subespecies, de las cuales 161 979 accesiones se conservaban en bancos de semillas y 16 516 accesiones en bancos en el campo. Durante los 15 años, el germoplasma distribuido por los bancos se utilizó para seleccionar recursos de germoplasma (o sea para caracterizar y evaluar rasgos deseados), para mejora genética, para investigación básica y para otros usos (como el uso directo en la producción). Los receptores no usaban todas las accesiones, sino que guardaban algunas como parte de una colección de trabajo. Se enumeraron 24 factores limitativos del uso efectivo del germoplasma según los encuestados. Por ejemplo, la mayoría pensaban que las políticas y sistemas actuales no favorecen el intercambio de recursos de germoplasma y que por ello son insuficientes su distribución y su uso. Se formularon recomendaciones para aumentar el uso de germoplasma en China. Este trabajo puede servir de modelo para estudiar el uso de germoplasma en otros países o bancos de germoplasma. 2 Plant Genetic Resources Newsletter, 2000, No. 123 Introduction Over the 15-year period under study, from 1984 to 1998, the central government in Beijing has established a modern longterm storage genebank, a duplicate genebank and a number of medium-term genebanks for germplasm exchange. In addition, 32 national germplasm nurseries for perennial and vegetatively propagated crops (including two in vitro banks), and 21 local and provincial medium-term genebanks have been established nationwide. These provide basic facilities for the conservation and research of crop genetic resources. By September 1998, the germplasm preserved in the national genebanks and nurseries had reached 355 000 accessions. Of these, 318 000 accessions of 161 crops, belonging to more than 600 species of 174 genera of 30 families, are preserved in the long-term genebank and over 37 000 accessions of more than 50 crops, belonging to 1026 species or subspecies, are preserved in the germplasm nurseries. Germplasm conserved in genebanks accounts for approximately 85% of accessions collected in China. Much of this is endemic to China and includes rare germplasm and wild relatives of crops, including elite material for crop improvement (Gao Weidong and Shumin Wang 1997). In the same period genebanks have also distributed hundreds of thousands of germplasm to institutions and researchers at home and abroad. However, the use being made of the distributed germplasm is unclear. There still seems to exist in China the belief that “crop germplasm resources are abundant but breeding materials are scarce”. Although some factors limiting the effective use of germplasm are known, little has been done to examine the extent of this or how to reduce the phenomenon. The present project aimed to explore the use of germplasm in China from 1984 to 1998 in order to collect information on germplasm utilization in agriculture, genetic research, character evaluation, germplasm enhancement and exploitation; provide a scientific basis for solving the problems mentioned above, and formulate strategies to increase the use of crop germplasm resources. Materials and methods Target crops The target crops include rice, wheat, soyabean, maize, cotton, citrus, tea, mulberry, Peking cabbage and cucumber. Information on the distribution, exchange and utilization of this germplasm, which is preserved in the national medium-term genebanks, nurseries and local genebanks, was collected for the 15-year period 1984 to 1998. Major activities Survey by questionnaire A total of 676 questionnaires were sent to experts in China (580) and abroad (96) at the beginning of January 1999. By the end of June 1999, 249 questionnaires (36.8%) had been returned. Approximately 41% of Chinese scientists responded and 11.5% of scientists from other countries (Table 1). Literature review More than 120 papers and other documents on germplasm utilization in China were reviewed, such as Chinese Agricul- tural Sciences, Acta Genetica Sinica, Acta Botanica Sinica, Acta Phytophysiologica Sinica, Acta Phytochemica Sinica, Acta Agronomica Sinica, Journal of Crops, Acta Entomologica Sinica, Crop Genetic Resources, Chinese Rice Sciences, Triticeae crops, Maize Sciences, Soybean Sciences, Fruit Sciences, Acta Horticulturae Sinica, Cotton in China, Citrus in China, Vegetables in China, Tea Sciences, Mulberry Sciences and other local journals. Workshop A workshop on the status of germplasm utilization, problems and solutions at the national genebanks/nurseries in China was held from 26 to 27 May 1999 and hosted by the Institute of Crop Germplasm Resources of Chinese Academy of Agricultural Sciences (CAAS). Twenty-one scientists from different institutions attended the workshop. Case studies Experts undertook on-the-spot investigations at 13 institutes: the Crop Cultivation and Breeding Institute, the Cotton Institute, the Citrus Institute, the Vegetable and Flower Institute, the Tea Institute, the Mulberry Institute and the Crop Germplasm Resources Institute all of CAAS; the China Rice Research Institute; the Jilin Academy of Agricultural Sciences; the Shanxi Academy of Agricultural Sciences; the Hainan Academy of Agricultural Sciences; the Northeast Agricultural University; and the Nanjing Agricultural University. The focus was on investigating the status of germplasm distribution and utilization for the 10 crops identified. Results and discussion Germplasm preservation A total of 178 495 accessions of the target 10 crops, consisting of 448 biological species and 29 subspecies, have been collected in China (Table 2). Of these, 161 979 accessions are preserved in genebanks and 16 516 accessions are preserved in nurseries. Germplasm distribution Given the information in the survey, it is evident that germplasm distribution for the 10 crops made great progress in 15-year period examined (Table 3). A total of 184 743 accessions were distributed to 8635 institutions concerned with crop breeding, basic research, production and teaching. The material distributed included bred varieties, breeding lines, landraces, wild relatives and genetic stock. The crops were rice, wheat, maize, soyabean, cotton, citrus, Peking cabbage, cucumber, tea tree and mulberry. Germplasm utilization The current project investigated the status of germplasm utilization for the 10 target crops (Table 4). It was shown that the use of germplasm could be divided into five areas: screening, breeding, basic research, other uses and no use made of the material. According to the survey, of the 136 802 accessions received in the 15-year period, 21% of the total were used for screening crop germplasm resources, 8.1% for breeding, 9.0% for basic research, 2.0% for other purposes and 59.9% were not used at all. Plant Genetic Resources Newsletter, 2000, No. 123 3 Table 1. General information concerning respondents Respondents from China Respondents from abroad Total Activity No. % No. % No. % Curator Breeder Curator and breeder Other Total 43 88 101 18.1 37.0 42.4 2 1 7 18.2 9.1 63.6 45 89 108 18.1 35.7 43.4 6 238 2.5 41.0 1 11 9.1 11.5 7 249 2.8 36.8 From Table 4 it can be seen that mainly cultivars were used for breeding, with the percentage of wild relatives used being considerably lower (0.4%), although their potential is noteworthy. Landraces and breeding lines were used mainly for screening useful characteristics and genetic stock was used mainly for basic research. Wild relatives were used for screening and basic research, and cultivars were mainly used for screening. Further information on the use of germplasm in breeding, production and basic research is given below. Table 2. Conservation status of 10 target crops in China Crop Rice Wheat Maize Soyabean Cotton Citrus Peking cabbage Cucumber Tea tree Mulberry Total Species 36 297 1 3 60 22 – 1 17 11 448 Subspecies 2 18 – – – – 1 – 5 3 29 Accessions conserved Genebank Nursery Total 64 390 41 013 15 967 31 206 6264 – 1665 1474 – – 161 979 73 323 42 811 15 967 31 206 6724 1041 1665 1474 2527 1757 178 495 8933 1798 – – 460 1041 – – 2527 1757 16 516 The use of germplasm in breeding The 13 breeding institutes that received accessions used 21.1% in crop improvement (Table 5). Altogether 1281 varieties were bred using 1487 accessions. Of the 1487 accessions, 0.8% were from genebanks and nurseries. This indicates that the rate of effective use was higher for cash crops than for field crops. The total area planted with varieties bred using germplasm received as parents has been estimated at 37 481 720 ha for the 15-year period. This is 25.2% of the total area planted with the target crops. Of the total area cultivated with germplasm received from genebanks or nurseries, 18 497 400 ha was planted with rice, 10 207 400 ha Table 3. The status of germplasm distribution by germplasm holders for 10 target crops (1984-98) Crop Landraces Advanced lines Genetic stocks Wild relatives Rice Wheat Maize Soyabean Cotton Citrus Peking cabbage Cucumber Tea Mulberry Total 8586 2517 800 8850 31 10 440 2500 2200 4500 1000 41 424 (22.4%) 26 700 23 566 1000 2500 4510 – 900 750 – 85 60 011 (32.5%) 450 1989 100 250 135 744 45 – 300 35 4048 (2.2%) 949 1508 10 1500 55 1417 – – 2175 50 7664 (4.1%) Cultivars Total (%) 21 065 23 430 3000 5000 10 269 7310 60 30 910 522 71 596 (38.8%) 57 750 (31.3) 53 010 (28.7) 4910 (2.7) 18 100 (9.8) 15 000 (8.1) 19 911(10.8) 3505 (1.9) 2980 (1.6) 7885 (4.3) 1692 (0.9) 184 743 Table 4. Information on the use of the germplasm received for the target crops (1984-98) Germplasm use Landraces Advanced lines Genetic stocks Wild relatives Cultivars Total Germplasm received Screening No. % Breeding No. % Basic research No. % Other (including No. direct use) % Not used No. % 40 701 9668 23.8 2390 5.9 3557 8.7 605 1.5 24 481 60.1 54 114 9562 17.6 4258 7.9 3028 5.6 1305 2.4 35 961 66.5 1 348 160 11.9 57 4.2 769 57.0 50 3.7 312 23.2 6729 634 9.4 27 0.4 638 9.5 35 0.5 5395 80.2 33 910 8731 25.8 4345 12.8 4286 12.6 712 2.1 15 836 46.7 136 802 28 755 21 11 077 8.1 12 278 9.0 2707 2.0 81 985 59.9 4 Plant Genetic Resources Newsletter, 2000, No. 123 Table 5. Utilization of germplasm received at the 13 main breeding centres (1984-98) Germplasm involved in development of released varieties Total area cultivated Germplasm used for breeding From genebanks Total Crop† ‘000 ha Germplasm received No. % Varieties bred No. % No. Rice Wheat Maize Soyabean Cotton Citrus Cucumber Tea Mulberry Total 18 497.67 10 207.40 6609.09 300.80 1789.29 2.54 66.90 4.11 3.92 37 481.72 35 000 53 010 4523 13 300 1662 700 1474 1772 398 11 1839 3260 13 252 733 4633 1170 138 400 34 30 23 650 9.3 25.0 16.2 34.8 70.4 19.7 27.1 1.92 7.5 21.1 376 267 120 292 192 8 64 109 19 1 447 303 213 87 36 163 11 32 34 13 892 0.87 0.4 1.92 0.27 9.8 1.57 2.17 1.92 3.27 0.8 393 1.12 424 0.8 141 3.1 71 5.3 282 16.9 17 2.43 106 7.19 34 1.92 20 5.03 1487 1.33 † % Peking cabbage was not included. with wheat, 6 609 090 ha with maize and 1 789 290 ha with varieties of cotton. Currently, 85% of the major crops in China are grown using modern varieties. This has resulted in annual rice yields rising from 5250 kg/ha in 1985 to 6319 kg/ha in 1997, wheat yields from 2490 kg/ha in 1985 to 4101 kg/ha in 1997, corn yields from 3600 kg/ha in 1985 to 4387 kg/ha in 1997, soyabean from 1365 kg/ha in 1985 to 1764 kg/ha in 1997 and cotton from 810 kg/ha in 1985 to 1024 kg/ha in 1997. In addition, approximately 7080% of maize is grown using maize hybrids. All of these achievements are closely dependent upon the use of crop germplasm. Xiaohongmai has been grown for its drought tolerance in the Inner Mongolian Region for at least 100 years and the rice landraces Zhubao and Yabao have been grown in Lingshui County of Hainan Province (where the Li ethnic group lives) for at least 30 years. The use of landraces has not only protected biodiversity but also helped to develop local economies. However, new varieties with high yields, good quality and resistance to diseases and pests have replaced landraces in most regions, although landraces are still used in some remote regions and areas where minor ethnic groups live. Prof. Manmao Qian (Qian et al. 1996) has estimated that in the 1950s nearly 10 000 wheat cultivars were still being used in China but that only 300 Direct use in production improved varieties are currently in use. The survey showed that in the 15-year period under discussion, The survey results showed that approximately 66 major rice 178 landraces were directly used in production on 12 722 000 ha, landraces, such as Laohudao and Hongkewan, are used in rice accounting for 0.9% of the cultivated area grown with the target production on 77.5% of the total area grown with landraces in crops (Table 6). In general, improved varieties of field crops have the 15-year period. For soyabean, 13 major landraces are still been in production for 3-7 years, tea trees and mulberry for 5-15 currently used in production including Shizhu Zhuyaozi of years and vegetables for 2-4 years. Landraces, however, have been Sichuan and Juhuang of Guangdong, with a growing area 8.3% in use for much longer. For example, the wheat landrace of the area grown with landraces. Other major landraces include Xiaohongmai for wheat on 7.8% of the area planted; Table 6. Use of landraces for the 10 target crops (1984-98) Baibaomi, Huobaomi and Huanghuoyumi for maize on 3.2% of the area planted; Husang 32, Dahuasang No. of and Dayibai for mulberry on 1.3% of the area landraces Growing planted; Yichuanling and Xintaimici for cucumber Crop used Elite traits used area (ha) on 1.0% of the area planted; 15 landraces such as Rice 66 Disease resistance 9 909 000 Qichen and Xuechen for citrus on 0.3% of the area Wheat 1 Stress tolerance 1 000 000 planted, and 50 landraces, such as Xuchuan Maize 10 Disease resistance, early 46 031 Gouniannaocha of Jiangxi and Tenchong maturity, drought tolerance Wenjiatangdayecha of Yunnan for tea on 0.1% of Soyabean 13 Large grain, used for 1 064 050 vegetables, early maturity the total area planted with landraces. No landraces Citrus 15 Good quality, high yield, 39 700 are used to grow cotton. Cucumber Tea Mulberry Total 4 50 19 178 early maturity Disease resistance, cold tolerance Good quality, high yield High yield 124 500 16 055 163 388 12 362 724 Basic research For the 10 target crops, 12 278 accessions were used for basic research (see Table 4). This has mainly focused on the following areas: genetics and the Plant Genetic Resources Newsletter, 2000, No. 123 5 mechanism of heterosis, botany, plant taxonomy, biological diversity, plant physiology, plant biochemistry, phytopathology and resistance mechanisms, molecular biology, genetic engineering, cytological engineering and environmental biology. Most of the research results were published in China. Limiting factors in the use of germplasm resources The use of crop germplasm resources in China has made great progress since 1984. However, there are some factors which limit its effective use (see Table 7). The survey investigated the views of respondents working in different areas of genetic resources. The questions can be divided into five categories: (a) characterization and evaluation (8-11), (b) exchange and communication (1, 2, 4, 14), (c) germplasm enhancement (13), (d) policies (1922) and (e) other factors. Respondents differed on numbers 3, 57, 12, 15-18, 23 and 24 which came under (e) and were in agreement on questions 1, 8-11, 13 and 19-22. Further details are given in Table 8. Germplasm characterization and evaluation The survey showed that there was a lack of in-depth studies on the huge collections and basically that germplasm was characterized and evaluated phenotypically, which led to an unclear understanding of its use value. For some accessions, no characterization and evaluation of agronomic characters, resistance to disease and pests or tolerance to stress had been carried out. For example, although all the wheat germplasm (38 000 accessions) preserved in the national genebanks had been characterized agronomically, resistance to seven diseases had been evaluated for only 22 000 accessions, drought tolerance for only 15 000 accessions, cold and salt tolerance for only 2000-3000 accessions, and crude protein and lysine content for only 20 000 accessions. Approximately two-thirds of maize germplasm had been characterized and evaluated for resistance to disease and pests, stress tolerance and quality analysis. This lack of characterization and evaluation has undoubtedly limited, to some extent, the wide use of the rich genetic diversity available and the enhancement of germplasm. Germplasm exchange and communication Medium-term germplasm exchange banks, facilities for germplasm multiplication and regeneration, and information networks are needed for the effective use of germplasm resources. For many reasons, however, these facilities have not been established or perfected. Most of the medium-term genebanks are located in different provinces and are responsible for the medium-term preservation of local germplasm. Some provinces have no modern medium-term genebanks and the conditions for preservation are poor. Approximately 7% of respondents have long-term genebanks, 20% medium-term banks, 42% germplasm nurseries, 29% working genebanks and 2% no genebanks. Moreover, because of the lack of funding for the regeneration of germplasm preserved in the medium-term banks, no material is available for distribution and some accessions have been lost. As some provincial medium-term genebanks are not linked to the National Germplasm Information Database, this has led to the ineffective germplasm and information exchange between units working on germplasm and units working on breeding and basic research. Thus, some germplasm curators are unaware of Table 7. Factors limiting the use of crop germplasm resources (CGR) No. Statement 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Limited exchange of CGR information Breeders do not know CGR information in genebanks Curators do not know breeders’ needs Poor distribution of CGR Insufficient number of CGR for target crop in genebanks Insufficient number of useful CGR for target crop in genebanks Little genetic diversity of target crop preserved in genebanks Insufficient characterization and evaluation in genebanks Insufficient characterization and evaluation for disease and pest resistance of CGR in genebanks Insufficient characterization and evaluation for stress tolerance (e.g. cold, drought, salt, etc.) of CGR in genebanks Insufficient genetic evaluation of CGR in genebanks Unreliable data of CGR characterization and evaluation Insufficient CGR enhancement Obtaining desirable CGR from national medium-term genebanks is difficult Amount of CGR supplied by national genebanks is not sufficient to meet needs Time taken to respond and provide CGR requested is very long Obtaining CGR from national medium-term genebanks is expensive Property right may be involved if CGR from other Chinese institutions is used Elite materials held by breeders is not preserved in genebanks Present policies and systems are not beneficial to CGR sharing Government has not paid great attention to genetic resource activities Breeders do not request CGR from curators Introduction of desirable materials from other countries is faster and less expensive than requesting them from Chinese institutes or enhancement by self Requests for CGR are sometimes limited by policies, e.g. only institutions that send CGR to the genebank can obtain the CGR 24 6 Plant Genetic Resources Newsletter, 2000, No. 123 breeders’ urgent requirements and breeders are unaware of the information available on germplasm. This has resulted in the inaccurate objectives of both curators and breeders. Germplasm enhancement Germplasm enhancement to broaden genetic diversity is very important for the effective use of germplasm resources. In China, poor germplasm enhancement and improvement has led to the poor exploitation and inefficient use of elite germplasm. With the exception of a few landraces, it is impossible that all germplasm traits are elite. In the past, breeders used traditional breeding methods to develop varieties and they often needed only one or two elite traits. Nowadays they require materials with more elite traits resulting in an urgent need for germplasm enhancement. Policies Firstly, although the Government has paid considerable attention to crop germplasm resources in the past two decades, not enough has been done to support such a huge undertaking and insufficient resources have been given to increasing public awareness. Secondly, in general the Government does not give high priority to germplasm management and this has led to the lack of funds and poor equipment in some genebanks. Thirdly, present policies do not facilitate sharing germplasm between holders and users, and the intellectual property rights of holders and breeders cannot be protected effectively. This is why some elite material owned by breeders is not preserved in the national genebanks and/or nurseries and, therefore, cannot be used by others. Other factors Respondents had different opinions on the following questions. (a) Do germplasm curators know the needs of breeders? (b) Are the accessions preserved in the genebanks sufficient for research? (c) Is there enough useful germplasm in the genebanks? (d) Is there sufficient genetic diversity in the accessions preserved in the genebanks? (e) Is the amount of seed provided enough? (f) Does the time for seed provision take too long? (g) Is the cost of obtaining germplasm from the genebanks too high? (h) Is the introduction of parents from abroad faster and quicker than waiting for germplasm enhancement by breeders? An analysis of the returned questionnaires is given in Table 8. Analysis of limiting factors involved in germplasm utilization The use of germplasm resources The survey supports the view that germplasm should be further evaluated to promote its utilization. Over 90% of respondents stated they would use germplasm for breeding purposes if it was evaluated more. Lack of funds is considered to be the most important limiting factor in the use of germplasm, followed by policy, evaluation, information and others. Germplasm sharing The survey showed that more than half the respondents proposed that the sharing of germplasm should conform to the principle of bilateral benefit, that is, breeders or others who hope to use the germplasm preserved in the genebanks may obtain materials required but at considerable cost. This is perhaps a Table 8. Analysis of factors limiting germplasm utilization Factor Response Germplasm received needs further evaluation Yes No Yes No Financial Policies Characterization and evaluation data Information Other Policies Lack of useful germplasm Lack of information Other Catalogues Journals Database systems Oral presentation Other Bilateral benefits Distribution free of charge Other No policy guarantee benefits No mutual understanding Low genetic diversity of germplasm in genebanks Belief that other breeders do not have elite germplasm Other Germplasm received is used in breeding programmes Major limiting factors in using germplasm Most serious problems in germplasm enhancement Major approaches to access information of germplasm Ways to share information and elite germplasm Major difficulties in germplasm exchange among breeders and curators China (%) Abroad (%) 90 8 98 2 45 31 14 9 1 34 27 19 20 34 36 7 20 3 79 18 3 55 29 8 80 20 80 20 33 33 17 17 0 37 13 25 25 33 22 28 17 0 50 40 10 33.3 33.3 11.1 2 11.1 6 11.1 Plant Genetic Resources Newsletter, 2000, No. 123 7 good way for developing countries, such as China, to sustainably run genebanks and nurseries, and provide materials to breeders and other users. However, the measures taken should be in keeping with the requirements of the International Undertaking on Plant Genetic Resources. Germplasm enhancement According to the respondents, the major limiting factors for germplasm enhancement are policies, the lack of useful germplasm and the shortage of information. Policies are the main bottleneck but determining which materials should be enhanced is also critical. Germplasm and information exchange The difficulties in germplasm and information exchange mainly result from the lack of protection of intellectual property rights and the lack of communication between breeders and curators. Breeders and other germplasm users obtain information concerning germplasm mainly via catalogues and journals. However, scientists in other countries also obtain information via information databases. Some Chinese scientists are now beginning to use these methods. Suggestions and recommendations During this study, experts from different fields made many suggestions on how to effectively improve the use of germplasm. After careful analysis of these suggestions, the following list of proposals has been drawn up. 1. Strengthening characterization, evaluation and the enhancement of germplasm While germplasm collecting and preservation should continue, in the near future the emphasis should be shifted to characterization and evaluation, and in-depth research into germplasm resources. Biotechnology, including the use of molecular markers, cell engineering and genetic engineering, should be used in germplasm enhancement and more genotyping should be conducted. In particular, favourable genes existing in wild relatives of crops should be transferred to cultivars to obtain new types of germplasm. Germplasm researchers should provide not only elite germplasm but also information concerning its characteristics and genetic mechanism in order to improve the use of the material. Germplasm enhancement should target diverse ecological regions and diverse breeding objectives. For wild relatives especially, more trials and research is needed in order to exploit potential value. Germplasm researchers should understand the unique advantages and the accompanying disadvantages of their own accessions, and then form clear objectives to improve them. 2. Promoting the exchange of germplasm and associated information Approximately 350 000 accessions are preserved in the National Genebank of China and in medium-term genebanks. However, the limited multiplication of accessions in China seriously influences the distribution and exchange of germplasm resources. It is suggested that germplasm researchers should increase and improve their contacts with breeders to exchange germplasm and associated information. To do this, various activities need to be organized such as ecogeographical trials. These should include material from different ecological regions and provide opportunities for interaction between germplasm researchers and users as well as farmers. A national information network, accessible to breeders and other researchers, should also be developed to provide relevant information on germplasm conservation, characterization, evaluation and enhancement. 3. Formulating benefit-sharing policies Benefit-sharing policies for the use of germplasm should be drawn up in order to encourage cooperation between germplasm holders and users. On the one hand, this should include the principle that germplasm providers should benefit from the use of their germplasm by breeders and other researchers, while on other, encourage breeders to send their improved and enhanced elite materials to genebanks for preservation, exchange and use. Paid germplasm services could be considered as a way of satisfying users and meeting the needs of the market. 4. Strengthening financial support The Government should increase its support for the conservation and use of germplasm resources. This is critical for promoting the various activities needed to increase the use of germplasm. At the same time, each institution concerned with germplasm should apply for funds, through the various channels available, to carry out research to identify, evaluate, enhance and ensure the provision of useful germplasm for crop improvement and other purposes. 5. Establishing a national coordinating mechanism A national coordinating mechanism is essential for the promotion of the use of plant genetic resources in China and a national committee for plant genetic resources should be the coordinating and decision-making body in the country, composed of officials from various sectors, as well as experts on conservation and the use of plant genetic resources. This body would be responsible for formulating rules and management policies, and for making short- medium- and long-term plans for action. 6. Future work It is suggested that the proceedings of the workshop organized for this project be published. This provides useful information on the use of crop genetic resources, particularly for the 10 target crops, and will assist scientists and the relevant authorities to make the decisions needed to strengthen the national programme for the conservation and use of crop germplasm in China. 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Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 9 - 18 9 ARTICLE The use of home gardens as a component of the national strategy for the in situ conservation of plant genetic resources in Cuba L. Castiñeiras1*, Z. Fundora Mayor1, S. Pico1 and E. Salinas2 Instituto de Investigaciones Fundamentales en Agricultura Tropical “Alejandro de Humboldt” (INIFAT), Calle 2 esqu. 1, Santiago de las Vegas, Ciudad de La Habana, Cuba. Tel: +53 7 579308; Fax: +53 7 579014; Email: [email protected] 2 Facultad de Geografía de la Universidad de La Habana, Calle 23 esqu. a L. Vedado Plaza, Ciudad de La Habana, Cuba 1 Summary The use of home gardens as a component of the national strategy for the in situ conservation of plant genetic resources in Cuba This study determines and describes the factors to be considered when developing a plan for the use of home gardens (“conucos”) as part of the in situ conservation of Cuban cultivated plant genetic resources. These factors were geographical, environmental, cultural, ethnological, phytogenetic, socioeconomic and type of agricultural production system, whether private or cooperative. On the basis of these and the diversity found in the “conucos” of the various provinces, 30 areas with different characteristics were selected from 12 provinces and the special municipality of Isla de la Juventud. The study also included the monitoring of some species for infraspecific variability, selected on the basis of their importance, origin and domestication in the Central American and Caribbean regions. On the basis of this study it is proposed to use home gardens to conserve plant genetic diversity and to integrate them into the existing ex situ (genebanks and botanical gardens) and in situ (protected areas) conservation programmes, as well as with socioeconomic programmes. The questionnaire used to select and monitor the “conucos” is given as an appendix. Key words: Ethnology, ex situ, home gardens, in situ, socioeconomics Résumé Utilisation des jardins familiaux comme composante de la stratégie nationale pour la conservation in situ des ressources phytogénétiques à Cuba Cette étude détermine et décrit les facteurs à prendre en compte lorsqu’on élabore un plan pour l’utilisation des jardins familiaux (“conucos”) dans le cadre de la conservation in situ des ressources génétiques des plantes cultivées à Cuba. Il s’agit de facteurs géographiques, environnementaux, culturels, ethnologiques, phytogénétiques, socioéconomiques et relatifs aux types de systèmes de production agricole, qu’ils soient privés ou coopératifs. Sur la base de ces facteurs et de la diversité présente dans les “conucos” des diverses provinces, 30 zones présentant des caractéristiques différentes ont été sélectionnées dans 12 provinces et la municipalité spéciale de Isla de la Juventud. L’étude comprend également le suivi de plusieurs espèces pour leur variabilité infraspécifique, choisies en fonction de leur importance, de leur origine et de leur domestication dans les régions d’Amérique centrale et des Caraïbes. Sur la base de cette étude, il est proposé d’utiliser les jardins familiaux pour conserver la diversité génétique des végétaux et de les intégrer dans les programmes de conservation ex situ (banques de gènes et jardins botaniques) et in situ (zones protégées) en cours, ainsi que dans des programmes socioéconomiques. Le questionnaire utilisé pour le choix et le suivi des “conucos” figure en annexe. Resumen Los huertos familiares como parte de la estrategia nacional para la conservación in situ de los recursos fitogenéticos en Cuba Este estudio enumera y describe los factores que hay que considerar para planificar el uso de los huertos familiares (“conucos”) con miras a la conservación in situ de los recursos genéticos de plantas cultivadas cubanas. Tales factores son geográficos, ambientales, culturales, etnológicos, fitogenéticos, socioeconómicos y relativos al sistema de producción agrícola, privada o en cooperativa. Sobre esta base y en función de la diversidad de “conucos” de varias provincias, se seleccionaron 30 zonas con características diferentes en 12 provincias y en el municipio especial de Isla de la Juventud. Se observó también la variabilidad intraespecífica de algunas especies seleccionadas por su importancia, su origen y su domesticación en América Central y el Caribe. Sobre la base de este estudio se propone utilizar los huertos familiares para conservar la diversidad fitogenética e integrarlos en los actuales programas de conservación ex situ (bancos de germoplasma y jardines botánicos) e in situ (zones protegidos), así como en los programas socioeconómicos. En el apéndice puede verse el cuestionario utilizado para seleccionar y observar los “conucos”. Introduction Cuba has a rich natural flora with approximately 6700 species of vascular plants distributed in 1300 genera and 181 families. Nearly 50% of the flora is endemic, one of the highest percentages in the Antillean area (Capote et al. 1992). Many authors have commented on the importance of home gardens for the in situ conservation of plant genetic resources. Altieri and Merrick (1987) and Altieri et al. (1987) discussed the role of in situ conservation in preserving traditional agricultural systems and Niñez (1986) pointed out that home gardens are a useful mechanism for conserving non-crop species and that, depending upon the diversity present, they can be considered as genebanks for primitive cultivars with a potential value. Ragione and Perrino (1995) have described a successful example of on-farm conservation of old fruit tree varieties in the Timber Valley, Italy, carried out for a number of years by several groups composed of farmers, local cooperatives and/or regional associations, farmer’s associations, local and regional institutions, amateur clubs and private nurseries. Salazar (1996) also discussed the important role of home gardens in rural communities for the conservation of rice in Viet Nam. Nevertheless, it is important to note that because of the small size of plant populations involved in home gardens, there is a risk of gene loss through genetic drift and founder effect. 10 Plant Genetic Resources Newsletter, 2000, No. 123 As Esquivel and Hammer (1994) pointed out, the in situ conservation of landraces and their wild relatives through the use of “conucos” in Cuba is important because it allows for the continuous process of evolution by means of introgression, domestication and adaptation to unfavourable conditions to take place in the natural environment. This has given rise to an interesting variability of cultivated plants in Cuba. These authors also stressed the importance of “conucos” as a refuge for landraces and obsolete cultivars, which are rich reservoirs of genes for adaptation and resistance. “Conucos” are small gardens where farmers practise traditional agriculture mainly based on local cultivars. They are also referred to as “vega”, “sitio” or “patio”, depending on their size and the locality in which they occur. A number of studies have been carried out on the historical development, structure and composition of Cuban “conucos” (Esquivel and Hammer 1988, 1992a, b). In some cases mixed gardens overspill into tropical forests making it difficult to identify the borders between them. The authors observed a total of 80 taxa in the six “conucos” studied and these were classified according to their use. Activities concerning plant genetic resources are supported by the State through the National System of Plant Genetic Resources (NSPGR), which is composed of a network of genebanks belonging to different institutions and ministries throughout the country where ex situ collections of the most important crops are preserved. These include, among others, sugar cane, tobacco, vegetables, grains, oil seeds, major tropical roots and tubers, bananas and plantains, citrus and fruit crops. The National System of Protected Areas, which are identified and managed according to the regulations of the World Conservation Union , is also integrated into the NSPGR. Home gardens are integrated with the protected areas used to preserve primitive and obsolete cultivated species. It is proposed to integrate these with the ex situ conservation strategies already existing in Cuba. According to Hodgkin (1995) there are two main considerations that need to be taken into account when considering the in situ conservation of plant genetic resources of cultivated plants: (a) the factors influencing farmers’ decisions to maintain diversity in their crops and (b) the approaches that could support farmers in maintaining diversity. The objectives of this study are: (a) to identify and describe the factors to be considered in developing a plan to use “conucos” as part of Cuba’s in situ conservation strategy, (b) to determine potential areas where “conucos” can contribute to the in situ preservation of the genetic resources of cultivated plants, on the basis of geographical, ethnological, phytogenetical and socioeconomic factors, and (c) analyze the possibility of creating a network of areas of in situ conservation using “conucos” to complement the already existing ex situ conservation programmes. vation of plant diversity were also examined, taking into consideration the different cultures that converge in Cuba (Rivero de la Calle 1966; Franco 1975; Ortiz 1975; Pérez de la Riva 1977; Valdés 1978, 1986; Dacal and Rivero de la Calle 1986). Wild and cultivated plants were analyzed and a survey undertaken of their origins and use in accordance with the scientific studies performed by Esquivel et al. (1989), Capote et al. (1992), Hammer et al. (1992), Knüpffer (1992), Rodríguez et al. (1992), and on previous collecting missions carried out in Cuba. In addition, socioeconomic factors affecting the Cuban agricultural system and types of land tenancy were studied to examine the importance that each gives to subsistence agriculture (MINAG 1991; Santana 1991). Materials and methods Results Secondary data used Major geographical factors were examined according to Salinas and Salinas (1992), and the types of Cuban landscape and their human modification over time were also analyzed to understand their effect on biodiversity (Perera 1986; Perera and Rosabal 1986; Leiva 1992). Ethnological factors that could influence the preser- The factors that need to be considered for the in situ conservation of cultivated plant genetic resources are given below. Analysis of secondary data Considering the data obtained on the main types of landscapes and the ethnological, phytogenetical and socioeconomic factors, 11 provinces were identified where “conucos” could be used for the in situ conservation of cultivated plants. In each area two to three families were visited. In some cases, once the purpose of the research had been explained, sites were recommended by members of the provincial delegations from the Ministry of Agriculture or by local experts As they knew the areas, including the crops grown, the production systems and the farmers, they were able to judge their suitability. In other cases they were selected at random by observing possible sites from the road. In order to prepare the exploration of the selected areas and to identify potential “conucos”, the mission examined information accumulated during previous visits and collecting missions, as well as the detailed studies of “conucos” carried out during the INIFAT-ZIGuK collaboration that took place between 1986-1993 (Esquivel and Hammer 1988; Esquivel et al. 1990, Esquivel and Hammer 1992a, 1992b; Hammer et al. 1992; Esquivel and Hammer 1994). Exploration missions A questionnaire was prepared to provide the data needed to select “conucos”. This included an introduction, general questions, data on the locality, ethnological data, data on the “conuco” (origin, area, destination of the production and its possible use) and specific information about the plants grown. This served as a guide for the exchange of information with the farmers and is given in Appendix 1. An inventory was made of cultivated plants present in the “conucos” to select possible species that merit conservation and to monitor variability. The study of infraspecific variability was based on visual observations of flower and fruit characteristics using IPGRI descriptors. In some cases infraspecific variability was obtained from interviews with farmers. Geography There are three main geographical features in Cuba: insularity (predominance of coastal landscapes and a strong marine influ- Plant Genetic Resources Newsletter, 2000, No. 123 11 ence on natural elements); geological and geomorphological complexity (the association of reliefs, plains and mountains, and the combination of the different types of relief); and climate (significant influence of winds and great variation in humidity associated with a very complex rain regime). Prior to 1492 when Cuba was ‘discovered’ by Christopher Columbus the inhabitants had made localized modifications to the landscape through hunting, fishing and agricultural activities. From the first half of the 16th century up to the 19th century rapid agricultural development took place, particularly with the growth of sugar cane plantations, the exploitation of forests and cattle raising. The third period, from the middle of the 20th century onwards, was characterized by a rapid loss of forests; an increase in relatively small farms growing sugar, plantain and citrus; the development of hunting; and an increase in urban areas (Leiva 1992). In 1963 national reserves were created, covering a total land area of 25 000 ha, in order to provide different levels of protection as recommended by the World Conservation Union (Leiva 1992, McNeely 1995) and to preserve the landscape. At present these comprise an estimated 9% of the land in Cuba. Ethnology Cuba’s population is of varied origin and is a mixture not only of races but also of cultures, with influences from Indoamerica, Europe, Africa, French Haiti and Asia as well as post-war immigrants from various countries. A short description of each ethnic group follows. Indoamericans The Taínos, of the Arawak tribes in the Orinoco area of South America, were the most advanced group of early settlers. During the conquest and colonization of Cuba, the aboriginal population diminished and indigenous people from Central America and the Caribbean, such as Yucatánecans, were brought in. Agricultural practices such as “tumba y quema” (slash and burn) for the cultivation of grains and maize, and “montones” (hills) for roots and tubers are examples of the influence of the indigenous cultures of Central and South America. Europeans The majority of immigrants were Spanish and they brought their Mediterranean implements and customs with them. English people living in Havana also had some cultural influence. Africans The most important factor in the introduction of African slaves was the development of the sugar cane industry at the end of 16th century (Pérez de la Riva 1977). African culture has been one of the strongest influences on Cuban culture, which can still be seen in the music, dance and religion. French-Haitians French influence was considerable, particularly in the eastern provinces where French immigrants built mansions near their coffee plantations. Many African slaves came to Cuba with their French masters from Haiti, and their descendants and some elements of their culture still survive. Asians After 1842 a great number of Chinese came to Cuba from the English colonies of Barbados, Jamaica and Trinidad. Later they were contracted directly from China to work in the agricultural sector and with them a new form of slavery commenced consisting of heavy workloads for extremely low rewards. The Japanese were a minority within the Asian immigrants and were concentrated in relatively few areas. Their most important role was in the development of fruit and vegetable crops. Post-war minorities After the Second World War many European immigrants came to Cuba, one group being the Swiss who settled in specific areas and introduced advanced agricultural technologies. In the first half of the 20th century many North Americans also settled in Cuba and their influence can still be seen in some food, cultural and linguistic customs. Phytogenetic According to Rodríguez et al. (1994), there are 809 endemic taxa of wild flora, belonging to 55 families and 86 genera, related to the cultivated plants in Cuba. One of the characteristics of this flora is the presence of species complexes (a group of similar related species), one example being Eugenia. The relative abundance of such complexes is an indication of genetic plasticity and suggests an active geneflow among them. Species related to cultivated rice, such as Oryza perennis, or to sweet potato (Ipomoea spp.), are other examples of this, as is the existence of an endemic fruit-bearing species of Solanum, which could be useful for breeding purposes. Knüpffer (1992) estimated that there are a total of 1045 taxa of cultivated flora belonging to 117 families and 531 genera, excluding woody trees and ornamental plants. The majority of these species are cultivated as medicinal plants (432), fruit crops (262), forage plants (173) or vegetables (99). These plants come mainly from America but also from Europe, Indochina, Indonesia, Africa and the Indian subcontinent. Socioeconomic There are three basic agricultural production systems in Cuba: (1) state production (state farms); (2) the cooperative sector, including cooperatives that provide credit and services (CCS), cooperatives for agriculture and cattle production (CPA), and basic units of cooperative production (UBPC); and (3) the private sector. Agricultural production in home gardens in the CPAs and UBPCs is dedicated to complementing food supplies as staple foods are obtained directly from the state sector and through internal trade networks. Crops grown in CCSs and in private farms are exclusively the property of the farmers who own the land and many families depend upon their produce. Farmers cultivate species and varieties that are then passed on from one generation to another, sometimes over periods of more than 80 years. In general, as they are adapted to poor agroclimatic conditions, these genotypes can be cultivated out of the main growing season and on the poorest farmland. Land use in extensive agricultural production systems may be determined by only one crop; in such cases home gardens occupy a very small area, poorly managed, and in general on the edges of land. Home gardens used for vegetables, and root and tuber production in the cooperatives are on better land than those in the extensive systems and occupy larger areas, although they are limited in size by an agreement with the cooperative. In urban areas, home gardens are managed by families who then share the produce. They may be located in peri-urban centres and sometimes include cultivation without soil (hydroponics). 12 Plant Genetic Resources Newsletter, 2000, No. 123 Plant genetic diversity in home gardens: proposed areas for in situ conservation The results of the exploration mission showed that it was possible to find a large variety of cultivated plants, as well as related wild species, in a number of different areas. Thirty localities with different characteristics from 12 provinces were selected. Two provinces were excluded due to their similarity with other selected areas close by. Table 1 gives the areas selected, some of their characteristics, the type of predominant landscape and the number of important species observed in each. Variability among the selected areas can be observed between the regions where there is a certain amount of agricultural development and those where isolation permits the maintenance of traditional or underutilized cultivars. Such areas are to be found throughout the country and among all the principal landscapes. Some “conucos” can be considered as living genebanks because of the variety of species maintained and the variability within them. These should be preserved for the future as a complement to ex situ strategies. The list of the principal species observed in the “conucos” is shown in Table 2. Species were classified into six groups according to their utilization by farmers. The group of roots and tubers included 16 species, legumes and grains 15 species, while 29 species could be classified as vegetables. A further 20 species were classified as fruit crops, 20 as medicinal, stimulants and spices, and seven species were placed in the group of fibres and ornamental plants. An analysis of the main crops in the areas visited enabled the identification of 107 species maintained by farmers in their own gardens. The variation within the home gardens visited indicates their potential for the conservation of plant genetic diversity. A high level of infraspecific variability was observed in many crops, based on morphological characters. For example, Phaseolus vulgaris possessed wide variation for seed characters and different degrees of resistance or tolerance to diseases in open conditions. Variability was even greater in Phaseolus lunatus, a species that is maintained as a perennial crop close to fences or in abandoned maize fields and given little or no attention. Another interesting case was that of maize where pure races such as ‘Criollo’, ‘Canilla’ and ‘Tuzón’ were only found in very isolated “conucos”. In the eastern region of Cuba it was also possible to find primitive cultivars of flint maize with little introgression from modern dent maize. High infraspecific variability was also observed in vegetables, such as in primitive cultivars of Lycopersicon esculentum and in a related weedy form L. esculentum var. cerasiforme. We observed variable populations of Capsicum annuum, C. chinense and C. frutescens dispersed throughout the island and it was interesting to note the high degree of cross pollination and morphological similarities among some of these species, which made identification difficult (Barrios 1999). It is common to find many species of fruit crops in “conucos” as they provide food as well as shade for houses, crops, pasture and roads. Infraspecific variability was considerable for roots and tubers. For example, Manihot esculenta was observed in the majority of the “conucos” visited, the primitive cultivars had a wide variation in texture, colour and root fibre. Primitive and variable cultivars of Ipomoea batatas, with wild related taxa, were also found throughout Cuba (Fernández et al. 2000). To summarize, crops such as bananas, plantains and common beans, with a range of species and types, appeared in most of the “conucos”. Other crops such as maize and sweet potato were also found, however, the most important vegetable crops grown were tomatoes, pumpkins and the Alliaceae, as these are extensively used in Cuban cooking. Medicinal plants have increased in importance in recent years and are given special care by families. In all probability this phenomenon is influenced by current socioeconomic factors, which have led to a scarcity of medicines. Doctors play an important role in promoting the use of plants for medicinal purposes. Survey to characterize and monitor “conucos” The utilization of farmers as local experts is important in the areas explored. Many farmers have lived in the same place sometimes for more than sixty years and know the farms as well as their home gardens, including the crops grown and their characteristics. The meetings with local experts, that took place prior to exploring a region, proved very useful for this study. Frequently farmers were recommended by the provincial delegations of the Ministry of Agriculture. In general, Cuban farmers are kind and hospitable. When arriving at a farmer’s home, the specialist described the Institution and the objectives of the research. During the discussions and while completing the questionnaire, members of the families gave interesting and useful answers. The recommendations and information given served as an introduction to other farmers allowing the whole region to be explored. Despite the current trend of migration from the country to the cities (temporally or definitively), farmers tend to maintain themselves on their land for more than sixty years. This is one reason why a home garden can be used for the in situ conservation of plant genetic resources. The educational and vocational level of family members, which were noted in the questionnaire, should be taken into consideration as they can have a positive or negative influence on the garden with respect to the diversity maintained and its utilization. This information is also useful for predicting the future of a “conuco”. Data on a family’s ethnic roots and the economic position of the owner are also significant as these factors are reflected in the choice of plants cultivated. Some questions dealt with quantitative indices like garden size, climatic characteristics and degree of pollution, while others were concerned with the organization of the garden. The replies provided information on the structure, composition and function of the garden. In many cases, “conucos” with similar plant taxa, content and organization were managed by their owners in completely different ways. A large number of questions were asked about the plants present in each “conuco” (Appendix 1-IV) in order to record each species and obtain information on the types and varieties of species present, and their relationship with wild or semi-wild types. The final question asked was whether the farmer would allow their “conuco” to be considered as a potential site for the in situ conservation of the plants. In the majority of the cases the answer was in the affirmative. Plant Genetic Resources Newsletter, 2000, No. 123 13 Table 1. Characteristics of the selected areas in different Cuban provinces, predominant landscapes and the number of species observed in each area Area Province Characteristics Predominant landscape frequently Guane Pinar del Rio Fluvial marine plains 15 Viñales Pinar del Rio Pinar del Rio Cocodrilo Isla de la Juventud† Karstic mountains and valleys Dissectional low mountains Karstic plains 20 Soroa Influence of Spaniards, tobacco cultivation Influence of Africans, tobacco cultivation in the valleys, timber French influence, timber, tourism Jucaro Isla de la Juventud† 11 Guira de Melena Havana Sandy accumulative alluvial plains Karstic plains Loma de Grillo Havana Highlands and hills 13 Stgo. de las Vegas Havana City Karstic plains 20 Alamar Cienaga de Zapata Havana City Matanzas Marine plains Accumulative marshy plains 11 13 Valle de Yumuri Matanzas Fluvial plains 12 Perico Matanzas Karstic plains 19 Highlands and hills denuded 16 Karstic dissectional low mountains 13 Low mountains denuded karstic Denuded and eroded plains Karstic plains 15 Moist highlands, hills and mountains 14 Sandy accumulative alluvial plains Denuded eroded plains Highlands and hills denuded karstic Low mountains denuded 16 Very moist middle mountains Highlands and hills denuded 14 15 Accumulative alluvial plains Low denuded mountains 14 15 Dissectional low mountains 15 Low denuded mountains 14 Accumulative eroded plains 16 Accumulative eroded plains 8 La Sierrita-San Blas Cienfuegos Topes de Collantes Sti. Spiritus Banao Sti. Spiritus Zaza del Medio Sti. Spiritus Cevallos Ciego de Avila Palma City – Sierra Cubitas Camaguey Omaja Las Tunas Velazco Yaguajay Holguin Holguin Pinares de Mayari Holguin Turquino Gran Piedra Santiago de Cuba Santiago de Cuba Guantanamo Valley Yateras Guantanamo Guantanamo Caujeri Guantanamo Yunque de Baracoa Guantanamo Cajobabo Guantanamo La Maquina Guantanamo † Havana Special Municipality Ethnic (caimaneros), fishing settlements in great isolation Strongly influenced by ethnic minorities (Japanese, North Americans) Intense agricultural development, still small farms, traditional crops and high-yielding cultivars Influence of ethnic minorities (Yucatecan Indians), relative isolation Relationship with foreign institutions, rich in fruit gardens with unique collections Urban area in peripheral zone Subsistence “conucos”, isolation, national park, potential ecotourism for rare-bird watching Isolation, ecotourism and health tourism development African and Asiatic influence, sugar cane dominates commercial production Coffee plantations, integrated programme for medicinal plants, potential for ecotourism Coffee and timber production, plant introduction or acclimatization, health and ecotourism Area of small vegetable farms Influence of ethnic minorities especially from Canary Islands Influence of ethnic minorities (North Americans), production of citrus fruit and vegetables Influence ethnic minorities (North Americans), cultivation of citrus and other fruits Influence of ethnic minorities (North Americans, Europeans) Agricultural development An important place for Taíno development. Obsolete cultivars Highly microclimatic, potential for ecotourism Isolated region, national park “Conucos” with rare and obsolete cultivars High temperature and salinity Isolation, occupied mainly by descendants of aboriginal groups Horticultural zone., “conucos” frequently feature obsolete and rare cultivars Isolated, coffee, coconut and cacao cultivation Isolated, agro-forestry systems and potential for ecotourism Coffee cultivation, some “conucos” contain obsolete cultivars No. of species 12 15 20 13 16 18 15 12 14 Plant Genetic Resources Newsletter, 2000, No. 123 Table 2. Main species found in Cuban “conucos” according to farmer’s utilization, their origin and the frequency of the species observed in the 30 sites selected Use/Species Roots/tubers Arracacia xanthorriza Beta vulgaris Brassica napus subsp. napus Brassica rapa Colocasia esculenta Cyperus esculentus Daucus carota Dioscorea alata Dioscorea bulbifera Ipomoea batatas Manihot esculenta Maranta arundinacea Plectranthus amboinicus Raphanus sativus Sechium edule Xanthosoma sagittifolium Origin Freq. NW† 1 OW OW 1 1 OW OW OW OW OW OW NW NW NW 2 3 2 1 3 2 10 8 3 OW 1 OW NW 1 4 NW 7 Grain/legumes Arachis hypogaea NW 8 Cajanus cajan Canavalia gladiata Canavalia spp. OW OW OW 5 1 1 Cicer arietinum Helianthus annuus Lablab purpureus Mucuna pruriens subsp. deeringiana Pachyrhizus erosus Panicum miliaceum Phaseolus lunatus Phaseolus vulgaris Sorghum vulgare Vigna ungiculata Zea mays OW NW OW OW 2 5 2 3 NW OW NW NW OW OW NW 1 2 13 12 2 13 11 Use/Species Origin Freq Medicinal/stimulant/spices Aloe vera OW 3 Use/Species Origin Freq. Fruits/fruit trees Averrhoa carambola OW 1 Aloe spp. Artemisia abrotanum Coffea arabica Coriandrum sativum Datura candida Erygium foetidum Laurus nobilis Mentha spicata Mentha spp. Nicotiana tabacum Ocimum basilicum OW OW 1 1 Annona reticulata Annona muricata NW NW 1 1 OW OW NW NW OW OW OW NW OW 2 4 1 1 3 4 1 3 2 Annona squamosa Carica papaya Citrullus lanatus Citrus aurantiifolia Citrus aurantium Citrus sinensis Cocos nucifera Cucumis melo Mammea americana NW NW OW OW OW OW OW OW NW 1 4 4 4 2 1 1 4 4 Ocimum gratissimun Ocimum temiflorum Orthosiphon aristatus Petroselium crispum OW 5 Manilkara zapota NW 2 OW OW 2 3 BO§ NW 4 1 OW 2 Mangifera indica Melothria guadalupensis Muntigia calabura NW 1 Saccharum officinarum Satureja hortensis OW 1 Musa spp. OW 9 OW 1 NW 2 Sesamum orientale Zingiber officinale OW OW 5 2 Pasiflora quadrangularis Persea americana Psidium guajabita NW NW 4 2 OW 6 Fibre/ornamentals Catharanthus roseus OW 2 NW OW OW 4 4 1 Gossypium hirsutum Gossypium spp. Justicia pectoralis NW NW NW 1 1 5 OW OW OW OW 3 1 8 9 Lippia alba Luffa acutangula Ruta chalepensis NW OW OW 4 1 1 NW OW OW OW OW OW OW 1 1 1 3 3 1 1 OW NW NW NW OW OW OW NW OW BO NW 1 2 2 5 1 1 4 12 1 1 10 OW OW NW 1 1 1 Vegetables Abelmoschus esculentus Allium canadese Allium cepa Allium cepa var. aggregatum Allium chinense Allium fistulosum Allium sativum Allium spp. Amaranthus spp. Apium graveolens Basella alba Benincasa hispida Brassica juncea Brassica napus Brassica napus var. esculenta Brassica spp. Capsicum annuum Capsicum chinense Capsicum frutescens Cimbopogon citratus Cucumis dipsacus Cucumis sativus Cucurbita moschata Lactuca sativa Lagenaria siceraria Lycopersicon esculentum Momordica charantia Solanum melongena Solanum ciliatum NW = New World; OW = New World; BW = both New and Old World. Plant Genetic Resources Newsletter, 2000, No. 123 15 Identification of crops to characterize and monitor the infraspecific diversity within and among the “conucos” It is important to identify the species and varieties that should be targeted for in situ conservation. As a considerable number of cultivated plant species posses high infraspecific variability, at least on the basis of the morphological characteristics observed, it was difficult to select crops for the characterization and monitoring of variability among home gardens for use in the next stage of the project. When selecting crops of primary concern for further studies, the origin and diversity of the species, in relation to their geographic position, were taken into account as well as ethnological and socioeconomic factors, the diversity found in previous exploration missions, the frequency of their appearance in the “conucos” visited, the type of crops and their utilization by farmers (Table 2). Using these criteria the following crops were selected: tomato (Lycopersicon esculentum), maize (Zea mays), peanut (Arachis hypogaea), pumpkin (Cucurbita moschata), common bean (Phaseolus vulgaris), lima bean (Phaseolus lunatus), origanum (Ocimum gratissimum), sweet potato (Ipomoea batatas), banana and plantains (Musa spp.), and cowpea (Vigna unguiculata). A morphological minimum descriptor list was prepared to monitor each selected species for at least three years. It is proposed to add descriptors to these lists for each crop on an individual basis. Flexibility in this aspect of the programme is crucial as the frequency of monitoring each morphological character depends upon the crop itself. For example, a perennial crop could be monitored monthly during flowering and the fructification period, while an annual crop should be monitored several times a month. This implies that a careful study is needed prior to beginning work on in situ conservation. Discussion Developing an integrated plan for the in situ conservation of plant genetic resources Institutional aspects A head coordinator is needed to develop a plan for the in situ conservation of plant genetic resources and to liase with the different institutions that come under the Ministries of Agriculture, Science, Technology, Environment and Higher Education. Field coordinators would then be selected at the level of municipality and province. They would come under the direction of the local and municipal governments, or other organizations such as Non-governmental Organizations, and be responsible for the protection and conservation of the home gardens in their areas. At the same time, an education campaign is needed to divulge information concerning the importance of the in situ conservation of plant genetic resources. This should involve farmers, local experts and people from local governments. Not all institutions in a province/municipality will be involved with the selected home gardens. Only institutions in, or near, the selected home garden will be involved in the work and they will choose, depending upon their means, which home gardens to be involved with. Integration with ex situ conservation, other in situ conservation programmes and existing socioeconomic programmes After demonstrating the contribution of Cuban “conucos” to the evolution of cultivated plants and the benefits of an in situ approach to conserving plant genetic resources, it will then be necessary to decide how best to preserve these agro-ecosystems. Both programmes for ex situ conservation, such as genebanks or botanical gardens, as well as in situ conservation in protected areas, should be connected with the rational utilization of natural resources and the conservation of primitive or obsolete cultivars in home gardens. Ministries and universities with activities related to the conservation and use of plant genetic resources should work together in order to establish an effective monitoring system for conserving plant genetic resources in home gardens. The conditions needed for such activities exist, as there is good coordination at the different levels of government, between the state and the municipalities and/or localities, and with farmers. A network for in situ conservation in farmer’s “conucos” should be integrated with the main socioeconomic and development programmes in the country in order to develop the sustainable use of plant genetic resources. One example is the Cuban food programme, the main objective of which is to secure an adequate supply of food by increasing food production through the use of sustainable agriculture practices. Another example is the health programme which advocates a direct and close relationship between the doctor and the community. One of its objectives is to promote the use of “green medicine”. This approach was emphasized by Prain and Piniero (1995) in a study on the community care of plant genetic resources in the southern Philippines. Often farm families have greater traditional knowledge and experience of the alternative uses of medicinal plants than doctors. It should be possible to increase the use of crop varieties, which have good yields, according to farmers, and to develop the necessary genetic base for developing breeding and biotechnological programmes, and other scientific research to identify and broaden the use of the different varieties of medicinal plants. Long-term monitoring of the variability in home gardens could be carried out by the farmers themselves, assisted by local experts from protected areas or provincial environmental units, in accordance with the national integrated strategies. A structured “conuco” network would contribute to preserving plant varieties and improve the sustainable increase of agricultural production in the country by means of the rational use of plant genetic resources with a low ecological cost. This would also help to preserve valuable traditional practices and cultural values in farm communities. The use of home gardens to conserve in situ the many varieties of cultivated species present in Cuba can be a key complementary approach to the ongoing conservation strategies and socioeconomic programmes. Acknowledgements We wish to acknowledge the support of the IPGRI for these studies and particularly the technical support of Dr Toby Hodgkin and Dr Pablo Eyzaguirre. We wish also to thank all the people that contributed to the revision of the manuscript. 16 Plant Genetic Resources Newsletter, 2000, No. 123 References Altieri, M.A. and L.C. Merrick. 1987. In situ conservation of plant genetic resources through maintenance of traditional farming systems. Econ. Bot. 41:86-96. Altieri, M.A., L.C. Merrick and M.K. Anderson. 1987. Peasant agriculture and the conservation of crop and wild plant resources. Conserv. Biol. 1:49-58. Barrios, O. 1999. Estudio de los recursos genéticos de Capsicum spp. (ají y pimiento) en Cuba. MSc Thesis, Facultad de Biología, Universidad de la Habana. Capote, R., R. Berazaín and A. Leiva. 1992. Flora and Vegetation. Pp. 26-36 in “... y tienen faxones y fabas muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. I (K. Hammer, M. Esquivel and H. Knüpffer, eds.) Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Dacal, R. and M. Rivero de la Calle. 1986. Arqueología aborigen de Cuba. Ed. Gente Nueva. Esquivel, M. and K. Hammer. 1988. The “conuco” - an important refuge of Cuban plant genetic resources. Kulturpflanze 36:451-463. Esquivel, M., L. Castiñeiras, H. Knüpffer and K. Hammer. 1989. A checklist of the cultivated plants of Cuba. Kulturpflanze 37:211-357. Esquivel, M., L. Castiñeiras and K. Hammer. 1990. Origin, classification and distribution of lima beans (Phaseolus lunatus L.) in the light of Cuban materials. Euphytica 49:89-97. Esquivel, M. and K. Hammer. 1992a. Contemporary traditional agriculture - structure and diversity of the “conuco”. Pp. 174-192 in “... y tienen faxones y fabas muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. I (K. Hammer, M. Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Esquivel, M. and K. Hammer. 1992b. The Cuban home garden “conuco”: a perspective environment for evolution and in situ conservation of plant genetic resources in Cuba. Genet. Resour. Crop Evol. 39:9-22. Esquivel, M. and K. Hammer. 1994. 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Knüpffer, eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Hodgkin, T. 1995. The role of farmers in maintaining biodiversity. Pp. 92-93 in In Situ Conservation and Sustainable Use of Plant Genetic Resources for Food and Agriculture in Developing Countries. Report of DSE/ATSAF/IPGRI Workshop, Bonn-Rottgen, Germany. Knüpffer, H. 1992. The database of cultivated plants of Cuba. Pp. 202-212 in “... y tienen faxones y fabas muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. II (K. Hammer, M. Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Leiva, A. 1992. In situ conservation of wild plants. Pp. 174-192 in “... y tienen faxones y fabas muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. I (K. Hammer, M. Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. McNeely, J.A. 1995. The role of protected areas for conservation and sustainable use of plant genetic resources for food and agriculture. Pp. 27-42 in In situ Conservation and Sustainable Use of Plant Genetic Resources for Food and Agriculture in Developing Countries. Report of DSE/ATSAF/IPGRI Workshop, Bonn-Rottgen, Germany. MINAG - Ministerio de la Agricultura. 1991. Plan de Acción Forestal para Cuba. Documento Base, Ministerio de la Agricultura, La Habana, Cuba. Niñez, V. 1986. El huerto casero: un salvavidas? Ceres 112:31-36. Ortiz, F. 1975. Los negros esclavos. Ed. Ciencias Sociales, La Habana, Cuba. Perera, A. 1986. Panorámica de las áreas protegidas en la República de Cuba. Conservando el patrimonio natural de la región neotropical. Proc. of the 27th Working Season of the IUCN Commission on Natural Parks and Protected Areas, Bariloche, Argentina. Perera, A. and P. Rosabal. 1986. 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The wild relatives of cultivated plants in the flora of Cuba. Pp. 570-577 in “... y tienen faxones y fabas muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. III (K. Hammer, M. Esquivel and H. Knüpffer, eds.) Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Salazar, R. 1996. The role of farming communities in plant genetic resources conservation and development. Pp 170-183 in Plant Genetic Resources in Vietnam. Proc. of a National Workshop, Hanoi, Vietnam, 1995. Agriculture Publishing House, Hanoi, Viet Nam. Salinas, Er. and Ed. Salinas. 1992. Features of the nature and landscapes. Pp. 174-192 in “... y Tienen Faxones y Fabas Muy Diversos a Los Nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. 1 (K. Hammer, M. Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany. Santana, E. 1991. Nature conservation and sustainable development in Cuba. Conserv. Biol. 5:13-16. Valdés, S. 1978. Indoamericanos no arawakos en el español hablado de Cuba. Ed. Ciencias Sociales, La Habana, Cuba. Valdés, S. 1986. La evolución de los indoamericanos en el español hablado en Cuba. Ed. Ciencias Sociales, La Habana, Cuba. Plant Genetic Resources Newsletter, 2000, No. 123 17 Appendix 1. Questionnaire used in the pilot project for the in situ conservation of cultivated plant variability in home gardens I. 1. 2. 3. 4. 5. 6. 7. 8. 9. NAME AND LOCALIZATION OF THE STUDY AREA (data collected from the area where the home garden is localized) Name of the area Locality Province Municipality Geographical situation General characteristics of flora and fauna Pollution Accessibility of the area State of main communications II. CHARACTERISTICS OF THE FARM FAMILY (data provided by the owner) 1. Name 2. Sex 3. Colour of skin 4. Place of birth 5. Date of birth 6. When did you arrive in this place? 7. Who lived here when you came? 8. Do you remember from which country your family came from? 9. Do you think you will leave here? If so why? 10. What is your level of education? 11. What is your civil state? 12. Family details (number of persons, age, sex and scholarship) 13. How many members of the family are economically dependent upon you (how many are economically unproductive)? 14. What is your main occupation? 15. What is your occupation (if your main occupation is not the home garden)? III. DATA ON THE SPECIFIC AREA OCCUPIED BY THE HOME GARDEN 1. Name of the home garden or the house in order to identify the locality. 2. Size of the area (ha) 3. Geographic localization (using GPS) and the distance from a well-known area. 4. Topography 5. Hydrography 6. Soil type (texture, drainage, fertility and humidity) 7. Precipitation/year 8. Yearly temperature 9. Contamination 10. How far is the home garden from your home? 11. In which state did you find this place? 12. Type of home garden according to the property (specify organization system) Private ____ State ____ Both ____ 13. Which members of your family or other persons work in your home garden? What activities do they carry out? 14. How many hours per person are dedicated to working in the garden per week and per month? 15. Do you have domestic animals? If yes what type of animals? a. Birds _____ b. Bees ____ c. Goats ____ d. Rabbits ___ e. Horses ____ f. Ovine ____ g. Pigs _____ h. Cows _____ Other ______ Why are you raising the animals (write the letter according to the above)? Subsistence ____ Sell ____ Both ____ 16. Do you remember when this land started to be cultivated? 17. Why do you cultivate this land? Subsistence ___ Sell ___ Both ___ 18. Do you have special plants in your home garden, which and why? 19. Do you have only this garden? 18 Plant Genetic Resources Newsletter, 2000, No. 123 20. How did you learn to prepare and take care of your home garden? 21. What are the main plants grown in your garden? 22. Who are you growing the plants for? 23. Which of your family’s food needs can be met by the produce of your home garden? 24. How do you obtain products that you do not produce in your garden? 25. What are the main problems that you face in your home garden? Water ___ Diseases/pests ___ Seeds ___ Equipment ___ Inputs ___ Fertilizers/pesticides ____ Diversity of GR ___ Other (specify) ___ How do you supply the inputs you need? Buy ____ Trade ____ Exchange ____ Other (specify) ____ 26. Do you receive help from the State? If yes for what? Fertilizer ____ Pesticides ___ Seeds ___ Work equipment ___ Other (specify) ___ IV. SPECIFIC DATA ON PLANTS GROWN IN HOME GARDEN 1. Species 2. Common name 3. Genetic status Wild ___ Weed ___ Landrace ____ Breeding cultivar ____ 4. When and how did you obtain this plant? 5. What is the main reason for growing this species or variety? 6. Did you cultivate another variety of this plant? If you have stopped why did you not continue? 7. Phenology of the crop Other (specify) ____ ——————————————————————————————————————————— Month 1 2 3 4 5 6 7 8 9 10 11 12 ——————————————————————————————————————————— Sowing ——————————————————————————————————————————— Harvest ——————————————————————————————————————————— 8. What is the use of this plant? 9. How do you reproduce this plant? 10. Do you produce your own seeds? 11. How do you harvest the plant? By hand ____ Mechanized ____ Both ____ 12. How do you prepare the land? By hand ____ Mechanized ____ With animals ____ Other (specify) ____ 13. Water management Dryness ____ Partial irrigation ____ Irrigation (specify) ____ 14. Has the crop been affected by pests or diseases? How do you prevent them? 15. How do you control weeds? By hand ____ Chemicals ____ Not necessary ____ 16. Do you fertilize this crop? Which type do you use? Chemical ____ Organic ____ Both ____ 17. How do you select the material for the next sowing? 18. How do you conserve/store the harvested material for propagation? Paper bag ____ Paper box ____ Crystal bottle ____ Cloth Bag ____ Soil ____ Nylon bag ____ Other (specify) ____ V. 1. 2. 3. GENERAL QUESTIONS How do you see the future of your home garden? Will someone from your immediate family keep it up after you? What will be the main effect? Would you like to cooperate with us in a long-term project to monitor the potential of your home garden to preserve valuable plants? EVALUATION 1. Main observed potentiality 2. Main observed restrictions 3. Evaluation Date: Evaluators: Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 19 - 19 22 ARTICLE Ethnobotanical testimony on the ancestors of cassava (Manihot esculenta Crantz subsp. esculenta) Antonio C. Allem Embrapa Recursos Genéticos e Biotecnologia, CP 02372, 70849-970 Brasília, DF, Brazil. Email: [email protected] Summary Résumé Resumen The hypothesis that cassava has living wild ancestors was advanced in 1987. Some authors who doubted the wild condition of the populations reported have suggested that these could be feral cassava. Over the years, an ethnobotanical record of the relationship between humans and the wild ancestors of cassava has been compiled providing strong evidence for the wild character of the material investigated. This study reports on the most important findings which are: (1) the progenitor did not escape from plantations, (2) the roots are mostly woody inedible and toxic, (3) the leaves are toxic to livestock, (4) the plant is widely regarded as a weed, and (5) the common name assigned to the plant reflects its wild condition. L´hypothèse sur l´existence de l´ancêtre sauvage vivant du manioc fut proposée à l´année de 1987. Quelsques auteurs mirent en doute l´état sauvage de populations étudiées, suggérant qu´elles pouvaient être du manioc cultivé. Pendant les années, un approche ethnobotanique sur les raports entre l´homme et l´ancêtre sauvage du manioc fut compilé. Cet approche presente une forte évidence du caractère sauvage des plantes. Les plus importantes trouvailles faites sur le terrain furent : 1. L´ancêtre n´est pas un évadé des plantations ; 2. Les racines sont presque entièrement ligneuses, immangeables et toxiques ; 3. Les feuilles sont toxiques au bétail ; 4. La plante est considérée comme une mauvaise herbe ; 5. Le nom commun attribué à la plante évoque sa condition sauvage. La hipótesis sobre la existencia de un ancestral silvestre vivo de la yuca fue propuesta en 1987. Algunos autores pusieron en duda el estado silvestre de las poblaciones estudiadas, sugeriendo que ellas podrían ser yuca cultivada. Durante los años, un abordaje etnobotánico sobre las relaciones entre el hombre y el ancestral silvestre de la yuca fue compilado. Ese abordaje presenta una fuerte evidencia del carácter silvestre de las plantas. Los más importantes hallazgos hechos en el campo fueran: 1. El ancestral no es un evadido de las plantaciones; 2. Las raíces son casi por completo leñosas, incomibles y tóxicas; 3. Las hojas son tóxicas al ganado; 4. La planta es considerada como una mala hierba; 5. El nombre común asignado a la planta evoca su condicíon silvestre. Ethnobotanical testimony on the ancestors of cassava (Manihot esculenta Crantz subsp. esculenta) Le témoignage ethnobotanique sur l’ancêtre du manioc (Manihot esculenta Crantz subsp. esculenta) El testigo etnobotánico sobre el ancestral de la yuca (Manihot esculenta Crantz subsp. esculenta) Key words: Ancestor, cassava, Manihot esculenta Crantz subsp. flabellifolia (Pohl) Ciferri, M. esculenta Crantz subsp. peruviana (Muell. Arg.) Allem Introduction Ethnobotany studies the biological, economic and cultural interrelationships between human beings and plants; more specifically, this discipline is concerned with knowledge about plants and their use by society. In the case of Manihot, researchers have long been familiar with the fact that wild relatives of cassava are known to South American rural communities (Pax 1910; Rogers 1963; Rogers and Appan 1973). Cassava is known to have several common names (Rogers and Fleming 1973; Lancaster et al. 1982). Traditionally, the vernacular names cited by writers for the wild species were mostly taken from herbarium labels. However, more in-depth information from agriculturalists and collectors of wild species is conspicuously missing from these. The most common Portuguese name found in the literature for wild relatives of cassava is “mandioca-brava”. The name “mandioca-brava” (mandioca-braba is an orthographic variant) is found in Portuguese-speaking Brazil as well as in other South American regions where Spanish, French, Dutch or English are prevalent. Rogers and Appan (1973) documented a large variety of names for wild species of cassava but again, most of these derive from herbarium labels and few are accompanied by more substantial ethnobotanical data. In contrast to shrubs and small trees, which generally go under the name wild cassava, herbs are distinguished with peculiar names, often in the diminutive form and related to the habits of the plant. For example, the name “mandioquinha-do-campo” given to M. hassleriana in southern Brazil is an allusion to its habit of invading soyabean plantations. Attributing names to plants establishes some sort of relationship between people and plants and shows that people are familiar with them to some extent. The history of sweet potato shows how social traditions can be a determining factor in the proliferation of names applied to crops (de la Puente et al. 1996). However, in respect of cassava, the names given to plants are not anecdotal as the terms used are invariably associated with an economic peculiarity of the plant (e.g. agronomic property of the root, invader of crop plantations, etc.). This study reports on the interaction discovered to exist between agriculturalists and the ancestors of cassava, viz. Manihot esculenta Crantz subsp. flabellifolia (Pohl) Ciferri and M. esculenta Crantz subsp. peruviana (Muell. Arg.) Allem. The aim is to record the vernacular historiography and the ethnobotanical knowledge related to the ancestors of cassava. This article is also concerned with the assumptions made about the origin of the materials. Three authors (Bretting 1990; Heiser 1990; Bertram 1993) have suggested that feral cassava may have been the progenitor of the crop and that the populations described as wild by Allem (1987) 20 Plant Genetic Resources Newsletter, 2000, No. 123 could have spread from cassava plantations. Subsequent publications (Allem 1994a, 1999, 2000) upheld the 1987 interpretation of the botanical origin of cassava and reaffirm the view that these genetic resources equate with the wild primary genepool of cassava. The purpose of this communication is to further strengthen the hypothesis that the materials are wild. Materials and methods Informal field interviews were conducted in areas of the Brazilian neotropics, particularly in western Amazonia. These mostly took place along the sides of the road whenever local residents showed an interest in the collecting activity or crossed the collecting area on foot or on bicycle. Three basic questions were asked of all the local residents that the team met: (1) “Do you know this plant?”, (2) “Do you know its name?”, (3) “Is it wild or cultivated by local people?”. Normally, those in transit quickly answered the questions and proceeded on their way. However, a few showed greater curiosity and stood by to observe the work of the collecting team. In these cases people expanded on their earlier answers and volunteered additional information on the plant. On such occasions the team took the opportunity to ask a few additional questions of the agriculturalists, the most important of which were: (4) “Is the plant frequent in the region?” (5) “Is the plant harvested for its roots?” (6) “Is the plant restricted to roadsides?”. Table 1 lists the municipalities where the interviews took place, the number of local people that took part in the survey and their replies to the three standard questions. The remarks of those who further expanded on their replies were recorded in their native tongue and are given, together with a translation, in Table 2. The field survey was carried out from 1986 to 1996, most work being done in 1992 and 1993. The herbarium vouchers of the author are deposited at the Embrapa Recursos Genéticos e Biotecnologia Herbarium (CENARGEN) in Brasília. Most of the testimonies were recorded on sheets of paper as the comments were inappropriate for the type of notebook being used. This explains why some of the quotations given here are missing from the respective herbarium labels. Discussion The first interviews took place in 1986 while collecting in the Brazilian Amazonian states of Mato Grosso and Rondônia. Simultaneously, some data was obtained in the central state of Goiás and in the northwestern Amazonian state of Acre. All the people interviewed and listed in Tables 1 and 2 answered the questions about the ancestors of cassava to some extent. This showed that all were familiar with the plant in question, no matter whether the plant was found as a ruderal or bordering the woods. No one seemed to doubt the wild character of the materials. One aspect of the plant that drew the attention of the team was the fact that although inedible to humans, a number of people reported that armadillos and wild pigs feed on the roots. In three locations the ancestors of cassava were described as a weed. When João Xavier, an agriculturalist living at Colônia Bela Vista in the state of Mato Grosso was interviewed on 14 May 1992, he could not explain why wild Manihot was found growing on his plantation among papaya, banana trees and a few plants of cultivated cassava as well as common beans. It took considerable time for the team to infer what had happened, i.e. wild cassava Table 1. Replies to three standard questions about the ancestor of cassava: (1) Do you know this plant? (2) Do you know the name of this plant? (3) Is this had sprouted back from dormant plant wild or cultivated in the area? rootstocks left underground when the humid forest was cleared. This Municipality State Date Voucher No. of Reply† also explained the find of two exAgriculturalists amples of the subspecies peruviana Niquelândia Goiás 4.3.86 3469 1 y; mb; w on a derelict maize plantation at Pontes e Lacerda Mato Grosso 12.5.86 3530 1 y; mb; w Colônia Bela Vista. Voucher 4033 Cacoal Rondônia 14.5.86 3547 1 y; mb; w documents the visit made on 8 Ariquemes Rondônia 18.5.86 3571 1 y; mb; w June 1992 to the farm of Gentil Vila Rica Mato Grosso 26.5.86 3605 1 y; mb; w Rodrigues. There the team found Pontes e Lacerda Mato Grosso 13.11.91 3980 1 y; mb; w Lambari Mato Grosso 23.5.92 3987 1 y; mb; w shrubs up to 2 m tall of the subspeLambari Mato Grosso 23.5.92 3988 1 y; mb; w cies peruviana growing together with Pontes e Lacerda Mato Grosso 24.5.92 3992 1 y; mb; w maize plants, squashes and other Pontes e Lacerda Mato Grosso 8.6.92 4033 1 y; mb; w minor crops. The morphology of Lambari Mato Grosso 3.6.93 4107 3 y; mb; w the plants resembled that of cultiLambari Mato Grosso 3.6.93 4108 1 y; mb; w Lambari Mato Grosso 3.6.93 4109 1 y; mb; w vated cassava and the plantation Lambari Mato Grosso 3.6.93 4110 1 y; mb; w was encircled by the highly deLambari Mato Groso 3.6.93 4111 1 y; mb; w graded remnants of the tropical Lambari Mato Grosso 3.6.93 4112 1 y; mb; w rainforest. As in the previous case Pontes e Lacerda Mato Grosso 7.6.93 4117 2 y; mb; w mentioned, it became evident that Pontes e Lacerda Mato Grosso 8.6.93 4121 1 y; mb; w Porto Velho Rondônia 11.6.93 4140 1 y; mb; w the wild cassava plants growing in Porto Velho Rondônia 11.6.93 4141 1 y; mb; w the plantation originally grew in Porto Velho Rondônia 11.6.93 4142 1 y; mb; w the rainforest and had regrown Guajará-Mirim Rondônia 11.6.93 4144 1 y; mb; w from dormant rootstocks after the Rio Branco Acre 14.6.93 4149 1 y; mb; w plot had been cleared to make † y = yes; mb = mandioca brava; w = wild. room for agriculture. Plant Genetic Resources Newsletter, 2000, No. 123 21 Table 2. Replies expanding on the ethnobotanical knowledge of the ancestor of casssava Municipality State Niquelândia Goiás Rondonópolis Voucher No. of agriculturalists Reply Translation 4.3.86 3467 2 Mato Grosso Mato Grosso 8.5.86 3515 1 9.5.86 3516 1 Pontes e Lacerda Pontes e Lacerda Mato Grosso Mato Grosso 12.5.86 3531 1 12.5.86 3532 1 Ninguém come; em outras áreas faz-se farinha e polvilho dela, mas não aqui. Mandioca-brava. A raiz é lenhosa e não é comida. Mandioca-brava. A gente não come porque é tóxica e a raiz é um pau. Mandioca-brava. O tatu come a raiz dela. Mandioca-brava. É abundante na mata. Vem fácil quando desmata. Ninguém planta. Catéte (porco-do-mato) come a raiz. É praga. Cacoal Rondônia 14.5.86 3545 2 Cacoal Rondônia 14.5.86 3546 1 Ariquemes Rondônia 18.5.86 3572 1 Lacerdinha Mato Grosso 13.11.91 3979 1 Pontes e Lacerda Mato Grosso 24.5.92 3991 2 Lacerdinha Mato Grosso 24.5.92 3994 1 É nativa. Dá raiz, mas não presta. Na minha lavoura de milho tá assim dela. Ariquemes Rondônia 27.5.92 4009 1 Porto Velho Rondônia 28.5.92 4012 1 No Ceará nós conhecemos ela por ‘maniçoba’. Esta mandioca tem muito no mato. Não dá raiz. Lacerdinha Mato Grosso 8.6.92 4033 1 O gado come desta mandioca -brava se a pastagem não está boa. O animal não digere, empanzina e morre. Lambari Mato Grosso 9.6.92 4034 1 Lambari Mato Grosso 9.6.92 4035 5 A turma aqui chama ela de mandioca-brava. Todos riram à menção de que podia ser mandioca cultivada. Souza disse que conhecia a planta e que havia muito dela nas matas próximas, de propriedade de Dr. Armando. Lambari Mato Grosso 14.5.92 ? 1 It is not eaten; in other areas flour and ‘polvilho’ are made of it, but not here. Wild cassava. The root is woody and it is not eaten. Wild cassava. We do not eat it because it is toxic and the roots are very hard. Wild cassava. The armadillo eats the roots. Wild cassava. It is abundant in the woods. It sprouts back easily when deforestation takes place. Nobody plants it. Catéte (wild pigs) eat the roots. It is a weed. Wild cassava. It is a serious weed in the area. Wild cassava, bushwood cassava. When the forest is fallen, the plant sprouts back vigorously. It is highly toxic. Pigs die if fed on leaves. It is a weed. In 1982 my father planted some stakes and the harvest produced roots of fair quality, from which only flour was made since the root is toxic. A good harvest was obtained within a year. The plant propagates well through stakes. Wild cassava. It occurs in the woods. It is fond of rocky outcrops. The root only produces ‘small potatoes’. It is wild cassava. It is not cultivated. It is a native of the region. Nobody plants it. The roots are minuscule. It is wild cassava. It is not planted here. It is a weed. There is plenty of it around. If you prune it back, it sprouts back vigorously. It is native. It produces roots but they are not good. There is lots of this wild cassava in my maize plantation. In Ceará we call it ‘ maniçoba’. There is plenty of this cassava in the bush wood. The plant does not produce edible roots. Cattle eat wild cassava if the pasture is not good. The animal does not digest it, the stomach swells and the animal dies. Folks know it by the name mandioca-brava All laughed at the mention that the plant could be cassava. Souza said he knew the plant and that there was plenty of it in the nearby woods of the estate of Dr. Armando. If you cut it back, it sprouts back. Rondonópolis Date Mandioca-brava. É praga séria na região. Mandioca-brava; mandioca-do-mato. Quando corta a mata, aí é que ela vem furiosa. Altamente tóxica. Folhas dadas a porcos, matam-nos. Em 1982 o pai plantou estacas dela e deu raiz boa, de onde fizemos farinha, porque a raiz é tóxica. Colhemos com um ano de plantada. Pega bem de estaca. Mandioca-brava. Dá nas matas. Gosta mesmo é de afloramentos rochosos. A raiz só dá ‘batatinhas’. É mandioca-brava. Não é cultivada. É nativa da região. Ninguém planta. Dá uma raizinha assim. É mandioca-brava. Não plantam aqui. É praga. É o que mais tem. Roçou, ela vem” Quando roça, ela vem. 22 Plant Genetic Resources Newsletter, 2000, No. 123 Municipality State Date Voucher No. of agriculturalists Reply Translation Lacerdinha Mato Grosso 24.5.92 ? 1 Tá atrás de mandioca? Tá pegando mandioca? Esta não presta, não é mandioca. Lambari Mato Grosso 10.6.92 4037 1 Dá pau. Não presta. Lambari Mato Grosso 10.6.92 4037 1 Anápolis Goiás 18.5.92 4047 1 É mandioca-brava. É nativa. O catitu come. Dá uma raizinha assim. Os fazendeiros caçam implacavelmente a mandioca porque as folhas são tóxicas ao gado. Se os animais comem folhas frescas, os estômagos incham e o animal morrre. As folhas da mandioca cultivada não são tóxicas. Hinterlândia Goiás 18.5.92 ? 1 Isto é mandioca-brava. Não produz raízes. Nativa da região. Não é fugida de plantações de mandioca ao redor. Rio Branco Acre 14.6.93 4149 1 Faz mal de comer. É selvagem. Are you after cassava? Are you collecting cassava? This is rubbish, it is not cassava. The roots are hard, it is no good. It is wild cassava, it is native. Wild pigs eat the roots. It produces a minute root. Farmers search for its ancestor implacably because the leaves are toxic to cattle, their stomachs swell and they die if they eat fresh leaves. In contrast, the leaves of the domesticated variety are not toxic. This is wild cassava. It does not yield roots. It is native to the area and it has not escaped from nearby cassava plantations. It is no good to eat it is wild. Three young boys (voucher 4107) laughed at the idea that “mandioca-brava” could be the ancestor of cultivated cassava. The same type of reaction occurred in Colônia Bela Vista, and in the municipality of Lambari on a plot of land donated by the federal government and shared among 20 families. When the team asked about the subspecies peruviana, the wife of the landless José Lopes de Souza, a migrant from the Brazilian state of Minas Gerais, and three visiting neighbours, laughed at the mention of feral cassava. Agriculturalist José Lopes de Souza, 39, offered to take the collecting group to an area where there was still plenty of this wild cassava (see voucher 4035). The results of this exploratory mission are reported in Allem (1994b). A particularly enlightening view of the wild state of the material took place in the district of Lacerdinha on 24 May 1992, at km 323 of BR-174 highway (see Table 2). A 12-year-old boy who saw the team collecting seeds of the subspecies peruviana stopped and dismounted from his bicycle thinking that the team were collecting the plant by mistake (dialogue given in Table 2). Similarly, two men awaiting a bus on 24 May 1992, at km 208 of BR-174 highway, eventually intervened after 20 min of watching the team as they were unable to understand why seeds of the subspecies peruviana were being collected from along the embankment (see voucher 3991 in Table 2). A final revealing episode on the wild character of the plant occurred 63 km NW of the municipality of Ariquemes on BR-364 highway (voucher 4009, Table 2). A migrant from the Brazilian northeastern state of Ceará, walking along the road, addressed the team saying “In Ceará we know it as maniçoba”. This testimony was relevant because it strengthened the hypothesis of the wild nature of the plant by associating its morphology with that of wild relatives from northeast Brazil. In northeast Brazil, a woody species of Manihot living in the xerophilous vegetation known as Caatinga, is called maniçobas. To sum up, the rich folklore and wisdom of the inhabitants of the Brazilian neotropics indicate that wild relatives of cassava still abound. References Allem, A.C. 1987. Manihot esculenta is a native of the neotropics. Plant Genet. Resour. Newsl. 71:22-24. Allem, A.C. 1994a. The origin of Manihot esculenta Crantz (Euphorbiaceae). Genet. Resour. Crop Evol. 41:133-150. Allem, A.C. 1994b. Manihot germplasm collecting priorities. Pp. 87-110 in Report of the First Meeting of the International Network for Cassava Genetic Resources. International Crop Network Series No. 10. IPGRI, Rome, Italy. Allem, A.C. 1999. The closest wild relatives of cassava (Manihot esculenta Crantz). Euphytica 107:123-133. Allem, A.C. 2000. The origins and taxonomy of cassava (Manihot esculenta Crantz subspecies esculenta). In Cassava: Biology, Production and Utilization (R.J. Hillocks, M.J. Thresh and A.C. Bellotti, eds.). CABI International, Oxford, UK (in press). Bertram, R.B. 1993. Application of molecular techniques to genetic resources of cassava (Manihot esculenta Crantz, Euphorbiaceae): interspecific evolutionary relationships and intraspecific characterization. PhD thesis, University of Maryland, U.S.A. Bretting, P.K. 1990. New perspectives on the origin and evolution of New World domesticated plants: introduction. Econ. Bot. (Suppl.) 44:1-5. Heiser, C.B., Jr. 1990. New perspectives on the origin and evolution of New World domesticated plants: summary. Econ. Bot. (Suppl.) 44:111-116. Lancaster, P.A., J.S. Ingram, M.Y. Lim and D.G. Coursey. 1982. Traditional cassava-based foods: survey of processing techniques. Econ. Bot. 36:12-45. Pax, F. 1910. Euphorbiaceae-Adrianeae. In Das Pflanzenreich, IV. (A. Engler, ed.). 147.II. 44:1-111. Puente, de la F., D.F. Austin and J. Díaz. 1996. Common names of the sweet potato (Ipomoea batatas) in the Americas. Plant Genet. Resour. Newsl. 106:13-15. Rogers, D.J. 1963. Studies of Manihot esculenta Crantz and related species. Bull. Torrey Botanical Club 90:43-54. Rogers, D.J. and Appan, S.G. 1973. Manihot and Manihotoides (Euphorbiaceae), a computer-assisted study. Flora Neotropica, monograph no. 13. Hafner Press, New York, USA. Rogers, D.J. and H.S. Fleming. 1973. Monograph of Manihot esculenta Crantz. Econ. Bot. 27:1-114. Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 23 - 23 27 ARTICLE Reincorporación del fríjol carauta (Phaseolus lunatus L.) a la agricultura tradicional en el resguardo indígena de San Andrés de Sotavento (Córdoba, Colombia) Gustavo Ballesteros P.¹, Asterio Torres G.²* y Martha Barrera³ ¹ Universidad de Córdoba, Montería, Colombia ² Instituto Técnico Industrial y Agropecuario de Campeche, Baranoa, Atlántico Colombia. Email: [email protected] ³ Unidad Municipal de Asistencia Técnica, Agropecuaria (UMATA), Polonuevo, Atlántico, Colombia Resumen Résumé Summary Cuatro especies de Phaseolus (P. vulgaris, P. lunatus, P. Coccineus y P. acutifolius) han proporcionado, desde tiempos prehispánicos, alimento a los pueblos de América, que las convirtieron, junto con el maíz, en su dieta básica. En la Costa Atlántica (Costa Caribe) de Colombia se ha cultivado así el fríjol zaragoza o carauta (Phaseolus lunatus L.) y ha tenido gran aceptación solo o asociado con yuca (Manihot esculenta), maíz (Zea mays), guandú (Cajanus cajan), millo (Sorghum sp) y ñame (Dioscorea alata). Este fríjol, por su gran rusticidad, su valor proteico y su pertenencia a la cultura local, puede complementar la dieta de hidratos de carbono predominante en la ‘provincia’ Zenú. Por ello, el presente trabajo se realizó, entre 1990 y 1993, para promover el cultivo del fríjol carauta en tres comunidades del resguardo indígena de San Andrés de Sotavento. Se consideraron los siguientes objetivos: realizar colectas de fríjol carauta en la Costa Atlántica colombiana, evaluar las características agronómicas de las accesiones colectadas, y conocer el grado de aceptabilidad y la posibilidad de reinserción de las accesiones. De las 16 accesiones evaluadas, sólo 8 son homogéneas en cuanto a su rendimiento, con un coeficiente de variación que oscila entre 10.3% y 28.2%. Su contenido de ácido cianhídrico (compuestos cianógenos) oscila entre 17.6 y 96.0 ppm, que las hace aptas para el consumo humano. Por estas características, las ocho accesiones escogidas se consideran promisorias para la zona del Resguardo Indígena de San Andrés de Sotavento. Después de 3 años de iniciado el estudio, sólo el 20% de los productores han continuado sembrando el frijol carauta como componente adicional de los sistemas de producción basados en la trilogía maízyuca-millo. Esta baja reinserción se explica por la escasa demanda de carauta en los mercados regionales y por la competencia de otras leguminosas, como Vigna unguiculata y Vigna sesquipedalis. Quatre espèces de Phaseolus (P. vulgaris, P. lunatus, P. coccineus, P. acutifolius) ont nourri de nombreuses populations américaines depuis l’arrivée de Colomb dans le Nouveau Monde; haricots et maïs étaient les aliments de base de ces populations. Sur la côte caraïbe (ou atlantique) de la Colombie, la variété de haricot carauta (Phaseolus lunatus L.) a été depuis lors une composante importante du régime alimentaire avec le manioc (Maniot esculenta), le maïs (Zea mays), le pois cajan (Cajanus cajanus), le sorgho (Sorghum sp.) et l’igname ailée (Dioscorea alata). Ce type de haricot, compte tenu de ses qualités alimentaires, de sa valeur nutritionnelle et de son rapport avec la culture locale, peut contribuer au régime alimentaire à base de glucides des populations Zenú. Pour cette raison, les présents travaux ont été lancés en 1990-1993 en vue de promouvoir le haricot carauta dans trois communautés de la Réserve indienne de San Andrés de Sotavento. Les principaux objectifs de ces travaux sont les suivants: constituer une collection de haricots carauta pour la côte atlantique colombienne; évaluer les caractères agronomiques des accessions collectées; estimer le niveau d’acceptabilité et la réintroduction potentielle des accessions de haricots. L’étude se penche sur les résultats suivants: sur 16 accessions évaluées, 8 seulement ont affiché un comportement uniforme. Ainsi, le coefficient de variation se situe entre 10,3 % et 28,2 %. Par ailleurs, les accessions ont une teneur en cyanure qui varie entre 17,6 et 96 ppm; elles peuvent donc être consommées sans danger. En raison de ces caractéristiques, le haricot carauta est considéré comme une accession prometteuse pour la Réserve indienne de San Andrés de Sotavento. Après trois années d’efforts pour le réintroduire, seuls 20% des producteurs cultivent encore le haricot carauta et l’utilisent comme complément dans leur système de production basé sur le maïs, le manioc et le sorgho. On peut attribuer cette adoption limitée à la faible demande de haricots carauta dans le commerce local et à la présence d’une variété de haricot compétitive sur le marché. Four species of Phaseolus (P. vulgaris, P. lunatus, P. coccineus, P. acutifolius) have provided food to many American peoples since the arrival of Columbus in the New World; beans and corn made the basic diet of those cultures. In the Caribbean (or Atlantic) Coast of Colombia, the Lima bean (Phaseolus lunatus L.) has been since then an important component of the diet together with cassava (Maniot esculenta), corn (Zea mays), guandú (Cajanus cajanus), millo (Sorghum sp.) and ñame (Dioscorea alata). This type of bean, given its food quality, nutritious value and relationship to the local culture, can contribute to the mainly carbohydrate diet of the Zenú culture. For that reason, the present work was launched in 19901993 to promote the Lima bean in three communities of the San Andrés de Sotavento Indian Reserve. The main objectives of this work are the following: to make a Lima bean collection for the Colombian Atlantic Coast; to evaluate the agronomic traits of the collected accessions; to estimate the acceptability level and the potential reintroduction of the bean accessions. The following results are discussed in this work: out of 16 evaluated accessions only 8 had a uniform performance. Thus, the variation coefficient lies between 10.3% and 28.2%. Besides, the accessions have a cyanide content that varies between 17.6 and 96 ppm; therefore, they can be consumed safely. Due to these characteristics, the Lima beans are considered promising accessions for the Indian Reserve of San Andrés de Sotavento. After 3 years of reinsertion effort, only 20% of the producers are still cropping the Lima bean and using it as a complement in their production system based in corn, cassava and sorghum. The reasons for this low adoption are probably the low demand for the Lima beans in the local market and the presence of a competitve bean variety in the market. Reincorporación del fríjol carauta (Phaseolus lunatus L.) a la agricultura tradicional en el resguardo indígena de San Andrés de Sotavento (Córdoba, Colombia) Réintroduction du haricot de Lima (Phaseolus lunatus L.) dans l’agriculture traditionnelle au bénéfice des communautés autochtones de San Andrés de Sotavento (Córdoba, Colombie) Reincoportating Lima bean (Phaseolus lunatus L.) into the traditional agriculture protecting indigenous communities of San Andrés de Sotavento (Córdoba, Colombia) Key words: Collecting, Colombia, Lima bean, Phaseolus lunatus, reintroduction, traditional farming 24 Plant Genetic Resources Newsletter, 2000, No. 123 Introducción El fríjol lima (Phaseolus lunatus L.), denominado carauta, caraura y zaragoza en la Costa Atlántica (Costa Caribe) de Colombia, es una leguminosa de grano que ha estado ligada a la cultura y a las tradiciones indígenas y mestizas de esta región de Colombia. Este fríjol se distribuye desde la península de la Guajira hasta el Golfo de Darién, en los límites con Panamá. Sin embargo, a excepción de algunas zonas de sabana de Sucre y del Bajo Magdalena, su producción y su consumo son marginales y no se vende en los mercados regionales. En el Resguardo Indígena de San Andrés de Sotavento, perteneciente a la etnia Zenú, existe la memoria histórica del cultivo de carauta y se han mantenido algunas tradiciones agrícolas alrededor de la asociación del maíz, la yuca y el ñame. Se consideró, por tanto, pertinente iniciar en la zona un programa de fomento del cultivo y hacer allí una evaluación de la aceptación del fríjol entre las comunidades indígenas. Preferencias regionales El género Phaseolus ha sido un importante recurso agrícola en América y en el viejo mundo, donde se ha consumido como semilla seca, como vaina verde o como un producto procesado. Es una importante fuente de proteína y de calorías para la dieta humana en Africa y en América, donde es un suplemento de la dieta calórica basada en maíz, yuca, ñame y arroz (Oriza sativa). El incremento del costo de la proteína animal en Europa y América del Norte ha convertido algunas especies de fríjol en fuente importante de proteína. Cada país y cada zona geográfica tiene una preferencia respecto al color y al tamaño de la semilla de fríjol, la cual proviene de la dispersión (y el consiguiente consumo) de ciertos tipos de fríjol en el pasado. En la Costa Atlántica colombiana, las leguminosas preferidas son el fríjol criollo (Vigna unguiculata), en las variedades de semilla blanca y roja, que se consume abundantemente durante la semana santa; la habichuela (Vigna sesquipedalis) cuyas vainas y semillas se consumen tiernas; el guandú (Cajanus cajan); y la carauta (Phaseolus lunatus). El nombre carauta se deriva, posiblemente, de los carautas, una tribu caribe que se asentó entre los ríos Sinú y León, cerca de la frontera colombo-panameña. La carauta tiene demanda en los mercados de Barranquilla como semilla tierna, tipo sieva de color blanco, que se produce en las riberas del Bajo Magdalena. Asimismo, se expende en los mercados de las sabanas de Sucre (Sincelejo, Corozal, Ovejas, Chalán y Colosó) y de Bolívar (El Carmen, San Juan y San Jacinto), como semilla seca y tierna, tipo sieva y papa, de color rojo con vetas negras y blanco con vetas rojas. En esas sabanas se siembran accesiones volubles y arbustivas alrededor de los cultivos de yuca, maíz, millo y ñame; la carauta es un componente importante de la dieta rural pues todas las tardes se consume este fríjol con arroz. Diferentes análisis indican que el fríjol carauta tiene 20% de proteína que, aunque de buen valor biológico, alto contenido de lisina y gran digestibilidad, es deficiente en treonina. Este fríjol posee un glucósido cianogénico, la faseolunatina, y la enzima linamarasa, los cuales se hidrolizan en presencia de humedad en la molienda y liberan glucósidos generando ácido cianhídrico (HCN), cuyo contenido varía de 10 a más 300 mg/100g de fríjol. Se acepta con frecuencia que las semillas coloreadas de fríjol lima tienen un alto contenido de glucósidos, aunque algunos estudios reportan ausencia de correlación entre ambos caracteres. Muchos genotipos comerciales tienen sólo de 1 a 8 ppm de HCN en la semilla, en la que generalmente se acepta una concentración límite de 100 a 200 ppm de HCN. Metodología Las colectas se hicieron en la Costa Atlántica colombiana y se dedicaron a las variedades criollas de fríjol carauta cultivadas por los pequeños agricultores de la región. Durante la etapa de exploración, en los sitios de colecta se tomaron datos según el formulario de recolección de fríjol del Instituto Internacional de Recursos Fitogenéticos (IPGRI) y del Centro Internacional de Agricultura Tropical (CIAT). Asimismo, mediante entrevistas y encuestas con los productores se amplió la información sobre la etnobotánica de la especie. Los materiales recolectados fueron enviados al CIAT con el fin de ampliar la colección mundial de germoplasma de fríjol lima; gran parte de estas accesiones ya hacen parte de los catálogos de ese Centro. La semilla colectada era insuficiente para establecer las accesiones entre las comunidades indígenas del resguardo de San Andrés de Sotavento, en Córdoba; se montó, por tanto, un ensayo de multiplicación de semillas durante 1988B, en los predios de la Universidad de Córdoba, en las condiciones siguientes: temperatura promedio de 29 ºC, humedad relativa del 85%, precipitación anual de 1200 mm, suelos francos y altura de 19 m.s.n.m. Las plantas del ensayo se sembraron a 1 m entre una y otra y se montó un sistema de espalderas de alambre sostenidas por postes de madera. Las plantas manifestaron un gran desarrollo vegetativo debido a la intensa precipitación que cayó durante el tiempo de cultivo. Los problemas de sanidad del ensayo fueron los crisomélidos (Diabrotica sp., Omopoita sp., Cistena sp., Diphaulaca sp., Ginandrobrotica sp.), las chinches de encaje(Gargaphia sp.) y el virus del mosaico (VMB). Se manifestó asimismo un gran porcentaje de variación en la descendencia de algunos genotipos debido a la alogamia ocurrida entre estos materiales de fríjol. Partiendo de estos datos, se montó otro ensayo en 1990 en la finca Mina de Oro, localidad de Comején, en Purísima, Córdoba, perteneciente al Resguardo Indígena de San Andrés de Sotavento, en las condiciones siguientes: suelos ácidos de textura arenosa, terreno de topografía ondulada, temperatura promedio de 29ºC, humedad relativa de 85%, precipitación anual de 1200 mm y una altitud de 20 m.s.n.m. El suelo se preparó según la tecnología tradicional de la zona: pica, quema y limpia. La siembra manual se hizo colocando tres semillas por sitio y raleando a los 15 días para dejar sólo una planta, a un metro entre plantas y a un metro entre surcos. El ensayo se hizo en parcelas de 54 m 2, organizadas en un diseño de bloques al azar. Había 10 plantas por parcela y se tomaron datos de fenología, de componentes del rendimiento, de área foliar en la antesis y del índice de área foliar. Plant Genetic Resources Newsletter, 2000, No. 123 25 Asimismo, en el laboratorio de utilización de yuca del CIAT se determinó el contenido de HCN de la semilla por el método de Cooke. Los granos cocidos y aliñados (de igual forma en cada caso) fueron presentados a un panel compuesto por 50 indígenas de la comunidad de Comején para evaluar la aceptabilidad de los materiales. A las variables de medición y de recuento se les aplicó un análisis de estimación de intervalos. En 1991 se repartió, en la localidad de Comején, semilla mezclada de carauta entre 42 familias, con la recomendación de que la sembraran en sus parcelas. En 1992 se repartió de nuevo semilla de una de las muestras promisorias (Unicor 3) entre las mujeres de la comunidad para que la sembraran en los patios. En 1993B se hizo un recorrido para evaluar la presencia de este fríjol en los campos de los agricultores de Comején. Se evaluaron además las condiciones de sanidad del cultivo y el manejo de éste en las parcelas y en los patios. Finalmente, se hizo una encuesta a las mujeres de esta comunidad. Resultados Etnobotánica del cultivo El fríjol carauta se encuentra distribuido en toda la Costa Atlántica (Costa Caribe) de Colombia, especialmente en los departamentos de Atlántico (Juan de Acosta, Tubará, Usiacurí y Ponedera), Bolívar (El Carmen, La Casona, San Jacinto y San Juan), Sucre (Ovejas, Colosó, Chalán y Don Gabriel), Magdalena (Sevilla, Guaimaro, Guacamayal y Sierra Nevada), Córdoba (Montería, Tierralta y Valencia), y en el Urabá Antioqueño. La denominación más usual es carauta, aunque en algunos sitios se conoce como haba, zaragoza, garbanzo o con nombres que reflejan la forma y el color de la semilla, como panchita, fríjol rojo, carita de santo, huevo de codorniz y venezolana. En los sitios de colecta se desconoce su procedencia; los campesinos lo consideran nativo porque se ha cultivado de generación en generación. En 50% de los casos, aproximadamente, los cultivos son de patio y consisten en unas 10 plantas alrededor de la vivienda. Sólo en los departamentos de Atlántico y Sucre lo cultivan en campo abierto pero no llega a 0.5 ha el área sembrada por familia (500 a 1500 plantas). A excepción del área tabacalera de Sucre, en ninguna zona se mecaniza la tierra sino que usan el procedimiento tradicional de roza, tumba y quema. Se utilizan las cercas o ramas de árboles como tutores (en Sucre), se intercala con la yuca o el maíz (en Magdalena) o se asocia con yuca y millo (en Atlántico). En la siembra no se aplica ningún producto que proteja la semilla. Por lo regular, se siembra a distancias de 3 m entre plantas, cuando se hace en el patio; en el campo, a de 2 m entre plantas y a 2 ó 3 m entre surcos. Para sembrar utilizan espeques de madera, colocando 3 a 4 semillas por sitio. En ninguna de las zonas del ensayo se fertiliza y en todas se hace control manual de las malezas. Las siembras se hacen a principios de la época de lluvias (abril-mayo) o a principios del estiaje en los terrenos aluviales de las riberas del río Magdalena. Son comunes los ataques de crisomélidos (Cerotoma sp., Diabrotica sp., Diphaulaca sp., Colapsis sp., Cistena sp.). En Córdoba y Magdalena se ha encontrado en las semillas el coleóptero perforador de la semilla (Hipotenemus sp.), el cual se introduce por el hilum y hace galerías dentro de la semilla; se han contado hasta 24 insectos por semilla y las accesiones más atacadas son Unico 3 y Unico 7. Se encontraron además plantas con fuertes ataques de la chinche de encaje (Gargaphia zanchesi). En las riberas del Magdalena es común el virus del mosaico (VMB). La producción de grano se inicia 3 meses después de la siembra; el fríjol se consume como semilla tierna y como semilla seca. En las zonas rurales de los municipios de Ovejas, Colosó y Chalán, la comida tradicional de la tarde es arroz con carauta, en proporción de 1 libra de carauta por 1 libra de arroz. La carauta seca se pone a ablandar en agua y así se elimina un poco el cianuro. No hay todavía un cálculo preciso del rendimiento de este fríjol pues la cosecha es escalonada y no se llevan estadísticas. En la mayoría de los casos, la producción es para autoconsumo aunque en las ciudades donde hay demanda (Barraquilla, Ovejas, El Carmen) se colocan excedentes en el mercado que llegan a tener altos precios (Col$800/lb). El fríjol almacenado es atacado con frecuencia por el gorgojo pintado (Zabrotes subfasciatus). Según los campesinos encuestados, el fríjol carauta necesita menos tiempo para la cocción que los fríjoles andinos (Phaseolus vulgaris); además, no produce malestar estomacal y necesita pocos cuidados en el campo debido a su rusticidad. Evaluacion de los materiales colectados Los materiales colectados aparecen en el Cuadro 1. Se les asignó un código compuesto por las siglas Unicor, que corresponde al lugar del primer depósito, o sea, la Universidad de Córdoba, y un número según el orden en que fueron colectados. El CIAT les asignó un código, compuesto por una letra y un número que corresponde a los 3 tipos: sieva, papa y lima grande. Predomina en los materiales el tipo sieva y son de hábito indeterminado trepador. Las plántulas tienen hipocotilos verdes o verdes con pigmentos púrpura y los tallos variaron del verde al púrpura. En el haz de las hojas primarias se presentaron, en algunos genotipos, manchas plateadas a lo largo de las nervaduras. Las hojas son pubescentes, con el folíolo terminal de forma lanceolada, ovado-lanceolada o redonda. Las flores son de color blanco o lila con las alas cerradas o superpuestas, en la mayoría de los casos. Sólo la Unicor 6, que tiene apariencia de fríjol lima grande, tenía las alas abiertas. Las etapas vegetativas (V0, V 1, V 2 y V3) fueron uniformes en los materiales; la etapa V4, sin embargo duró 34 días en las accesiones Unicor 2, 8 y 10 y 75 días en la Unicor 16. Las etapas reproductivas, mostraron un comportamiento diferencial en todos los materiales: la etapa R5 tuvo de 7 a 22 días de duración, la R6 osciló entre 5 y 9 días, la R7 de 6 a 20 días y la R8 de 14 a 22 días. En cuanto al rendimiento, los materiales más rendidores son Unicor 6, Unicor 4 y Unicor 7, con 1254.0, 879.1 y 704.0 kg/ha, respectivamente. Los mayores niveles de área foliar en la antesis se registraron en la accesión Unicor 2 (6726 cm2/planta); en la Unicor 10 ese valor fue de 2746 cm2/planta. 26 Plant Genetic Resources Newsletter, 2000, No. 123 Cuadro 1. Colección regional del fríjol carauta en la Costa Caribe de Colombia Nombre local Sitio de origen Carauta Haba Fríjol rojo Zaragoza Zaragoza Roja Carauta Carauta Carauta Carauta Carauta Carauta Carauta Carauta Carauta Ponchita Carita de Santo. Valencia (Córdoba) Santafé de (Antioquía) Loma Grande (Urabá) J.de Acosta (Atlántico) Tubará (Atlántico) Cansona (Bolívar) Ayapel (Córdoba) Sampués (Sucre) Chalán (Sucre) Colosó (Sucre) Tuchín (Córdoba.) Tierralta (Córdoba) Ponedera (Atlántico) Usiacurí (Atlántico) † Altura (m s.n.m.) Latitud Longitud Código Unicor Código CIAT 55 28 100 720 25 43 150 8°15’N 6°10’N 8°5’N 10°50’N 10°40’N 9°35’N 8°18’N 9°10’N 9°35’N 76°0’W 7530W 7620W 75°03W 75°20’W 7510W 7509W 7520W 7525W G26322 G26313 G16312 G26316 G26314 G26320 G26317 G26324 150 50 77 8 100 9°20’ 9131 8°12’ 1038N 1045N 7515 7530W 76°5’W 7446W 7459W Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor Unicor 58 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 † G26323 † G26321 G26319 G26325 G26315 No fueron donados. Contenido de ácido cianhídrico (HCN) El alto contenido de compuestos cianogénicos (ácido cianhídrico) es una característica indeseable en algunas accesiones de fríjol carauta, pues le da un sabor amargo a las semillas. En el Cuadro 2 se observa que los contenidos de HCN oscilan entre 17.6 ppm, en la accesión Unicor 1, y 212 ppm en Unicor 6; esta última es el material que supera en este rubro los límites permitidos por la Organización Mundial de la Salud. Efectos de la reincorporación El 60% de los productores de grano que recibieron, en 1990, semilla mezclada no sembraron carauta alegando que las semillas se habían dañado por ataques de insectos. Por tanto, 40% sembraron el primer año, aunque sólo la mitad de ellos (20%) han conservado la semilla. La mayoría de sembró este fríjol en los patios, cerca de las casas, y utilizaron como tutores las cercas y las ramas de los árboles. Al juzgar la aceptabilidad del fríjol como alimento, todos manifestaron que les gusta la carauta (P. lunatus), la habichuela (Vigna sesquipedalis) y el fríjol criollo(Vigna unguiculata). Cuadro 2. Contenido de cianógenos (HCN) en las semillas secas del fríjol carauta Accesión HCN (ppm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17.6 21.6 20.3 60.0 43.0 212.0 24.0 51.0 38.0 39.3 25.0 96.0 36.3 34.0 35.6 27.3 Según la encuesta aplicada a las mujeres que recibieron semilla de Unicor 3 a principios de 1993, a todas les gusta carauta y un 50% de ellas la sembraron el primer año. En cuanto al consumo, el 70% las prefieren tiernas (verdes) y un 30% como semilla seca. Preparan el fríjol como sopa, mote, con arroz y con guisos. Al momento de la evaluación del estado de las plantas (agosto de 1993), éstas se hallaban en su período reproductivo, en condiciones sanitarias aceptables aunque presentaban ataques de crisomélidos y del virus del mosaico. En una evaluación de campo que incluía los patios de las casas, en octubre de 1993, los componentes principales del sistema eran maíz, ajonjolí, yuca, fríjol criollo y algunas hortalizas como col y berenjena (Cuadro 3). La situación de Comején es similar a la de otra comunidad indígena (Bajo Grande) donde se repitió el programa. Los resultados indicaron que los componentes principales del sistema de producción son la yuca, el maíz y el ajonjolí; siguen en importancia el fríjol criollo, la habichuela y las hortalizas, mientras que el fríjol carauta es un componente marginal. Por razones económicas y culturales, el maíz y la yuca son la base de la alimentación de estas comunidades; se explica en parte la presencia del ajonjolí (Sesamun indicum) por la demanda y buenos precios que tiene en los mercados regionales, así como por su tolerancia a las sequías de fin de año. Algo similar ocurre con el fríjol criollo (Vigna unguiculata) que, además de su precocidad (60 días hasta la cosecha), no requiere de tutores. La habichuela (Vigna sesquipedalis) tiene una producción alta, se consume como fruto tierno y tiene demanda en los mercados regionales. La carauta, a pesar de ser conocida y aceptada, no se ha convertido en un componente significativo en los sistemas tradicionales de producción y de consumo de estas comunidades por las siguientes razones: hay otras leguminosas competitivas de mayor demanda regional, el fríjol carauta requiere de tutores, tiene un período vegetativo largo y no tiene demanda en los mercados locales. Esta especie entra en el conocido círculo vicioso de que una vez que un cultivo ha sido abandonado, la escasa producción y el consumo marginal subsecuente dificultan su reinserción en los sistemas tradicionales de producción. Plant Genetic Resources Newsletter, 2000, No. 123 27 Conclusiones • En muchas zonas campesinas de la Costa Caribe de Colombia se mantiene, como cultivo marginal, el fríjol carauta o zaragoza; sin embargo, su proyección hacia los mercados de las grandes ciudades de la región es escasa. • Hay una gran variedad de germoplasma de este fríjol y en él predominan los tipos sieva. El contenido de compuestos generadores de HCN en los materiales colectados, excepto en el genotipo Unicor 6 (626320), no sobrepasan el nivel de 100 ppm considerado tóxico para consumo humano. Por consiguiente, no es el contenido de HCN de las semillas el factor que ha influido en la posición marginal que ocupa hoy el cultivo. • En un experimento realizado en la vereda Comején del Resguardo Indígena de San Andrés, Córdoba, Colombia, en donde se repartió semilla y se hizo una campaña de fomento del cultivo entre hombres y mujeres, sólo el 20% de los productores continúa sembrando esta especie, después de 3 años de iniciada la campaña. • El bajo nivel de reinserción de este cultivo en la agricultura tradicional se debe a la escasa demanda de la carauta en los mercados de la zona y a la existencia de otras leguminosas competitivas (Vigna sp). Referencias Ballesteros, P.G. 1990. Evolución del fríjol lima (P. lunatus). Curso de evolución orgánica. Colegio de Posgraduados, Montecillos, Estado de México. 89 p. Barrera, M., G. Ballesteros y A. Torres. 1992. Caracterización agromorfológica de 12 accesiones de fríjol carauta (Phaseolus lunatus L.) en el valle del Sinú Medio. Tesis. Universidad de Córdoba. Montería, Colombia. Cooke, R.D. 1979. Enzymatic assay for determining the cyanide content of cassava and products. Cassava Information Center, Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. Debouck, D. 1979. Proyecto de recolección de germoplasma de Phaseolus en México CIAT/INIA. Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. Fernández, F., P. Gepts y M. López. 1985. Etapas del desarrollo de la planta de fríjol. En: Fríjol: Investigación y producción. Progrma de las Naciones Unidas para el Desarrollo (PNUD) y CIAT, Cali, Colombia. p. 61-78. Lyman, J.M. 1980. Adaptation and breeding studies on the lima bean (Phaseolus lunatus L.) as a food legume for Latin America. Tesis (Ph.D.). Cornell University, Ithaca, NY, E. U. 275 p. Maquet, A. 1989. Bean Program. En: CIAT Annual Report. CIAT, Cali, Colombia. (Multicopiado.) 28 Plant Genetic Resources Newsletter, 2000, No. 123 ARTICLE Plant Genetic Resources Newsletter, 2000, No. 123: 28 - 34 El conocimiento local y su contribución al trabajo de rescate, conservación y uso de las semillas de Phaseolus y Vigna en las vegas del Río Orinoco, Estado Guárico, Venezuela Angela Bolívar*, Marisol López, María D’Goveia y Margaret Gutiérrez Fondo Nacional de Investigaciones Agropecuarias-Centro Nacional de Investigaciones Agropecuarias, Apdo. Postal 4653, Maracay 2001, Venezuela. Email: [email protected]; [email protected]; [email protected] Resumen El conocimiento local y su contribución al trabajo de rescate, conservación y uso de las semillas de Phaseolus y Vigna en las vegas del Río Orinoco, Estado Guárico, Venezuela Con el propósito de colectar y conservar ex situ materiales de Phaseolus y Vigna, y también de caracterizarlos y aprender del conocimiento agrícola local de los productores, se utilizó el método de investigación de la entrevista etnográfica, diseñada para comprender los eventos observados haciendo énfasis en el análisis cualitativo etnográfico. Se tomaron datos a partir de una muestra de informantes clave (32 productores) localizados en las vegas de Parmana y Cabruta, extremo sur del Estado Guárico, en la margen izquierda del río Orinoco, en Venezuela. De la colecta se obtuvieron 21 materiales locales cuyos pasaportes fueron descritos partiendo de la categorización y del análisis de la entrevista etnográfica. Los resultados indican que los diversos materiales colectados provienen de un mejoramiento artesanal centrado en el conocimiento local de los productores de las vegas visitadas, los cuales, a través de sus experiencias y saberes, han contribuido a la conservación y uso de estos granos. Por otra parte, las condiciones de mediana a alta fertilidad de los suelos de las vegas bajo estudio, vistas a través de los análisis de suelos, es al parecer una de las causas de la permanencia en el tiempo de estos sistemas de producción de bajos insumos, adaptados al ambiente local y a la conservación del mismo. Los materiales colectados son, además, fuente primaria de recursos alimenticios para el mantenimiento del núcleo familiar y reducen además el área per cápita necesaria para la subsistencia; esta área está determinado por las inundaciones anuales del río Orinoco. Confieren también estos mataeriales características socioculturales muy particulares que deben considerarse a fin de mejorar la calidad de vida del productor y su familia. Résumé Les connaissances locales et leur contribution à la sauvegarde, à la conservation et à l’utilisation des semences de Phaseolus et de Vigna au Venezuela L’étude s’est appuyée sur des entretiens ethnographiques en vue de collecter et de conserver ex situ du matériel génétique de Phaseolus et de Vigna et de mieux connaître les pratiques agricoles locales. Les données ont été recueillies à partir d’un échantillon de 32 informateurs, situés dans les plaines de Parmana et de Cabruta et dans l’Etat de Guárico, sur la rive gauche de l’Orénoque, au Venezuela. Vingt et un échantillons provenant de cette collecte possèdent des données passeport basées sur la catégorisation et l’analyse des entretiens ethnographiques. Les résultats indiquent que les différents échantillons collectés sont le fruit de l’amélioration traditionnelle des cultures fondée sur la connaissance locale des plaines visitées. Les agriculteurs ont contribué par leurs connaissances à la conservation et à l’utilisation de ces légumineuses à graines. L’analyse des sols fait apparaître une fertilité moyenne à élevée, qui semble être l’une des raisons du maintien dans le temps de ces systèmes de production à faible apport d’intrants, adaptés à l’environnement local et à sa conservation. Le matériel collecté joue également un rôle fondamental dans l’alimentation des familles et réduit la superficie consacrée aux cultures de subsistance: cette zone est souvent déterminée par la crue annuelle de l’Orénoque. Ce matériel génétique possède des caractéristiques socioculturelles particulières qui devraient être prises en compte afin d’améliorer le bien-être des agriculteurs et de leurs familles. Summary The local knowledge and it contribution in the rescue, conservation and use of Phaseolus and Vigna seeds in margin areas of the Orinoco River, Cabruta, Parmana Guárico - Venezuela. The study used ethnographic interviews in order to collect and conserve ex situ Phaseolus and Vigna germplasm and to gain better knowledge of local agricultural practices. Data were collected from a sample of 32 key informants, located in the plains of Parmana and Cabruta and the extreme Guárico state, on the left margin of the Orinoco river, Venezuela. Twenty-one materials of this collection have passport data described based on the categorization and analysis of the ethnographic interviews. The results indicate that diverse materials collected are the result of traditional crop improvement based on local knowledge of the plains visited. Farmers have contributed through their local knowledge to the conservation and use of these grain legumes. The medium to high soil fertility as determined by soil analysis appears to be one of the reasons for the maintenance over time of these low-input production systems that are adapted to the local environment and its conservation. In addition, the collected materials are a primary source of food in the family diet and reduce the land area needed for subsistence: this area is often determined by the annual flooding of the Orinoco. This germplasm has particular sociocultural characteristics which should be taken into account in order to improve the welfare of farmers and their households. Keywords: Collecting, ethnographic interviews, germplasm, germplasm conservation, local knowledge Plant Genetic Resources Newsletter, 2000, No. 123 29 Introducción El conocimiento agrícola local es el que generan los agricultores, hombres y mujeres, a lo largo del tiempo; contiene información acerca de las preferencias y prácticas de los cultivos y se transmite de generación en generación mediante tradición oral. Este conocimiento representa una reserva importante de experiencias y saberes para la toma de decisiones ante los distintos problemas y retos que enfrenta una comunidad (Quiroz 1996). Sobre el conocimiento agrícola local se han realizados interesantes estudios, entre los cuales están los de Bentley (1989), Maundu (1990), Cruz (1990) y Mathias (1996); estos investigadores dejan ver en ellos la posibilidad de conservar los recursos fitogenéticos y mejorar la producción agrícola de una comunidad si se cruza la matriz de conocimiento local de los agricultores con el conocimiento agrícola de los investigadores; ambos se ayudarían y complementarían en la búsqueda de soluciones, tanto técnicas como de conservación de los recursos fitogenéticos. Uno de los principales insumos que se considera actualmente en los Centros de Investigación Agrícola es el conocimiento local; han adquirido experiencia en este campo el ICRISAT, el CIAT y el FONAIAP Lara y ya han incluido agricultores en sus programas de investigaciones. En Venezuela, las leguminosas comestibles son un componente básico en la dieta del productor y de su familia; por ello, considerar el conocimiento local de los agricultores, hombres y mujeres, sobre la producción, conservación y uso de las leguminosas es una estrategia clave que facilita el rescate de variedades locales y de materiales nativos; unas y otros podrán incorporarse luego en programas de mejoramiento genético por las vías de la conservación in situ y ex situ. En este trabajo se contempla la conservación ex situ; por tanto, las semillas colectadas en este estudio se mantendrán fuera de su hábitat original, en las instalaciones de los bancos de germoplasma para semillas del CENIAP (Centro Nacional de Investigación Agropecuaria) perteneciente al FONAIAP (Fondo Nacional de Investigaciones Agropecuarias de Venezuela). Al considerar la importancia que tiene el conocimiento agrícola local para colectar y conservar materiales, surgen limitaciones de índole metodológico cuando se trata de abordarlo. Para realizar este trabajo, se aplicaron los métodos cualitativos etnográficos propuesto por Martínez (1990). Para entender mejor el significado de la investigación etnográfica, consideremos algunas definiciones: • La etnografía, según Erikson (1973), es el estudio detallado de una sociedad o unidad social en particular; para Woods (1985), este término deriva de la antropología y significa la descripción del modo de vida de una raza o grupo de individuos; Martínez (1996) señala que el término etnográfico significa la descripción (‘graphos´) del estilo de vida de un grupo de personas habituados a vivir juntos (‘ethnos´) e indica que los estudios etnográficos, por sus características técnicas basadas en la observación, reciben otros nombres entre los cuales están los siguientes: método observacional participante, estudio de caso, método interaccionista simbólico, método fenomenológico, interpretativo o constructivista; sin embargo, la denominación más generalizada es la de métodos cualitativos. • Para Bogdan y Biklen (1982) la frase ‘metodología cualitativa´ se refiere, en su más amplio sentido, a la investigación que produce datos descriptivos, hablados o escritos y a la conducta observable. Dadas estas premisas, establecemos los objetivos del trabajo : - por una parte, colectar semillas de Phaseolus y Vigna y entregarlas al banco de germoplasma de FONAIAP para su caracterización científica, su evaluación, conservación y uso en programas de mejoramiento genético; - por otra parte, aprender del conocimiento local de los productores de las zonas sobre la conservación, producción y uso de las semillas de Phaseolus y Vigna para caracterizarlas. Antecedentes Características agroecológicas de las vegas del Río Orinoco El estudio realizado por Riera y Guerrero (1984) señala las siguientes características agroecológicas de las vegas del Río Orinoco. Tienen una superficie de 75,153 ha en la zona estudiada; representan el 2.1% de la superficie total de la Región Nororiental del Estado Guárico. Los suelos están dentro de la unidad agroecológica E-172. Fisiográficamente, la unidad se define como planicie de desborde del Río Orinoco. La precipitación promedio anual es de 1400 mm, que se concentra en seis meses en los que ocurre el 91% de la precipitación total anual; los picos están en julio y agosto. Los suelos predominantes son de los órdenes Aquepts y Fluvents, y las texturas más comunes son francolimosas (FL) y francoarcillolimosas (FAL). La fertilidad es considerada de media a alta; los niveles de disponibilidad de nutrimentos (en ppm) son de 15 a 20 para el fósforo, de 90 a 280 para el potasio y de 280 a 300 para el calcio. Estas características edafoclimáticas, entre otras, son las que antropólogos como Sanoja y Vargas (1978), consideran fundamentales para que los primeros grupos humanos asentados en la región (de 600 a 1000 años A.C.) lograran un alto grado de integración social y de cohesión cultural basadas en la agricultura, la pesca fluvial y la caza terrestre. Estos grupos debieron ser suficientes para establecer en la zona una población de cierta densidad que ha perdurado más de 2600 años, según los mismos autores. Materiales y métodos La metodología utilizada para desarrollar esta investigación se basa en la propuesta de Martínez (1990) sobre investigación cualitativa etnográfica, que consiste en la producción de estudios analítico-descriptivos de las costumbres, creencias, prácticas sociales, conocimientos y comportamiento de una cultura en particular. En estos estudios prevalece la observación participante, se centra la atención en el ambiente natural, se incorpora como co-investigadores a algunos sujetos escogidos y se evita la manipulación de variables por parte del investigador. Este trabajo contiene, como resultado, la categorización de los datos descriptivos hablados y la conducta observable del productor obtenida de una muestra intencional de informantes clave (32 productores) durante el período de preparación del terreno, de siembra y de cosecha en los meses de mayo, de 30 Plant Genetic Resources Newsletter, 2000, No. 123 octubre a noviembre de 1999 y de febrero del 2000. La metodología contempla los siguientes pasos: Delimitación de las zonas de colecta La zona delimitada correspondería a un caserío, un pueblo, el Estado o el país. La zona de colecta para este trabajo está en el eje Parmana-Cabruta localizado en el extremo sur del Estado Guárico, en la margen izquierda del río Orinoco, en Venezuela, entre las latitudes 7º 30’ y 8º30’ Norte y las longitudes 65º 30’ y 66º 30’ Oeste. Su superficie es de 75,153 ha pertenecientes a una misma unidad agroecológica. Entre las características físicas naturales más importante de la zona están las crecientes anuales del río Orinoco que regeneran periódicamente la capa vegetal de las riberas y de las islas del río. Uso actual. Estos suelos se usan en ganadería extensiva trashumante y para agricultura en las vegas del río; los principales cultivos son: caraota, frijol, algodón y patilla, que dan una cosecha al año a causa de la inundación a que están sometidos los suelos. Ubicación geográfica. Figuras 1 indica la ubicación de la zona estudiada. Fig.1. Atardecer en Las Vegas del Río Orinoco. ParmanaCabruta, Venezuela. Epoca del estudio Se eligieron los meses del año que, según los factores climáticos, garantizan la presencia de los elementos de estudio de las plantas (flor, fruto o semilla). Se realizaron 11 visitas en tres épocas distintas : a) 3 días en época de sequía (colecta de semilla), en el mes de mayo de 1999; b) 3 días en época de salida de lluvias (preparación del terreno y siembra), en el mes de octubre de 1999; c) 3 días en época de sequía (mantenimiento del cultivo), en el mes de noviembre de 1999; d) 2 días en época de sequía (cosecha ), en el mes de febrero del 2000. Permisología. Se pidió autorización para colectar muestras con fines científicos a: - Autoridades (cartas, entrevista) - Comunidades (cartas, reunión, taller) Instrumentos para recolectar información Para realizar este trabajo se escogieron estrategias de recolección de datos etnográficos, en especial, técnicas de triangulación de información. Estas permiten efectuar validaciones de información cruzada, recogiendo datos de diferentes fuentes (Patton 1987). En el presente caso, se emplearon en esta técnica tres instrumentos: la entrevista, la convivencia y la observación participante. Entrevista. Mediante la entrevista se motivó al productor, ayudándole a explorar, reconocer y aceptar sus propias vivencias. Se utilizó una guía que seguía temas elegidos previamente (aspectos sociales, tecnológicos y referentes a los materiales). En cuanto a los aspectos sociales, se recopiló información sobre el núcleo familiar: número de personas que laboran en la unidad de producción; organización del trabajo (familiar, asalariada fija, estacional); participación de la mujer en el trabajo productivo, reproductivo y comunitario; fuentes de conocimientos (escolaridad, textos, tradición oral, visitas técnicas); principales fuentes de ingreso; autoconsumo y relaciones con el mercado local. En relación con los aspectos tecnológicos, se abordaron tres etapas: preparación del terreno y siembra, mantenimiento del cultivo y cosecha. En relación con los materiales se trataron los temas siguientes: formas de conservación, selección de la semilla, usos, origen del material, nombre común, peso de la semilla, forma y color de la semilla). La entrevista se complementa con notas de campo de tipo memorando, grabaciones o filmaciones; en nuestro caso sólo se usaron las notas. Codificación. Cada entrevista se desarrolló en forma de relatos o historias, las cuales se codificaron con un número línea por línea; estas historias se leen todas las veces que sea necesario para luego seleccionar categorías comunes. Categorización e interpretación. Se dividieron los contenidos de la entrevista en temas similares y se agruparon según las características comunes, lo cual permitió seleccionar las siguientes categorías descriptivas: - selección y conservación de semillas, - formas de consumo, - origen de la semilla, - preparación y adecuación del suelo para la siembra, y - mantenimiento del cultivo. Convivencia. La convivencia es una técnica sencilla que nos permite interactuar con la comunidad. El objetivo primordial de esta técnica es lograr la empatía entre los investigadores y los productores. La convivencia con fines de investigación en recursos fitogenéticos logra que, en el plano cognoscitivo, la persona empática tome la perspectiva de la otra persona y se esfuerce, al hacerlo, por ver el mundo desde el punto de vista de esa persona. En el plano comunicativo, el individuo empático muestra comprensión e interés mediante claves verbales y no verbales. La convivencia se puede desarrollar mediante alguna actividad importante para la comunidad, bien sea a fiesta del santo de la localidad, las ferias o las faenas de trabajo. En este estudio se hizo en las faenas de trabajo (siembra y cosecha) y se acopió la información mientras se aprendía haciendo, observando y escuchando con mucha atención. En las convivencias se obtuvo la siguientes información: - lenguaje y tecnología local; - el papel de la mujer, Plant Genetic Resources Newsletter, 2000, No. 123 31 - formas de comunicación; - identificación de líderes ocultos o ya establecidos; - costumbres y creencias. Muestreo de suelos Con el propósito de precisar más el contexto agroecológico de las zonas de colecta, se hizo un recorrido por las áreas de estudio y su entorno. De este modo se logró obtener visualmente una apreciación de las condiciones descritas por Riera y Guerrero (1984) para estas unidades agroecológicas. Durante el recorrido se tomaron muestras de suelo con el fin de analizar la fertilidad de éste en cada una de las unidades de producción consideradas en la colecta. A fin de disminuir la variabilidad del suelo y obtener muestras representativas, se definieron unidades de muestreo (Ovalles 1992); cada unidad está representada por ½ ha o por 1 ha, considerando el tipo de manejo del suelo y sus características comunes, o sea, tipo de vegetación, color, posición fisiográfica y textura. En cada hectárea se tomaron de 20 a 30 muestras compuestas según la heterogeneidad del lote. Cada muestra compuesta consta de la mezcla de submuestras (entre 10 y 15). Las muestras se toman al azar siguiendo una trayectoria en zig-zag (Chririnos y Brito 1985). Las submuestras se mezclaron y de la mezcla se tomó, aproximadamente, 1 kg de suelo, el cual conformó la muestra compuesta que fue sometida a determinaciones físicas y químicas para conocer su fertilidad. Los resultados se interpretaron considerando criterios de deficiencia, suficiencia y exceso de nutrientes. Resultados y discusión Aplicabilidad de la metodología Cuando visitamos una comunidad rural con fines de investigación, observamos que posee un cúmulo de experiencias y agudos conocimientos sobre la utilización de diversos materiales de origen vegetal y animal, lo que les ha permitido sobrevivir en el tiempo. En estas comunidades hay valores, creencias y costumbres que permiten a sus habitantes, a pesar de las condiciones adversas del clima, de la infraestructura y de otras limitantes, resistir y permanecer en su lugar de origen. Otras comunidades rurales, por el contrario, se perciben indefensas y susceptibles en la medida en que son intervenidas por patrones de consumo, tecnologías y necesidades que vienen de fuera sin considerar su contexto sociocultural. En países en vías de desarrollo, esta situación causa preocupación porque es uno de los factores que llevan a hombres y mujeres, que se perciben indefensos, a trasladarse a las grandes ciudades dejando atrás un mundo de posibilidades y enfrentando otro de restricciones y discriminación social. Se desprende de aquí la necesidad de que las investigaciones sobre recursos genéticos presten tanta atención a los factores socioculturales que influyen en una comunidad como a la la utilización y conservación de esos recursos. De este modo se estaría contribuyendo a la conservación del germoplasma vegetal y animal en beneficio de las comunidades mismas y de la sociedad en general. En relación con los aspectos socioculturales, Ulloa (1995) señala que en las comunidades rurales hay un “simil de los bancos de germoplasma; es la memoria colectiva, donde están depositadas informaciones que vienen de generación en generación y que se mantienen en el tiempo gracias a un vehículo que se conoce como tradición oral. Los datos de este banco son codificados de manera peculiar y su acceso e interpretación requiere n, como en todo banco de información, de algunos criterios y destrezas y del dominio de ramas del conocimiento.” Consideramos, por tanto, que la investigación etnográfica es aplicable a este tipo de trabajo porque brinda la posibilidad de utilizar técnicas sencillas y de desarrollar destrezas para aprender de esa memoria colectiva y respetarla. Consideramos, además, que la etnografía, como rama fundamental del conocimiento de la antropología cultural y social, puede ayudar a los equipos que investigan en recursos fitogenéticos en la conservación y el uso del germoplasma vegetal a través de la participación justa y equitativa de los productores y productoras rurales. Se perciben, sin duda, limitaciones en cuanto a la sistematización de la información, que no es estándar, pero esto podría mejorar en la medida en que los equipos de investigación hagan uso de ella. Materiales colectados Se colectaron 21 materiales, a saber: 13 de Phaseolus vulgaris, 2 de Phaseolus lunatus, 5 de Vigna sp., y 1 de Cannavalia sp. Los materiales fueron entregados al personal encargado de realizar la caracterización científica completa de cada muestra y de hacer una comparación con estudios paralelos. El análisis y la discusión de los resultados quedaron restringidos aquí a la información suministrada por los productores y a la determinación, en el laboratorio, de dos características varietales: el peso de 100 semillas y la forma de la semilla. Los materiales presentados en el Cuadro 1 son comúnmente empleados por los productores para las siembras anuales y su origen es diverso: intercambio de productor a productor, compra en bodegas, compra en las algodoneras, conservada por familias de generación en generación como si fuera patrimonio familiar. Los criterios empleados por los productores para seleccionar las semillas son: buen tamaño y buen color, y no tener picaduras; para conservarlas, el método más común es dejarlas secar bien y luego guardarlas en ‘pipotes´, ‘tamboras´, botellas plásticas (Figura 2) y sacos; se les agrega a veces ceniza y se colocan en un lugar alto y apartado de los animales. Fig.2. Diversidad de materiales locales de Phaseolus vulgaris y Vigna sp Seleccinados y Conservados por los productores de la zona visitadas. 32 Plant Genetic Resources Newsletter, 2000, No. 123 Cuadro 1. Material de leguminosas colectado en las vegas del río Orinoco, Estado Guárico, Venezuela, en 1999 Entrada (no.) Origen del cultivar Nombre local Lugar de la colecta 99-056 99-057 99-058 99-059 De De De De Tapiramo, Tavaita Caraota blanca Vaina de acero, Media rama Tapiramo, Tavaita 99-060 99-061 De generación en generación De generación en generación, 10 años Compró a vendedor de grano Canavalia Fríjol negro Parmana, sector El Brisote Parmana Cedeño Sector Isla de López, Municipio Cedeño, Edo. Bolívar Sector Robo Pelao Sector Robo Pelao Compró a otro productor De generación en generación De generación en generación Compro en bodega Guardada de generación en generación Guardada por el productor hace 10 años Guardado por el productor Guardada por el productor Consiguió hace 3 años, se lo dio a otro productor Compró a otro productor Guardada por el productor Guardada por el productor Guardada por el productor Comprada a la algodonera Fríjol Vaina de acero Caraota blanca Caraota pintada Caraota negra Caraota blanca de Bejuco Sector Isla de López, Municipio Cedeño, Edo. Bolívar Vega la Guacamaya, Parmana Vega la Guacamaya Vega la Guacamaya Parmana Vega, Isla de López Caraota Pintada Sector El Burro Fríjol vaina de acero Fríjol Frijol Bejuco Parmana Sector El Burro Sector El Burro Caraota Caraota Frijol Caraota Caraota Parmana El Burro El Burro Isla El Baulito El Burro 99-062 99-063 99-064 99-065 99-066 99-067 99-068 99-069 99-070 99-071 99-072 99-073 99-074 99-075 99-076 generación generación generación generación en en en en generación generación generación generación Caraota pintada En el caso del cultivo de Phaseolus vulgaris ¾denominado caraota, solamente en Venezuela, según un vocablo autóctono de la lengua caribe (Voysest 1983)¾ se presentan diversos colores de semilla; los productores las clasifican por ello en caraotas negras, caraotas rojas, caraotas blancas y caraotas pintadas. Estas ultimas presentan distintas tonalidades que van del crema suave con manchas café rojizo al amarillo azufrado con manchas café rojizo. En el Cuadro 2 se muestran dos de las características determinadas en el laboratorio, o sea, la forma y el peso de 100 semillas, según los descriptores varietales del CIAT (1993). En los materiales de Phaseolus, la forma predominante es la de semilla arriñonada y recta en el lado del hilo (8); viene enseguida la forma ovoide (2). El peso varía de 14.12 g y 34.16 g por 100 semillas, lo que indica que se trata de semillas de medianas a pequeñas. Se consumen cuando el grano está seco; las de mayor preferencia en el consumo son las negras por su fácil y rápida cocción y por su sencilla preparación, pues su sabor no depende mucho de la cantidad o variedad de condimentos. Otra caraota preferida por los consumidores es la pintada; sin embargo, requiere de más preparación, o sea, cambio de varias aguas de cocción para eliminar el sabor amargo así como mayor cantidad y variedad de condimentos. En los dos materiales de Phaseolus lunatus, llamado comúnmente frijol tapiramo, se identificó un solo color crema oscuro con manchas café oscuro, con granos de forma arriñonada y ovoide, con un peso promedio de 32.29 g, de tamaño grande. Este grano se consume seco y es más exigente en la preparación y sazón; sus hojas se usan con fines medicinales. El material de Cannavalia sp. es la semilla de mayor tamaño con un peso de 64. 37 g, es de color blanco y de forma arriñonada y recta en el lado del hilo(8). Este material se usa comúnmente en negra blanca roja negra la zona del estudio para la alimentación del ganado y como abono verde. El material Vigna unguiculata es comúnmente denominado por los productores de la zona fríjol vaina de acero, fríjol media rama y fríjol bejuco; el color del grano varía de café rojizo claro a café oscuro. Las formas que predominan son la pequeña casi cuadrada (4), la ovoide (2) y la arriñonada (8). El peso de estos granos está entre 9.79 y 17.62 g, lo que indica que son los materiales más pequeños de la colecta. Según información de los productores, este es el grano que más se consume tanto en la zona estudiada como en el Estado Guárico, en sopa o acompañado, según la disponibilidad de recursos, de otros alimentos como plátano, pescado o carne seca. Otra forma de preparación es la mezcla de fríjol con arroz, lo que hace un plato típico de la región denominado “palo a pique”. Este grano se consume más que la caraota, por las siguientes razones: - como la caraota, es fácil de preparar y su sabor es también especial pues no requiere de la cantidad y variedad de condimentos que exigen otros granos; - el cultivo de la caraota es muy delicado y exigente mientras que el fríjol bejuco es más suave, su cultivo no exige muchos cuidados y es más resistente a plagas y enfermedades; - el fríjol bejuco se adapta a cualquier condición de clima y suelo por lo que se puede producir tanto para el mercado como para la familia; - en cuanto al valor nutritivo, los productores de la zona consideran el fríjol bejuco equivalente a la carne para la fuerza de trabajo. Esto indica que los criterios con que los productores de la zona de colecta eligen, para la siembra y el consumo, un material Plant Genetic Resources Newsletter, 2000, No. 123 33 como el fríjol bejuco, tiene una lógica que merece atención y podría interesar a los fitomejoradores para incluirla en sus proyectos de investigación. En relación con las prácticas agronómicas, se observó la variación de las distancias de siembra según el cultivo; las prácticas más comunes están centradas en la preparación del terreno. Los productores, al bajar las aguas del río Orinoco desde el mes de septiembre, comienzan las labores de preparación haciendo una limpieza del terreno, que consiste en eliminar las malezas con machete o herbicida o mediante la quema; hecho esto, siembran el fríjol. En algunos casos, todas las labores se realizan el mismo día y en otros se siembra de dos a tres días después de desmalezar, sobre terreno plano que va desde ½ ha hasta 4 ha o más. La siembra tiene dos modalidades: asocian el fríjol con otros cultivos, como el algodón o el maíz, o en monocultivo. La práctica más común es ‘a coa´, es decir, el agricultor abre, con una vara larga, el sitio en el suelo para la semilla y coloca en él de 4 a 5 semillas. En la siembra de la caraota se observaron distancias de hasta 30 cm entre plantas y 70 cm entre hileras (calles). En el caso de la caraota pintada, las distancia son de 1 m entre plantas y 3 m entre calles. Ninguno de los productores entrevistados manifestó que aplicaba fertilizantes y sólo se refirieron al mantenimiento, que consiste en observar el cultivo durante todo el ciclo para detectar un ataque de plagas o enfermedades, y controlar las malezas cuando lo creen necesario; así transcurren los 4 meses del cultivo y luego proceden a cosechar. Respecto a las características socioculturales y económicas de los productores y productoras de fríjol, el cultivo de estos granos representa una estrategia de seguridad para la familia puesto que su producción garantiza el consumo familiar abastecido durante todo el año y también el ingreso que entra por la venta de excedente para el mercado local. Se observó que en el grupo familiar los hijos o familiares cercanos son la principal fuente de mano de obra; la siguen los contratos temporales. Lasa mujeres juegan un papel determinante tanto en su labor reproductiva (mantenimiento del hogar, preparación de alimentos, cuidado de los niños) como en el trabajo productivo; se observó que las mujeres hacen labores de siembra, y algunos productores manifiestan que son más cuidadosas y dedicadas en estos trabajos. En general, la producción de granos de la zona es manejada generalmente por los hombres ya sea con mano de obra familiar, contratada o de otra modalidad, según sus necesidades. Respecto a la comercialización de los granos, se observó que suelen venderse a intermediarios que llegan a la zona y fijan el precio y la cantidad que compran. Esta situación preocupa a los productores, quienes manifestaron tener serias dificultades para vender sus cosechas pues consideran no que no reciben un precio justo. Los análisis del suelo de la zona de colecta (Cuadro 3) indican condiciones de fertilidad de intermedia a alta. El fósforo y el calcio disponibles se encuentran en un nivel de medio a alto; las principales limitantes son los bajos niveles de potasio y la reacción del suelo, porque se encontró un pH bajo que refleja una acidez de moderada a alta. Las variables edafológicas señaladas en el Cuadro 2 han definido, durante muchos años, el uso dado a las vegas visitadas. Si extrapolamos los estudios antropológicos de Sanoja y Vargas (1978) a la situación actual, encontramos que muchos cultivos que en el pasado eran las principales fuentes alimenticias de los grupos indígenas, como la yuca, el maíz, la ahuyama y los frijoles, hoy continúan cultivándose con prácticas adaptadas al ambiente local y que aun hoy contribuyen a preservarlo. Las observaciones de campo indican también que el conocimiento local de los productores de las vegas visitadas se refleja en la habilidad y destreza de las prácticas agrícolas desarrolladas bajo circunstancias muy particulares. Estas prácticas obedecen a las características físiconaturales antes Cuadro 2. Materiales de leguminosas colectados en las vegas del río Orinoco, Estado Guárico, Venezuela, en 1999 Nombre local Entrada (no.) Peso de 100 semillas (g) Formas Caraota blanca Vaina de acero, Media rama Tapiramo, Tavaita Canavalia Frijol negro Caraota pintada Frijol vaina de acero Caraota Blanca Caraota pintada Caraota negra Caraota blanca de bejuco Caraota pintada Fríjol vaina de acero Fríjol Fríjol bejuco Caraota negra Caraota blanca Fríjol Caraota roja Caraota negra 99-057 99-058 99-059 99-060 99-061 99-062 99-063 99-064 99-065 99-066 99-067 99-068 99-069 99-070 99-071 99-072 99-073 99-074 99-075 99-076 26.04 13.29 32.70 64.37 14.12 23.12 13.08 34.16 27.93 20.90 27.48 16.90 19.52 15.70 17.62 19.78 30.23 9.79 23.69 31.53 (2) Ovoide (4) Pequeña, casi cuadrada (2) Ovoide (8) Arriñonada, recta en el lado del hilo (8) Arriñonada, recta en el lado del hilo (8) Arriñonada, recta en el lado del hilo (4) Pequeña, casi cuadrada (8) Arriñonada, recta en el lado del hilo (8) Arriñonada, recta en el lado del hilo (8) Arriñonada, recta en el lado hilo. (2) Ovoide (8) Arriñonada, recta en el lado del hilo (8) Arriñonada, recta en el lado del hilo (4) Pequeña, casi cuadrada (8) Arriñonada, recta en el lado del hilo (2) Ovoide (2) Ovoide (2) Ovoide (8) Aarriñonada, recta en el lado del hilo (2) Ovoide 34 Plant Genetic Resources Newsletter, 2000, No. 123 Cuadro 3. Resultados de los análisis de suelos con fines de fertilidad hechos en la localidad de Parmana, en las vegas del Río Orinoco, en marzo de 1999 Variables Resultados Método de determinación† Textura P (ppm) K (ppm) Ca (ppm) Materia orgánica (%) pH (1:1.5) Franco limosa (FL) 11 - 25 40 - 70 338 - 500 1.0 - 1.6 4.5 - 5.0 Bouyoucos Olsen et al. 1954 Olsen et al. 1954 Morgan Combustión húmeda, Walkey and Black modificado Relación suelo:agua es 1:2.5 † Ver Manual de Métodos y Procedimientos de FONAIAP-CENIAP, Serie D, No.26, Capítulos 4.1 y 5.1, Maracary, Venezuela. descritas (Cuadro 3), las cuales determinan el aprovechamiento y uso de los suelos y aguas. Los productores conocen las ventajas de los suelos de las vegas para la producción de granos y otros cultivos a bajo costo, en comparación con otros suelos de la región. Esto justifica el significativo esfuerzo que cada año hacen estos agricultores cuando trasladan sus familias, casas y enseres al presentarse el desbordamiento del río Orinoco; pasado éste, vuelven años tras año. Conclusiones Los materiales colectados derivan de un mejoramiento artesanal centrado en el conocimiento local que tienen los agricultores, hombres y mujeres, de las vegas de Parmana y Cabruta; ellos, a través de sus experiencias y sus conocimientos, han contribuido a la conservación y uso de esos recursos. Las condiciones de fertilidad, de mediana a alta, que arrojan los análisis de suelos de la zona de colecta, pueden ser causa de la permanencia en el tiempo de estos sistemas de producción de bajos insumos. Por otra parte, los materiales que han sobrevivido, a pesar de la reacción ácida del suelo, se explicarían como un fenómeno de adaptación y selección natural. Los conocimientos locales de los productores de las vegas visitadas son fuente de valiosa información para colectar, caracterizar y conservar materiales en los trabajos de recursos fitogenéticos que se realicen. Ahora bien, el uso de dichos conocimientos no debe ser unidireccional, ya que se podría incurrir en una forma de expropiación o aprovechamiento indebido de los recursos. Es, por tanto, necesario que los centros de investigación asuman compromisos responsables con las comunidades rurales a fin de incorporar aspectos o estrategias que beneficien a la comunidad. Los materiales colectados son fuente primaria de recursos alimenticios para el mantenimiento del productor y su núcleo familiar, quienes utilizan el área per cápita necesaria para la subsistencia y el mercado local. Todo esto está determinado por las inundaciones anuales del río Orinoco, que le confieren características socioculturales muy particulares a la zona, las cuales deben considerarse a fin de mejorar la calidad de vida de los agricultores y sus familias. Referencias Bentley, J. 1990. Facts, fantasies and failures of farmer participation: Introduction to the symposium volume En : Memora del Simposio Participación del Pequeño Agricultor en la Investigación y Extensión Agrícola, celebrado en la Escuela Agrícola Panamericana de Zamorano, Honduras. CEIBA (Honduras) 31(2):7-27. Bogdan, R. and S. Biklen. 1982 Qualitative research for education: An introduction to theory and methods. Allyn y Bacen. p. 70-72. Chirinos, A.V. and J. Brito. 1985. Muestreo de suelos para diagnóstico de fertilidad. Serie E, No. 8-02. FONAIAP, Maracay. p. 18. Cruz, J. 1996. Saber local, poder y desarrollo humano sostenible. Bosques, Arboles y Comunidades Rurales (Costa Rica) 27:46-47. Erickson, F. 1979. Mere ethnography: Some problems in its use in educational practice. Anthropology and Education Quarterly:36-42. Gilabert de Brito, J., López I. de R. y R. Roberti. 1990. Análisis de suelos para diagnóstico de fertilidad. En: Manual de métodos y procedimientos de referencia. FONAIAP-ENIAP, Maracay. Serie D, No. 26. Martínez, M. 1996. Comportamiento humano: Nuevos métodos de investigación. 2ª. ed. Trillas, México DF. p. 199-207. Mathias, E. 1996. Marco para perfeccionar el uso de los conocimientos locales Bosques, Arboles y Comunidades Rurales (Costa Rica) 27:42-45. Maundu, P. 1996. Metodología para recolectar y compartir los conocimientos locales: Un estudio de caso. Bosques, Arboles y Comunidades Rurales (Costa Rica) 27:32-36. Muñoz, G., G. Giraldo y Fernández de Soto J. 1993. Descriptores varietales: Arroz, frijol, maíz, sorgo. Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. p. 75-78. Ovalles, F.A. 1992. Metodología para determinar la superficie representada por muestras tomadas con fines de fertilidad. Fondo Nacional de Investigaciones Agropecuarias (FONAIAP) e Instituto de Investigaciones Agrícolas Generales, Maracay, Venezuela. Serie E. 44 p. Patton, M. 1980. Qualitative evaluatíon methods. Sage, Beberly Hill, CA, E. U. p, 24. Quiroz, Consuelo. 1996. Taller sobre el proceso de la extensión agrícola y la perspectiva de género. Centro para la Agricultura Tropical Alternativa y el Desarrollo Integral (CATADI), Universidad de los Andes, Núcleo Rafael Rangel Trujillo, Mérida, Venezuela. (Mimeografiado.) Riera, J. y S. Guerrero. 1984. Diagnóstico agroecológico del nororiente de Guárico. En: Archivos de la Estación Experimental Valle de la Pascua, Guárico. FONAIAP, Venezuela. 184p. (Mimeografiado.) Sanoja, M. y I. Vargas. 1978. Antiguas formaciones y modos de producción venezolanos. Monte Avila Editores, Caracas, Venezuela. p. 106-117. Ulloa, L. 1996. Proyectos en las comunidades: ¿Construir escenarios de acción conjunta? Colección Cuadernos de Libre Opinión. Servicio de Información Mesoamericano sobre Agricultura Sostenible (SIMA), Managua, Nicaragua. p. 49. Voysest, O. 1983. Variedades de frijol en América Latina y su origen. Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. p. 85-87. Woods, P. 1985. Sociology, ethnography and teacher practice: Teacher and teacher education. p. 15 –21. Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 35 - 35 40 ARTICLE A network for the management of genetic resources of maize populations in France Jacques Dallard*, Philippe Noël, Brigitte Gouesnard and Armand Boyat Unité Mixte de Recherche “Diversité et Génome des Plantes Cultivées”, INRA Domaine de Melgueil, 34130 Mauguio, France. Tel: +33 4 67290617; Fax: +33 4 67293990; Email: [email protected] Summary Résumé Resumen French maize breeders have for a long time been aware of the need to save the genetic variability in maize populations. In the 1980s they decided to collaborate in order to study approximately 1315 populations and to equip themselves with the tools needed for the long-term conservation and dissemination of materials. A cooperative network was set up of French maize breeders, including public research and private companies, to allow the tasks of regeneration, conservation and distribution of materials to be shared between the members of the network and also with other partners. A common agreement, the “Charter for the management of maize genetic resources”, specifies the rights and obligations of the partners. Altogether 25 members regenerate 100 populations per year. Seeds are desiccated to 7% moisture content and packed in laminated aluminium-foil bags. Ten samples per population, containing 600 kernels each, are conserved in a coldroom at +4°C for distribution (user samples). Two other samples are stored for regeneration and safety purposes in a coldroom at –18°C. A 25-year conservation period is expected for the user samples. Unlike in other genebanks, in this cooperative network genetic resources are managed by maize professionals from their regeneration to their dispatch. Thanks to this collaborative network, efficient methods of regeneration and conservation, in line with the recommendations of IPGRI and the theoretical developments of population genetics, can be used. Les sélectionneurs français ont perçu depuis longtemps la nécessité de conserver la variabilité génétique des populations de maïs. Dans le cadre d’un programme qui a rassemblé et étudié environ 1315 populations, ils se sont dotés des équipements nécessaires à la conservation à long terme et à la distribution de ces ressources génétiques. Un réseau composé des unités de la recherche publique et des établissements privés de sélection permet un partage des tâches pour régénérer, conserver et distribuer le matériel aux membres du réseau et aussi à d’autres partenaires. Un accord : la “ Charte pour la gestion des ressources génétiques de maïs ”, précise les droits et les obligations de chaque membre. Actuellement, 25 partenaires régénèrent chaque année une centaine de populations. Les semences sont déshydratées à 7% d’humidité, puis conditionnées en sachets aluminium. Dix échantillons par population contenant 600 grains sont conservés dans une chambre froide à +4°C pour la distribution. On pense pouvoir les conserver pendant 25 ans. Deux autres échantillons sont conservés à – 18°C pour la régénération et pour la sécurité. Dans ce réseau coopératif, à la différence d’autres banques de gènes, tous les travaux, depuis le champ de régénération jusqu’à l’envoi aux utilisateurs, sont exécutés par des professionnels du maïs. Grâce à ce réseau coopératif, on utilise des méthodes efficaces de régénération et de conservation qui tiennent compte des recommandations de l’IPGRI et des approches théoriques de la génétique des populations. Los selectionadores franceses de maíz de han dado cuenta, hace tiempo, de la necesidad de conservar la variabilidad genética en poblaciones de maíz. En los años ochenta, en el marco de un programa que ha agrupado y estudió alrededor de 1350 poblaciones, se equiparon de los útiles necesarios para la conservación a largo plazo y la distribución de estos recursos genéticos. Una red, incluyendo la investigación pública y empresa privadas de selessión, permite repartir la tareas para regenerar, conservar y distribuir los materiales a los miembros de la red y también a otros socios. Un acuerdo común, la “ Carta para la gestión de los recursos genéticos del maíz “ especifica los derechos y obligaciones de cada socio. Actualmente, 25 miembros regeneran 4 poblaciones por año cada uno. Los semillas están deshydratadas a 7% de humedad y después condicionadas en bolsas de aluminio. 10 muestras de 600 granos por población están conservada en una cámara friá a +4° para distribuir. Dos muestras mas están conservadas a 18° para regeneración y para seguridad. Se espera un período de conservación de 25 años para las muestras de distribución. En esta red cooperativa, a diferencia de otros bancos de genes, todas las operaciones, desde el campo de regeneración hasta que envia a los usuarios, son ejecutados por professionales del maíz. Gracias a esta red de cooperación, se utilizán métodos eficaces de regeneración y de conservación, que tienenen cuenta las recomendaciones del IPGRI y los estudios teóricos de la genética de las poblaciones. A network for the management of genetic resources of maize populations in France Un réseau de gestion des ressources génétiques des populations de maïs en France Una red para la gestión de los recursos genéticos de las poblaciones de maíz en Francia Keywords: Ex situ conservation, genebank, landrace, regeneration, Zea mays L. Introduction Maize is a major crop in France, occupying 3.3 million ha of farmland; half of which is for silage production. The varied climatic conditions in France make it possible to crop early (grain or silage) to late (grain) hybrids. For 40 years, the annual gain in grain productivity has been 0.12 t ha-1 year-1, of which a major part is due to an important plant-breeding activity (AGPM 1994). In fact, increases in the annual production of maize are due to higher yields rather than increases in acreage. All cultivated maize varieties are now hybrids. The first development of maize hybrids began in France at the end of the 1950s, with the selection of the so-called first-cycle inbred lines. Early inbred lines, developed from European flint kernel populations, in combination with early dent American inbred lines, produced early hybrids suitable for European cultivation. The laboratories of the Institut National de la Recherche Agronomique (INRA) played a very important initial role in 36 Plant Genetic Resources Newsletter, 2000, No. 123 developing the first hybrids (INRA 200 in 1957, INRA 258 in 1958, INRA 260 in 1961). Thereafter, private and cooperative breeding companies further developed this activity by improving lines. This has resulted in continuous genetic progress and a flow of new varieties throughout northern Europe. In the 1980s a new interest emerged in landraces. The genetic basis of cultivated maize has narrowed as few genitors are used in hybrid development. Thus the F2 line, developed from the Lacaune population in about 1955, is still used and was present in 85% of the early and medium-early varieties sold in 1990 (Gallais et al. 1992). In 1983 public and private French maize breeders joined together to collect, maintain, characterize and evaluate maize landraces adapted to French conditions. With the financial support of the French Ministries of Scientific Research and Agriculture, the cooperative programme “Programme Populations Sources” (PPS) was formed under the leadership of Professor André Gallais and with the participation of six INRA laboratories1 and 16 private companies belonging to the PRO-MAIS2 association. Approximately 1300 populations of maize adapted to French conditions were included in the PPS. A description of the programme and its main results can be found in Gallais et al. (1992), Groupe Maïs DGAP-INRA, PROMAIS (1994) and Gallais and Monod (1998). Since 1993, the collection of maize population genetic resources has been managed through a maize network, with regeneration being carried out through an association of public and private maize breeders. The network’s regulations for the management and distribution of the genetic resources of maize are defined in a charter under the aegis of the Bureau des Ressources Génétiques (BRG)3, derived from the general charter for French genetic resources (http://www.brg.prd.fr/brg/ecrans/charte). This article presents the partners in the network, describes the technical and organizational aspects of the programme (regeneration, germination tests, medium- and long-term conservation) and discusses the advantages and disadvantages of such an organization. Guidelines for the distribution of material are also given. Maize populations The maize populations conserved are described in Table 1 according to their collection status and genetic type. All the French landraces still available and some French public synthetics are in the national collection. Although French landraces are well adapted to growing conditions they have not been grown as crops in France for about 30 years. In the 1950s and 1960s landraces were collected mainly by the INRA stations of Clermont-Ferrand, Saint-Martin-de-Hinx and Montpellier, The INRA units of Mons en Chaussée, Le Moulon, Lusignan, Clermont-Ferrand, Montpellier and Saint-Martin-de-Hinx. 2 Members of Pro-Maïs involved in PPS: CACBA, CARGILL (SEMENCES), CAUSSADE SEMENCES, CIBA-GEIGY, FRANCE CANADA SEMENCES, GIE EUROMAIS, ICI SEEDS, LIMAGRAIN, MAÏSADOUR, NICKERSON, NORTHRUP-KING SEMENCES, ORSEM, PIONEER FRANCE, RAGT, RUSTICA SEMENCES, SDME. 3 Bureau des Ressources Génétiques, 15 rue Claude Bernard, 75231 Paris cedex 05. http://www.brg.prd.fr/brg 1 mainly from the Pyrenean area, the Garonne valley, and Poitou, Bresse and Alsace, the areas where maize was traditionally grown. All these regions, which are characterized by rainy summers, are favourable for maize cultivation. Most French landraces are flint-type corn, of which 40% are white kernels. The genetic variability of all French landraces was studied by using morphological traits (Gouesnard et al. 1997). In addition to maize populations cultivated in France, other populations have been obtained through exchanges with national institutions. These are mostly early or medium-early maturing varieties, many of which originated in Eastern Europe and were chosen for their adaptability to French conditions Genepools derived from populations are also included in the collection. These have been formed by intercrossing 20 to 40 populations selected on the basis of utilization. Grain, forageyield performance, earliness and combining ability were taken into account. A large part of the pools were then crossed with elite materials in order to improve their agronomic traits. The network The network includes the PRO-MAÏS private companies and INRA stations distributed throughout France (see Fig. 1). PROMAIS (Association pour l’Etude et l’Amélioration du Maïs) is a private association, created in the 1960s, which gathers together all the seed companies carrying out maize breeding in France and working in the European market. The list of the 18 PROMAIS members for the year 2000 is given in Table 2. Its structure enables French private breeders and INRA scientists to combine resources and knowledge to carry out reTable 1. Origin and type of managed populations Collection status Landraces Synthetics National collection Network collection Total 270 60 648 918 Genepools Total – 330 267 74 985 327 74 1315 Table 2. Member companies of PRO-MAIS ADVANTA France ASGROW Monsanto SAS CARGILL Monsanto SAS CAUSSADE SEMENCES CEBECO SEMENCES CORN STATES INTERNATIONAL GOLDEN HARVEST - ZELDER LIMAGRAIN GENETICS MAÏSADOUR SEMENCES NICKERSON SEMENCES NORDSAAT France NOVARTIS SEEDS PAU SEMENCES PIONEER GENETIQUE R.A.G.T. SEMENCES RUSTICA PROGRAIN GENETIQUE S.D.M.E./K.W.S. France VERNEUIL RECHERCHES Plant Genetic Resources Newsletter, 2000, No. 123 37 data files. The network is experienced in maize experimentation and knowledgeable about maize variability and the breeding process. It has also gained experience in managing a genebank. Regeneration Scientific basis The main objective when regenerating germplasm is to avoid any loss of genetic diversity due to random genetic drift, subsequent inbreeding or loss of seed viability. However, this process has to be carried out under a programme constrained by limited funding. From studying population genetic theory Crossa (1989), Crossa and Vencovsky (1994) and Crossa et al. (1994) evolved practical methods of seed regeneration for maize or monoecious species. Theoretical developments are based on the concept of effective population size (Ne), i.e. that the size of a population is the size of a theoretical population with the same inbreeding coefficient, or the same allelic frequency variance, as that of the actual or hypothetical population under study. For a large mating population the effective population size can be defined as the number of progenitors contributing to the next generation (also called effective genitors). The number of effective genitors, sex ratio and variation in the number of offspring, influence effective population size (Crossa and Vencovsky Fig 1. Regeneration sites of maize landraces in France. Source: P. Ruaud 1994). These considerations have to be taken into account when defining the search to serve the common long-term interests of maize breed- number of conserved seeds, the mating design and the number ers and not just research for short-term profit. Projects are of seeds sampled on ears in order to constitute a seed set for proposed by the Genetic and Plant Breeding Department of conservation. INRA and managed by PRO-MAÏS and INRA together, under a To determine the number of seeds to be conserved for each general agreement for the regulation of research projects, paying accession, an analysis of genetic drift can be carried out considcareful attention to issues such as Intellectual Property Rights. ering the probability of keeping an allele for a locus. Based on a Most of the activities are developed with only some of the random mating population of infinite size and a Hardy members through a research clause included in the general agree- Weinberg equilibrium for independent loci, Crossa et al. (1993) ment. PPS, which operated between 1983 and 1993, was just such found that this probability was influenced much more by the a programme. Two long-term and compulsory activities are imple- sample size of parents and the frequencies of the rarest alleles mented by all members: experimentation of new inbred lines than by the number of alleles per locus. For example, the sample developed by INRA (GELI, Groupe d’Etude des Lignées INRA) size should be greater than 400 to preserve, with 95% probabiland regeneration of maize populations conserved in Montpellier. ity, four alleles per locus with the rarest at 1% frequency. Under The latter activity is the subject of this paper. the same conditions, a sample size of 80 would be sufficient for For this project the network is constituted by PRO-MAÏS a frequency of 5%. The loss of an allele has an incidence upon and the six INRA maize units; work is coordinated by the staff the reduction of heterozygosity. In general, the rate of change of the INRA maize unit at Montpellier. Besides the common task from x alleles to x-1 alleles (inbreeding rate) is F= x(x-1)/4Ne of regeneration, the team deals with seed conservation and (Kimura 1955). Frankel and Soul (1981) suggested that the rate distribution, and with documentation through catalogues and should not be higher than 1%. 38 Plant Genetic Resources Newsletter, 2000, No. 123 A full-sib mating design using plants as females or males but not both, ensures the control of the number of genitors and the equality of their sex ratio. Such a mating design maximizes the effective population size for a given number of progenitors. In this case, Ne=2Nt (Nt being the number of offspring in generation t), for a population in a Hardy Weinberg equilibrium with an equal contribution of parents and when all seeds give descendants (Crossa and Vencovsky 1994). In a mating design with random pollination and a controlled number of female progenitors the effective population size is lower than in full-sib mating design (Ne=4/3Nt with the same assumptions). For a limited number of progenitors the full-sib mating design is better than isolation field design. Selection during regeneration has contrasting effects: favourable when the mutation accumulation is considered and unfavourable when the evolution of population size is considered, expressed by the number of effective progenitors. Schoen et al. (1998) have investigated the impact of the regeneration procedure on mutation accumulation. They found that mutation numbers per genome increased significantly in sample sizes less than 75 or equalization of seed production by individual plants. With a number of viable seeds higher than the number of genitors, a selection step may occur during regeneration. Thus, the genetic load is maintained at an acceptable level. Implementation The following protocol of full-sib mating design is used in order to limit random genetic drift, preserve the increase of the inbreeding rate and limit mutation accumulation. For each population 500 to 600 kernels are sown at two planting dates, the second date at the emergence of the first. The two planting dates make crosses possible between plants of different earliness and favour panmixia. Both tassels and ears are bagged and pollination is carried out manually. Each plant is used once only as a female or a male but not both. The aim is to produce 200 ears per population. The conservation sample is a 600-kernel balanced sample composed by collecting 3 kernels from each of 200 ears. When less than 200 ears are obtained, more kernels are picked from each ear in order to maintain a 600-kernel sample. The accession is replanted the following season if less than 100 ears are obtained. Twelve samples are made up in this way and the remaining seeds are bulked. As each company has its own methods of working, the above compulsory protocol of cropping and managing the regeneration process was agreed on by the association in order to prevent discrepancies. In this way, all the partners use the same method. The standardized sets of seeds produced according to the agreed full-sib method are delivered to the conservation unit. Only the number of ears is allowed to fluctuate (between 100 to 200). Of course, this is laborious and time-consuming work with no immediate financial return. However, the awareness of members that the participation of each component of the network is needed for the long-term common good ensures that companies agree to this programme. During regeneration, sowing date, emergence rate, silking date, height, lodging, smut, stay-green and other stresses, if any, are recorded. All these data are then cross-referenced to a control hybrid present in the field and the effective number of used ears per balanced sample is recorded. Results For the past six years, population regeneration has made it possible to obtain 39% of populations with 100 to 150 ears, 35% with 150 to 200 and 26% with 200 ears. On average, from 550 sown seeds, 440 fertile plants and 163 full-sib ears are cropped. In the worst-case scenario, 385 plants and 100 fullsib ears are obtained. Since the seed sample is constituted by bulking three to six kernels per ear, it is possible that in the next regeneration plants from the same ear are crossed. However, as the probability of this happening is low: 0.003 and 0.008 for 200 and 100 ears respectively, it can be assumed that the risk is negligible. Below, one regeneration is considered as a step within a scheme with a constant population size so that Nt=Nt-1 (Crossa and Vencovsky 1994). We will assume that the mean allele number per locus is four. This number could be considered as an average situation between isozyme and RFLP loci (Dubreuil and Charcosset 1998). Three scenarios are considered: the best, the average and the worst, depending on the number of ears cropped (Table 3). Ne is given by the equation N e=N*2u/(2-u) (Crossa and Vencovsky 1994) where u is the ratio of the number of effective genitors on the number of progenitors or sown seeds (=550). Whatever the number of independent loci, any regeneration saves alleles at 5% frequency with 95% probability. However, only in the best-case scenario is a probability level of 1% frequency obtained. In any situation a number of potential genitor plants will be rejected: 48% in the worst-case scenario, 26% on average and 12% in the best case. Thus, selection against deleterious mutations always occurs. Table 3. Regeneration: probability of retaining four alleles per locus, according to sample size, for 550 germinated seeds and five loci Situation Number of ears Sample size U† Lower borderline Medium case Optimum case 100 163 200 200 326 400 0.36 0.60 0.73 † ratio of effective genitors: sown progenitors ‡ Effective population size Inbreeding rate Frequency of alleles Ne 241 471 632 F 1.2% 0.6% 0.5% 1% <90% 90% (b) § 95% (b) § (a) loci number <5 § (b): for 1 locus 3% 95% (a)‡ 95% 95% 5% 95% 95% 95% Plant Genetic Resources Newsletter, 2000, No. 123 39 Seed processing When a sample is added to the long-term genebank collection, the quality of seeds, including both their genetic and physical characteristics, must be checked. To do this, the following operations are carried out: sampling, check of purity, check of germination rate, drying, packing and labelling. After harvesting, seed is dried to 12-15% moisture content by a conventional dryer at 40°C. The balanced samples are then made up and sent to the conservation unit. Here samples are visually compared with previous samples in order to identify any pollution or error. Scored data are investigated. Germination tests The germination tests are carried out on two occasions: (1) at the receipt of a population after regeneration on two replicates of 100 remnant bulked seeds and (2) on each population every 10 years by sequential tests on 50 seeds from a user sample. The methods and norms used for commercial seeds (ISTA rules) seem to be poorly adapted to populations because in general, genetic resources have low germination energy and a high rate of fungal infection. We now use the method described below. On an enclosed plastic tray (60 cm x 40 cm x 7 cm) grains are distributed between two blotting paper layers. This size tray makes it possible to lay out 400 grains with enough space between them. Distilled water is then added and the trays are put in a room under the following conditions: 12 hours at 25°C with light and 12 hours at 18°C in the dark. Relative humidity is always kept higher than 85%. The germination rate is established with the proportion of normal and delayed seedlings after seven days. A poor relationship was observed between the germination rate in the laboratory and the emergence rate in the field. For this reason, traits such as delayed seedlings and fungal infection are also taken into account. When the germination rate is lower than 90%, or the percentage of fungal-infected seeds is greater than 35%, the regeneration process is carried out again the following year. Annually, approximately 5% of the populations have to be regenerated again due to germination deficiency. Seed drying Studies have highlighted the predominant influence of moisture content on seed ageing (IPGRI 1985; Roberts 1989). Therefore, a significant effort was made to lower the moisture content of seeds and to keep them in waterproof cans. In the drying room a dehumidifier is used which uses the absorption properties of lithium chloride. Grain is packed into net bags and during the first stage (one month) the drier is maintained at +15°C and 15% RH. For the next month conditions are maintained at +20°C and 10% R.H; the grain moisture content is then near 7%. The drying time for drying maize grain is long compared with other seeds because of the high seed weight. Seed packing After drying, each unit of 600 kernels is packed in a laminated foil bag and immediately sealed and stored in the coldroom. The bag consists of four layers: an outer layer of 50 g/m2 paper, a layer of 12 g/m2 polyethylene, followed by a layer of 15 µm aluminium foil and an inner layer of 36 g/m2 polyethylene. The polyethylene provides the sealing properties and the aluminium provides a barrier to moisture. In this way the seeds are maintained at 7% moisture content. Conservation and stock management Ten bags constitute the medium-term user samples destined to be distributed and preserved in the coldroom at +4°C. Their conservation time is assumed to be around 25 years. Two bags are kept for long-term conservation. The first is stored in a domestic refrigerator at -20°C at Mauguio, the second in a hired commercial coldroom at -18°C. This should ensure conservation for approximately 50 years. Distribution of germplasm Requests for material by users should be made in writing giving the proposed use. All materials conserved are free and available to members of the network. For others, the national collection is only available on the basis of reciprocal exchange. The sole condition laid down is that users of the material are required to report the data they gather on the germplasm received. This allows us to improve our knowledge of the material and its adaptability to different environments. Information management The information is managed with an application built on an ACCESS package. This allows for the identification of populations, and the management of passport data and some primary data. It is also used for stock management, the management of annual regeneration and the distribution of material. Therefore, it is possible to trace back the dates, destination, nature and amount of germplasm distributed in previous years. Paper records are also kept. An Index Seminum, implemented by the Unité de Recherche de Génétique et Amélioration des Plantes, describes the germplasm in the national collection and is widely distributed. Discussion and conclusion A main feature of this network is that maize professionals, within the framework of the plant-breeding network, are responsible for implementing the management of the genetic resources and not genebank specialists (Lefort et al. 1997). Therefore, nobody works full time on this activity. The disadvantage is that in the past, some problems occurred due to the lack of specific equipment or to poor knowledge of conservation practices. The advantage is that network members are knowledgeable about maize and the use of genetic resources by breeders. One interesting aspect of this network is the implication for French maize breeders, all of whom are committed to the task of regeneration through the “Charte pour la gestion des ressources génétiques du maïs”. Thanks to the number of regenerators involved, an efficient, but highly time-consuming and expensive method can be used. This would not be possible if only one public unit was involved in the project. In addition, all breeders have the opportunity to handle genetic resource materials and are aware that they are participating in a collective investment. 40 Plant Genetic Resources Newsletter, 2000, No. 123 Thus they are encouraged to use genetic resources in their respective breeding programmes. From the regeneration point of view, the distribution of regeneration locations in varied latitudes and climates (from 43°60’N to 50°N) permits the regeneration of the maize population collection with a high degree of earliness, from 700 to 1100 Growing Degree Units to female flowering. The regeneration and conservation costs have been evaluated for French genetic resources (Burstin et al. 1997). For maize alone, the regeneration step, at around 600 Euros per regeneration or 24 Euros per population per year, is clearly more expensive than the conservation step at 8 Euros per population per year. Therefore, our strategy will be to space out the regeneration as much as possible, to keep seed on a long-term basis and to manage the collection in such a way as to provide enough seeds to respond to requests. To manage the collection of French maize landraces a core collection of 80 populations has been constituted. Based on morphological and passport data, sampling is done by following the MSTRAT method (Gouesnard et al. unpublished). A number of classes of variables is used as a diversity index to maximize the allelic richness. Sampling commenced with a small number of early maize populations used in the development of first-cycle inbred lines. The aim is to favour germplasm utilization and to lower conservation costs. In future we could preserve all the germplasm deep-frozen for the long term, while making the core collection easily available to breeders for both quality selection and quantity of seeds. Our knowledge of the genetic variability of the core collection has also been enhanced by studies on neutral polymorphism (RFLP and micro-satellites). References AGPM. 1994. Association Générale des Producteurs de Maïs. Le maïs. Septembre 1994. Burstin, J., M. Lefort, M. Mitteau, A. Sontot and J. Guiard. 1997. Towards the assessment of the cost of genebank management: conservation, regeneration and characterization. Plant Var. Seeds 10:163-172. Crossa, J., C.M. Hernandez, P. Bretting, S.A. Eberhart, and S. Taba. 1993. Statistical genetic considerations for maintaining germplasm collections. Theor. Appl. Genet. 86:673-678. Crossa, J. and R. Vencovsky. 1994. Implications of the variance effective population size on the genetic conservation of monoecious species. Theor. Appl. Genet. 89:936-42. Crossa, J. 1989. Methodologies for estimating the sample size required for genetic conservation of outbreeding crops. Theor. Appl. Genet. 77:153-161. Dubreuil, P. and A. Charcosset. 1998. Genetic diversity within and among maize populations: a comparison between isozyme and nuclear RFLP loci. Theor. Appl. Genet. 96: 577587. Frankel, O.H. and M.E. Soule. 1981. Conservation and evolution. Cambridge University Press, Cambridge, UK. Gallais, A., H. Duval, P. Garnier and A. Charcosset. 1992. Un exemple de gestion des ressources génétiques en vue de la sélection. Pp. 468-477 in Complexes d’espèces, flux de gènes et ressources génétiques des plantes. Colloque international, Paris, 8-10 janvier 1992. BRG, Paris, France. Gallais, A. and J.P. Monod. 1998. La gestion des ressources génétiques maïs en France: de leur caractérisation jusqu’aux premiers stades de leur valorisation. C.R. Acad. Agric. Fr., 1998, n°3, pp. 173-181. Séance du 6 mai 1998. Gouesnard, B., J. Dallard, A. Panouille and A. Boyat. 1997. Classification of French maize populations based on morphological traits. Agronomie 17:491-498. Groupe Mais DGAP-INRA, PROMAIS. 1994. Cooperative program for management and utilization of maize genetic resources. Meeting of EUCARPIA, 15-18 March 1994, Clermont-Ferrand, France. IPGRI. 1985. Handbook of seed technology for genebanks. IPGRI, Rome, Italy. Kimura, M. 1955. Random genetic drift in a multi-allelic locus. Evolution 9:419-435. Lefort, M., M. Chauvet, Y. Dattee, J. Guiard, M. Mitteau and A. Sontot. 1997. The French strategy for the management of plant genetic resources. Plant Var. Seeds 10:153-162. Roberts, E.H. 1989. Seed storage for genetic conservation. Plant Today 2:12-17. Schoen D.J., J.L. David and T.M. Bataillon. 1998. Deleterious mutation accumulation and the regeneration of genetic resources. Proc. Nat. Acad. Sci. USA 95:394-9. Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 41 - 41 45 ARTICLE Caracterización por cianogénesis de una colección de trébol blanco (Trifolium repens L.) en Pergamino, Argentina E.M. Pagano y B.S. Rosso* Estación Experimental Agropecuaria del INTA, C.C. 31, 2700-Pergamino, República Argentina. Email: [email protected] Resumen Caracterización por cianogénesis de una colección de trébol blanco (Trifolium repens L.) en Pergamino, Argentina La concentración de ácido cianhídrico es una característica del trébol blanco que varía entre poblaciones y entre las plantas dentro de una población, y cuya distribución resulta afectada por distintas fuerzas de selección, siendo la temperatura la de mayor importancia. Con el fin de utilizar este carácter en la descripción de una colección de esta especie, se calculó la frecuencia de plantas que presentan esta condición en 53 poblaciones de trébol blanco (Trifolium repens L.) naturalizadas, recolectadas en Argentina, y en 21 poblaciones introducidas. El porcentaje de plantas cianogénicas en las poblaciones colectadas tendió a ser alto. Sólo dos poblaciones presentaron una menor proporción de fenotipos cianogénicos (40%). La única correlación significativa encontrada fue con el carácter precocidad. La intensidad de la reacción indicó que la mayoría de las poblaciones colectadas presenta formas cianogénicas leves y moderadas, a diferencia de las introducciones. En éstas se exceptúan las de Australia, en las que se observó una alta frecuencia de formas acianogénicas. Résumé Summary La concentration d’acide cyanhydrique est une caractéristique du trèfle blanc qui montre des variations entre populations et aussi a l’intérieur des populations. La distribution de cet acide est affectée par plusieurs facteurs de sélection étant la température le plus important. Avec le but de se servir de ce caractère pou décrire une collection de cette espèce on a établie la fréquence de plantes qui montrent ce condition sur 53 populations de trèfle blanc (Trifolium repens L.) collecté dans Argentine, et 21 populations exotiques. Le pourcentage de plantes cyanogénétiques pour l’ensemble des populations collectés était haut. Seulement 2 populations montraient une proportion plus faible de phénotypes cyanogénétiques (40%). L’unique corrélation positive trouvée a été avec précocité. La classification selon l’intensité de la réaction a montré des formes cyanogénétiques peu importantes et modérées dans la plupart des populations. D’un autre côté, la plupart des populations exotiques a montrée une haute fréquence de formes acyanogénétiques, exception faite des australiennes. Cyanide production (CP) in white clover accessions varies among populations and among plants within populations. Several factors affect CP distribution and temperature is the most important. In order to use this character to describe a germplasm collection of this species, the frequency of cyanogenic plants was evaluated in 53 naturalized populations collected in Argentina and in 21 introduced populations. The percentage of cyanogenic plants was high in the naturalized populations. Only two populations showed a lower proportion (40%) of cyanogenic phenotypes. Earliness was the only variable showing significant correlation with cyanogenesis. Reaction intensity indicated that most naturalized populations had low and moderate scores compared to introduced populations, except those from Australia, which had a high frequency of acyanogenic populations. Caractérization cyanogénétique d’une collection de trèfle blanc (Trifolium repens L.) à Pergamino, Argentine Introducción Como ocurre en otras 2000 especies vegetales, en las poblaciones de trébol blanco (Trifolium repens L.) hay una proporción variable de individuos capaces de liberar ácido cianhídrico (HCN). El follaje de muchas plantas de trébol blanco libera HCN cuando sus hojas sufren daños y este proceso se denomina cianogénesis. El HCN resulta nocivo para la planta; por ello no está presente como tal, sino que se produce por la acción de una enzima hidrolítica (la beta-glucosidasa) que hidroliza un glucósido cianogénico y el final de esta reacción es la liberación de HCN. Estos sustratos cianogénicos (lotoaustralina y linamarina) están almacenados en la vacuola mientras que la(s) enzima(s) correspondiente(s) se ubican a menudo en la pared celular. Por esta razón, el HCN se produce únicamente cuando se destruyen las células, condición en que el material vegetal empieza a contener un compuesto tóxico. Si bien el rumiante dispone de mecanismos que permiten transformar el HCN, cuando la cantidad de ácido absorbida es muy alta, el mecanismo de desintoxicación se satura y el riesgo de enfermedad por Cyanogenic characterization of a white clover (Trifolium repens L.) collection in Pergamino, Argentina Key words: Characterization, collection, cyanogenesis, populations, Trifolium repens, white clover intoxicación es mucho mayor (Lehmann et al. 1991). La herencia de la cianogénesis en el trébol blanco es diploide (Corkill 1942) dando lugar a dos fenotipos: uno cianogénico, que depende genéticamente de la presencia de dos genes complementarios en estado de dominancia (fenotipo Ac-Li-), y otro acianogénico, que se da en tres categorías: a) ausencia de cianoglucósidos, b) ausencia de linamarasa, y c) ausencia de ambos (fenotipos ac-Li, Ac-li y ac-li). El nivel de actividad cianogénica varía entre plantas diferentes y hay evidencia de que la variación cuantitativa en el contenido del glucósido depende, en parte, de la condición heterocigota u homocigota de estos genes; por tanto, la condición Ac/ac y la Li/li tendría distinto efecto que Ac/Ac y Li/- y daría lugar a distintas cantidades de HCN liberado (Hughes 1991). Por otra parte, se ha encontrado que esa variación cuantitativa se debe parcialmente a la existencia de diferentes alelos Ac y Li, los cuales determinan distintos niveles de actividad enzimática y de contenido de glucósido (Hughes et al. 1984). 42 Plant Genetic Resources Newsletter, 2000, No. 123 El polimorfismo cianogénico del trébol blanco interesa a los mejoradores porque, según las primeras investigaciones, el rendimiento de forraje y la persistencia de la planta están asociados a niveles moderados de cianogénesis (Caradus y Williams 1989). El polimorfismo es, sin duda, de origen genético; ahora bien, aunque se investigó el mantenimiento de la variabilidad de la cianogénesis y el papel de las fuerzas selectivas que operan para que esto ocurra, el sistema no ha podido ser entendido, en realidad. Si bien las relaciones entre latitud, altitud y distribución de los genes ¾encontradas por Daday (1954a; 1954b) y confirmadas por otros autores como Caradus et al. (1990)¾ están bien establecidas, es decir, el porcentaje de cianogénesis disminuye con el incremento de la altura y la latitud, quedan sin resolver las relaciones entre otros factores ambientales y biológicos que determinan el patrón de esa distribución. Así pues, la cianogénesis se considera generalmente como una protección contra los herbívoros depredadores y contra los insectos perjudiciales. Si esta fuese la única presión de selección, todas las poblaciones de trébol blanco deberían ser cianogénicas. Ahora bien, muchas de esas poblaciones no liberan HCN o son una mezcla de genotipos. Algunos estudios demuestran que las formas acianogénicas pueden ser favorecidas bajo ciertas condiciones edáficas (Foulds y Grime 1972). Entre los estudios hechos para determinar ventajas comparativas, Noitsakis y Jacquard (1992), sugirieron que los fenotipos acianogénicos tienen mayor acumulación de biomasa y producen más flores por planta, lo que puede ser el resultado de una utilización más eficiente de la energía; esas plantas tendrían, por tanto, mejor comportamiento bajo la condición de pasturas polifíticas. En relación con la variación en contenido, Daday (1955) halló una correlación positiva entre las poblaciones que tenían mayor proporción de plantas cianogénicas, de un lado, y una reacción de picrato más intensa, del otro. Caradus et al. (1989) encontraron que el alto potencial de liberación de HCN estaba claramente asociado con cultivares en que es más frecuente el fenotipo cianogénico. Las poblaciones de trébol blanco son polimórficas en su propiedad cianogénica; esta característica es, por tanto, útil como marcador genético y ha sido considerada así en muchos trabajos. Hawkins (1959), por ejemplo, la utilizó para la clasificación e identificación de variedades de trébol blanco. La lista mundial de variedades de trébol también incluye este carácter en la descripción de éstas (Caradus 1986; Caradus y Woodfield 1997). Es, además, uno de los descriptores sugeridos por el IBPGR (1992) para el trébol blanco (Trifolium repens L.). Este estudio tenía los siguientes objetivos: (1) caracterizar poblaciones introducidas y naturalizadas de trébol blanco del banco de germoplasma de la EEA INTA Pergamino; (2) determinar, en las poblaciones colectadas en Argentina, las posibles asociaciones del polimorfismo cianogénico con caracteres morfofisiológicos y con aspectos ecológicos, según el sitio de recolección del material, y (3) considerar la utilización de esa característica en la identificación o en la clasificación de las accesiones argentinas de trébol blanco. Materiales y métodos Las 21 accesiones introducidas eran originarias de Costa Rica (PI 193164), Italia (Simone, PI 195532, 217444, 233813, 291837, 291838), Irán (PI 260984, 326144, 381049), Australia (Waverly, Haifa, PI 201214, 237926, 241460), Israel (PI 200372), Chile (PI 291826, 291827), Japón (Makibashiro) y Estados Unidos (MSRedF, MSLM). Como testigo se utilizó la población mejorada El Lucero MAG (Argentina). Los 53 materiales naturalizados eran originarios de las provincias de Buenos Aires (1,2 3, 21, 22, 23, 24, 34, 36, 37, 38, 39), Santa Fe (4, 5, 6, 7, 8, 9, 10, 11, 19, 20, 25, 26, 27, 28, 29, 30, 31, 32, 33, 40, 41, 42, 43, 49, 50, 51), Entre Ríos (12, 13, 14, 15, 16, 17, 18), Córdoba (52, 53), La Pampa (35), Chaco (46, 47, 48) y Formosa (44, 45), que comprenden una franja situada entre los 26º y los 38º de latitud S y de los 58º a los 63º de longitud O. Cada planta se analizó aplicando la prueba del papel de picrato (Pusey 1966) a la tercera hoja expandida contada desde el ápice en crecimiento activo. Se colocó igual cantidad de hojas (un peso equivalente) en varios tubos de ensayo, se agregaron 2 gotas de agua y se maceraron las hojas. Se añadieron luego 2 gotas de tolueno y se colocó un tapón de goma en cada tubo; del tapón pendía una tira de papel embebido en picrato de sodio. Se incubaron los tubos en la estufa a 40 °C durante 2 horas y se sometieron a observación. Cuando el resultado era positivo, había un cambio en el color del papel: del amarillo viraba a un tono que va del naranja suave al marrón. Las plantas que dan reacción positiva son las Ac /Li y la intensidad de la reacción se asocia con la cantidad de HCN liberado; se clasificaron, por tanto, las plantas en tres grupos: de reacción leve (color naranja), moderada (color rojizo) y alta (color marrón). Se evaluaron 20 plantas de cada material y se establecieron las proporciones de cada tipo de reacción. Para el análisis estadístico se utilizó el paquete SAS (SAS 1985). Se hizo un análisis de correlación del carácter estudiado con las siguientes variables: grosor de los estolones, hábito de crecimiento, largo y ancho del folíolo, largo del pecíolo y días a floración. Asimismo, mediante el análisis de componentes principales se determinó la influencia de este carácter en los componentes principales. Resultados y discusión La Figura 1 presenta la caracterización de la cianogénesis en la colección de accesiones introducidas. Los resultados de la evaluación de las poblaciones introducidas mostraron que, en la mayor parte de éstas, son poco frecuentes las plantas que tienen los dos genes complementarios en estado dominante (fenotipos cianogénicos). La tendencia que muestra el germoplasma analizado puede relacionarse con su lugar de origen ya que las introducciones provienen de regiones frías o de alta montaña. Los resultados indican que las poblaciones de Costa Rica, Chile, Estados Unidos, Italia, Irán y Japón presentan un rango de fenotipos cianogénicos que va de 0% a 40%. Las introducciones de Australia e Israel, por su parte, presentaron mayor frecuencia de fenotipos cianogénicos similares al germoplasma de Argentina; el porcentaje de liberación de HCN de las plantas de cada accesión estaba entre 75% y 100%. Plant Genetic Resources Newsletter, 2000, No. 123 43 No se detectó ninguna asociación significativa del carácter de cianogénesis con las variables morfológicas y fenólogicas estudiadas. Sin embargo, según Daday (1965) y Caradus et al. (1989), los fenotipos cianogénicos florecen más temprano y los acianogénicos producen mayor número de inflorescencias. En estudios previos realizados en la EEA INTA Pergamino, el cultivar Espanso, que es acianogénico, se comportó como de floración tardía pero muy escasa (Pagano et al. 1998). La floración es un carácter altamente dependiente del fotoperíodo y también de la vernalización; además, nuestras condiciones pueden diferir de las que predominan en las regiones de origen de las poblaciones introducidas. Estos dos hechos podrían considerarse como causa probable de la ausencia de asociación de los caracteres estudiados en dichas poblaciones. En el análisis de componentes principales, la cianogénesis fue el carácter de mayor importancia para definir el segundo componente principal; es, por tanto, de importancia en la clasificación del germoplasma caracterizado. Dado que la concentración del HCN liberado varía entre poblaciones y entre plantas dentro de una población, los fenotipos cianogénicos se clasificaron según su capacidad de liberación de HCN (Fig. 2); se encontró así una población de trébol blanco proveniente de Israel que tenía alto contenido de cianógenos, en especial el cultivar Waverley cuya producción de HCN es muy alta. En la colección de poblaciones naturalizadas de diferentes provincias argentinas se encontró una alta frecuencia de fenotipos cianogénicos (Fig. 3); algo similar se observó en el testigo, Lucero MAG, que es el cultivar más difundo en el país. La excepción fueron dos accesiones en las que la frecuencia de plantas que liberan HCN fue de 40%. Estas plantas correspondieron a una población colectada en la localidad de mayor altura (140 msnm) y a otra población colectada en una latitud mayor (37ºS). Esto coincide con lo expresado por muchos autores, ya que la frecuencia de los genotipos cianogénicos Fig. 2. Clasificación del contenido cianogénico de las poblaciones introducidas de trébol blanco. Fig. 3. Caracterización de la cianogenésis en las poblaciones naturalizadas de trébol blanco. Fig.1. Caracterización de la cianogénesis en las poblaciones introducidas de trébol blanco. disminuye con la altitud y con la latitud (Daday 1954a, 1954b; Ganders 1990; Caradus et al 1990). También en poblaciones de Canadá (alta latitud), Fraser (1989) encontró que sólo una minoría eran cianogénicos, variando el porcentaje del genotipo Ac/Li del 1.7% al 35%. Según Foulds y Grime (1972), la exposición a una severa sequía causa la muerte de los fenotipos con el gen Ac. En esta colecta se tomaron poblaciones provenientes de sitios que estaban sometidos a una prolongada sequía pero no se observó que la frecuencia de plantas acianogénicas en dichas poblaciones fuera alta. En cuanto a la correlación de la cianogénesis con los caracteres morfológicos y fenológicos en las poblaciones colectadas en Argentina, se encontró una asociación 44 Plant Genetic Resources Newsletter, 2000, No. 123 significativa entre la cianogénesis y el número de días hasta el 50% de floración (r = 0.36). Esta asociación no se ajustaría a lo que concluyen Caradus et al. (1989) quienes observaron, en una clasificación de 109 cultivares, que la tendencia de los cultivares altamente cianogénicos era la floración temprana pero con bajo número de inflorescencias. En los primeros trabajos hechos en Nueva Zelandia se encontró que las poblaciones cianogénicas eran de folíolos grandes, más productivas y más persistentes (Foy y Hyde 1937); ésta es también la tendencia de los nuevos cultivares neozelandeses, a excepción del cv. G. Kopu (Caradus et al. 1995). En Estados Unidos, en cambio, tanto los cultivares utilizados, que se clasificaron entre los de folíolo grande, como el germoplasma colectado han mostrado ser predominantemente acianogénicos (Crush y Caradus 1995; Pederson et al. 1996). En cambio, en este trabajo, si bien se observó una alta frecuencia de poblaciones de folíolos grandes, no se halló ninguna asociación de la cianogénesis con el tamaño de la hoja (en las introducidas, r = 0.20, ns; en las colectadas, r = 0.15, ns respecto al ancho del folíolo). Los resultados de clasificar sobre la base de la intensidad de la reacción de las plantas cianogénicas, en las poblaciones argentinas, tienden a presentar una liberación de HCN de baja a moderada. Esta característica ubica esas plantas como un germoplasma de interés, ya que una alta producción de HCN puede llegar a ser tóxica para los rumiantes; en algunos países se recomienda no emplear cultivares con ese carácter. Además, se debe señalar que, de acuerdo con la bibliografía consultada, una frecuencia alta de plantas que contienen los genes Ac-/Li(fenotipo cianogénico) y el modo de reacción intenso de ellas están fuertemente correlacionados (Caradus et al. 1989). Es necesario considerar que la presión de selección a que han sido sometidas las poblaciones naturalizadas debería ser diferente en los diversos sitios de colecta, en los que hay diferentes condiciones no sólo de clima y suelo sino también del entorno en que se halla cada población; éstas provienen, en efecto, de banquinas, parques y potreros naturales sometidos a distintas intensidades de pastoreo y allí han estado con diferentes especies acompañantes. Según los resultados obtenidos, esas situaciones no han tenido influencia en la generación de poblaciones que contrasten en el polimorfismo de la cianogenésis de esta colecta. Así pues, el predominio de los fenotipos cianogénicos puede deberse, en gran parte, al papel desempeñado por el macroambiente el cual, para el área explorada, va de templado a templado cálido, principalmente. Conclusiones Las poblaciones introducidas se caracterizaron por la variabilidad en sus propiedades cianogénicas. Se estableció, en efecto, que en ellas hay una alta frecuencia de formas acianogénicas que poenen en evidencia las características de su lugar de origen. Las poblaciones naturalizadas colectadas en la Argentina fueron todas cianogénicas con valores que variaron del 40% al 100%. Los valores más bajos correspondieron a sitios de latitud y altitud mayores. Las formas más frecuentes de reacción fueron la liberación de HCN leve o moderada. No pudo detectarse una asociación de la cianogénesis con los sitios de recolección que eran afectados por largas sequías. Las poblaciones naturalizadas parecen responder a las condiciones ambientales del área de colecta. No se halló tampoco asociación de la cianogénesis con caracteres morfológicos relacionados con aspectos agronómicos; sólo se determinó una correlación positiva con el número de días a floración en los ecotipos colectados. Según el análisis de componentes principales, la cianogénesis fue un carácter de importancia para la clasificación del germoplasma caracterizado. Agradecimientos Las autoras agradecen al Ing. Agr. Oscar Bertín por la crítica revisión de este manuscrito y al Consejo Regional Buenos Aires Norte por el apoyo financiero para la realización de la colecta de accesiones. Referencias Caradus, J.R., R. Hay R. and D. Woodfield. 1995. The positioning of white clover cultivars in New Zealand. Agronomy Society of New Zealand Special Publications, No. 11. Grassland Research and Practice Series 6:45-47. Caradus, J.R. and D.R. Woodfield. 1997. World checklist of white clover varieties. NZ J. Agric. Res. 40:115-206. Caradus, J.R. 1986. World checklist of white clover varieties. NZ J. Exp. Agric. 14:119-164. Caradus, J.R., M.B. Forde, S. Wewala and A.C. MacKay. 1990. Description and classification of a white clover (Trifolium repens L.) germplasm collection from southwest Europe. NZ J. Agric. Res. 33:367-375. Caradus, J.R., A.C. MacKay, D.R. Woodfield, J. van den Bosch and S. Wewala. 1989. Classification of a world collection of white clover cultivars. Euphytica 42:183-196. Caradus, J.R. and W. Williams. 1989. Breeding for legume persistence in New Zealand. Pp. 529-530 in Proceedings of a Trilateral Workshop, Hawai. American Society of Agronomy, Madison, Wisconsin. Corkill, L. 1942. Cyanogenesis in white clover (Trifolium repens L.): The inheritance of cyanogenesis. NZ J. Sci. Technol. 8(23):178-193. Crush, J. and J. Caradus. 1995. Cyanogenesis potential and iodine concentration in white clover (Trifolium repens L.) cultivars. NZ J. Agric. Res. 38:309-316. Daday, H. 1954a. Gene frequencies in wild populations of Trifolium repens L.; I: Distribution by latitude. Heredity 8:61-78. Daday, H. 1954b. Gene frequencies in wild populations of Trifolium repens L.; II: Distribution by altitude. Heredity 8: 377384. Daday, H. 1955. Cyanogenesis in strains of white clover. J. Brit. Grassl. Soc. 10:266-274. Daday, H. 1965. Gene frequencies in wild populations of Trifolium repens L.; IV: Mechanism of natural selection. Heredity 20:355-365. Foulds, W. and J. Grime. 1972. The response of cyanogenic and acyanogenic phenotypes of Trifolium repens to soil moisture supply. Heredity 28:181-187. Foy, N. and E. Hyde. 1937. Investigation of the reliable of the “Picrit acid test” for distinguishing strains of white clover in New Zealand. NZ J. Agric. 55:219-224. Fraser, J. 1989. Characteristics of naturalized populations of white clover (Trifolium repens L.) in Atlantic Canada. Can. J. Bot. 67:2297-2301. Ganders, F.R. 1990. Altitudinal clines for cyanogenesis in introduced populations of white clover near Vancouver, Canada. Heredity 64:387-390. Hawkins, R.P. 1959. Botanical characters for the classification and identification of varieties of white clover. J. Nat. Inst. Agric. Bot. 8:675-682. Plant Genetic Resources Newsletter, 2000, No. 123 45 Hughes, M.A. 1991. The cyanogenic polymorphism in Trifolium repens L. (white clover). Heredity 66:105-115. Hughes, M.A., J. Stirling and D. Collinge. 1984. The inheritance of cyanoglucoside content in Trifolium repens L. Biochem. Genetics 22:139-151. IBPGR (International Board for Plant Genetic Resources). 1992. Descriptors for white clover (Trifolium repens L.). IBPGR, Rome. Lehmann, J., E. Meister, A. Gutzwiller, F. Jans, J. Charles and J. Blum. 1991. Peut-on utiliser des varietés de trefle blanc (Trifolium repens L.) a forte teneur en acide cyanhydrique? Revue Suisse Agricole 23(2):107-112. Noitsakis, B. and P. Jacquard. 1992. Competition between cyanogenic and acyanogenic morphs of Trifolium repens. Theor. Appl. Genet. 83:443-450. Pagano, E.M., J.O. Scheneiter and P. Rimieri. Persistencia vegetativa de trébol blanco (Trifolium repens L.) en el norte de la Provincia de Buenos Aires. Rev. Tecnología Agropecuaria 3(7):15-18. Pederson, G., T. Fairbrother and S. Greene. 1996. Cyanogenesis and climatic relationships in U.S. white clover germplasm collection and core subset. Crop Sci. 36:427-433. Pusey, J.G. 1966. Cyanogenesis in Trifolium repens L. Pp. 99-104 in Teaching Genetics (C.D. Darlington and A.D. Bradshaw, eds.). R.U., Edinburgh y Londres. SAS Institute. 1989. SAS/STAT User’s Guide. Release 6. 3a ed. Cary, North Carolina, E.U. 46 Plant Genetic Resources Newsletter, 2000, No. 123 ARTICLE Plant Genetic Resources Newsletter, 2000, No. 123: 46 - 51 Conservation et valorisation des ressources génétiques fourragères et pastorales du Nord Tunisien M. Chakroun1* et M. Zouaghi2 Institut National de la Recherche Agronomique de Tunisie, Rue Hadi Karray, 2049, Ariana, Tunisie. Fax : 216-1-752-897. Email: [email protected] 2 Institut National Agronomique de Tunis, 43 Avenue Charles Nicole, 1002, Tunis, Tunisie. 1 Résumé Conservation et valorisation des ressources génétiques fourragères et pastorales du Nord Tunisien La Tunisie, à l’instar des pays du bassin méditerranéen, possède une grande richesse d’espèces spontanées fourragères et pastorales. Cependant, ces espèces naturelles sont restées, jusqu’à présent, peu étudiées et sous-exploitées. Seules quelques espèces fourragères spontanées et/ou cultivars traditionnels, ont été évalués et ont fait l’objet de collections souvent actives. Mais, la plupart des espèces n’ont pas encore franchi l’étape de l’observation générale, bien qu’elles aient déjà enrichi de nombreuses banques de gènes internationales et servi à développer de nombreux cultivars. De nombreuses missions de prospection ont permis la collecte de près de 2800 accessions appartenant à plus de 100 espèces. Cet effort d’exploration et de collecte des plantes autochtones fourragères et pastorales, déployé par l’ensemble des institutions d’enseignement et de recherche en agriculture, est la première étape de la mise en valeur des ressources génétiques locales. La conservation et l’utilisation de ces ressources phytogénétiques locales constituent aujourd’hui l’un des programmes prioritaires adoptés par les commissions de programmation de la recherche agronomique dans le cadre des actions de sauvegarde et de valorisation du patrimoine génétique fourrager et pastoral. Il repose sur l’évaluation, la sélection et le développement de cultivars tunisiens en vue de leur introduction sur le marché et de leur utilisation par les agriculteurs. Resumen Túnez, como cualquier otro país mediterráneo, dispone de una rica diversidad genética en especies forrajeras y herbáceas, pero estas especies naturales no se han estudiado ni se utilizan cabalmente. Pocas de ellas son evaluadas y conservadas. Otras se estudian insuficientemente, aunque se conservan en muchos bancos de germoplasma internacionales y a partir de ellas se han desarrollado diversos cultivares mejorados. Se han realizado numerosas misiones de exploración que han permitido recoger unas 2800 accesiones correspondientes a más de 100 especies. Esta actividad de exploración, a cargo de investigadores de los Institutos Nacionales de Investigación y Educación, es sólo el primer paso para desarrollar los recursos genéticos locales, cuya conservación y uso constituyen uno de los programas prioritarios adoptados por los Comités Nacionales de Planificación de la Investigación para la conservación y valorización de los recursos forrajeros y herbáceos. Este programa se proponía evaluar el material conservado e incorporarlo a los programas de mejoramiento de forrajes y pastos, desarrollando así nuevos cultivares para su uso por los agricultores. Summary Tunisia, like any other Mediterranean country has been recognized as rich source of genetic diversity for forage and pasture species. However, these natural species are no fully studied and used. Few forage and pasture species are evaluated and conserved. Others are inadequately studied while they were conserved in many international genebanks and from which a range of improved cultivars have been developed. Numerous exploration missions were carried out and led to the collecting of around 2800 accessions representing more than 100 species. This exploration effort, deployed by researchers at the National Research and Education Institutes, is only the first step in the development of local genetic resources. Today, the conservation and use of these local genetic resources constitute one of the priority programmes adopted by National Research Planning Committees representing the preservation and valorization of the forage and pasture resources. This programme aimed to evaluate and incorporate the conserved material into forage and pasture improvement programmes and thus to develop new cultivars that will be used by farmers. Key words: Collecting, conservation, evaluation, forage, genetic diversity, genetic resources, improvement programme, pasture, Tunisia Introduction La Tunisie présente une grande richesse d’espèces spontanées fourragères et pastorales propres à l’alimentation animale mais dont la valeur fourragère est mal connue. Déjà en 1911, GAGEY rapportait l’existence dans de nombreuses régions, de plusieurs espèces fourragères spontanées intéressantes appartenant aux genres Medicago (espèces annuelles et pérennes), Scorpiurus (vermiculatées), Lolium (rigidum), Trifolium (repens, hybridum, subterraneum, fragiferum), Boromus, Lotus, Hedysarum, Phalaris, et Dactylis qui servaient à alimenter les troupeaux (Lapeyronie 1978). Malgré les efforts des chercheurs, ces ressources génétiques fourragères et pastorales naturelles restèrent peu étudiées et sont encore sous-exploitées. Seules quelques espèces fourragères spontanées ou cultivars traditionnels, ont été évalués et ont fait l’objet de collections souvent actives. Pour d’autres, seules des observations générales ont été reportées, alors qu’elles ont servi à enrichir de nombreuses banques de gènes internationales et à développer de nombreux cultivars (Zouaghi 1989). Ainsi, le Catalogue australien indique l’existence de très nombreux cultivars de graminées ou légumineuses (fétuque élevée, ray-grass anglais, dactyle, phalaris, medics etc.) obtenus à la suite d’une simple évaluation des ressources génétiques introduites à partir de l’Afrique du Nord (Tunisie, Algérie, Libye et Maroc). La plupart de ces cultivars sont utilisés de nos jours au sud de l’Australie, particulièrement dans les régions où les Plant Genetic Resources Newsletter, 2000, No. 123 47 précipitations sont comprises entre 350 et 500 mm. C’est le cas de la fétuque élevée ‘Déméter’, du dactyle ‘Currie’ ou de Medicago truncatula ‘Jemalong’ (Oram 1991). La conservation et la valorisation des ressources génétiques fourragères et pastorales sont devenues urgentes. L’objet de cette étude est de présenter une synthèse sur l’état des cultures fourragères et des principales espèces pastorales, sur les institutions en charge de la conservation et de la valorisation des ressources génétiques fourragères et pastorales en Tunisie, l’inventaire des travaux de collecte et les menaces d’érosion génétique. Une présentation des programmes en cours et de leur organisation concluent ce rapport. Cultures fourragères et principales espèces pastorales En Tunisie, le développement de l’élevage, secteur prioritaire de production, repose en grande partie sur la disponibilité des ressources alimentaires constituées d’une part, par les fourrages cultivés, les résidus de récolte et les sous-produits agroindustriels (19% des besoins de l’ensemble des élevages), et d’autre part, par les parcours, les arbustes fourragers et les zones forestières (67-68% des besoins). Les aliments concentrés représentent 13% du total des besoins alimentaires des troupeaux. Parmi ces ressources, les fourrages et les parcours occupent une superficie importante mais la contribution des fourrages aux besoins du cheptel est faible et va en diminuant en raison de l’utilisation abusive des parcours et de la réduction des surfaces fourragères semées (Zouaghi 1998). L’extension des cultures fourragères et pastorales prévue par les plans de développement se concrétise difficilement et les rendements de ces cultures restent faibles. Une analyse de l’exploitation pastorale et des cultures fourragères pratiquées en Tunisie, a permis de constater la faible productivité des couverts végétaux des zones pastorales et le manque de diversité des cultures fourragères. De plus l’insuffisance de semences fourragères constitue encore un handicap à l’extension de ces cultures. Cultures fourragères Le secteur fourrager est basé essentiellement sur la culture de l’avoine pure (Avena sativa L.) et/ou de la vesce-avoine récoltée sous forme de foin. La luzerne cultivée (Medicago sativa L.) et le bersim (Trifolium alexandrinum) sont cultivés particulièrement dans les périmètres irrigués et les oasis. En culture pluviale, l’orge en vert (Hordeum vulgare) tend à se substituer à la vesceavoine dans les zones les plus arides ou plus salées. D’autres cultures fourragères telles que le sulla (Hedysarum coronarium) sont actuellement en cours d’extension avec plus ou moins de succès. Le trèfle souterrain (T. subterraneum), les Medicago annuels (Medicago spp.), malgré les programmes de développement dont ils ont fait l’objet, sont en régression. Cet échec est imputable à l’application d’un modèle de mise en valeur étranger (australien) qui a été difficilement accepté par les agriculteurs. Dans les périmètres irrigués, le ray-grass d’Italie (Lolium multiflorum) et les cultures dérobées d’été comme le maïs (Zea mays L.) et le sorgho fourrager (Sorghum sp.), sont en augmentation. Les cultures pérennes sont de plus en plus pratiquées dans le nord du pays, particulièrement le sulla. D’autres espèces telles que la fétuque élevée (Festuca arundinacea) et le ray-grass anglais (Lolium perenne) sont, pour l’instant, destinées uniquement à la création de prairies permanentes. Toutefois, la performance de ces cultures reste insuffisante, en raison des facteurs suivants : • la non-maîtrise des techniques d’installation, de conduite des cultures, de récolte et de conservation • l’inadaptation variétale des espèces les plus couramment cultivées • l’emploi de semences non certifiées concurrençant un secteur semencier tunisien peu encouragé • l’érosion et la perte de fertilité des sols aggravées par un travail du sol effectué parfois perpendiculairement aux courbes de niveaux. Principales espèces pastorales herbacées Les prairies du Nord ont été considérées, pendant longtemps, comme le réservoir fourrager naturel de la Tunisie. Ces zones naturelles ont été intensément défrichées au profit des cultures céréalières, arboricoles et, plus récemment, de prairies permanentes. Seule, la prairie à Hedysarum coronarium / Convolvulus tricolor située dans l’espace de la base aérienne de Bizerte restent à l’état naturel. Le potentiel pastoral de ces zones demeure important comme le montre l’amélioration pastorale réalisée à Sedjenane, où l’introduction d’espèces fourragères productives telles que le trèfle souterrain, la fétuque élevée et le ray-grass pérenne, a permis d’aménager 6 000 ha de prairies dans le cadre du projet d’amélioration des pâturages dans le nord-ouest tunisien (Jaritz 1982). Actuellement, les superficies aménagées ne dépassent pas 8 000 ha. Ces prairies, malgré des investissements importants, sont aujourd’hui fortement dégradées en raison de l’inadéquation des systèmes d’exploitation et de suivi. Elles sont à présent partiellement couvertes d’une végétation inexploitable par les animaux qui annonce le retour du maquis. D’autres prairies ont été converties en céréaliculture et en arboriculture, zone à faible ressource fourragère pour le cheptel. La végétation naturelle non défrichée dans le nord, se répartit sur trois types de pelouses (Thiault 1957; Lapeyronie 1982; Zouaghi 1989, 1995) : • la pelouse caractéristique des stations sèches sur sol à encroûtement calcaire (Plantago lagopus et Echium parviflorum ou Oryzopsis miliacea) • la pelouse caractéristique des zones humides à inondation passagère (Festuca elatior et Oenanthe globulosa) • la pelouse sur marnes caractérisée par Hedysarum coronarium et Convolvulus tricolor. Ces trois catégories de pelouses comportent des espèces pastorales dominantes susceptibles de régénérer des pâturages à productivité satisfaisante. L’augmentation des rendements passe par l’amélioration des techniques culturales, le respect des stades de récolte et l’utilisation des méthodes de conservation appropriées. Elle dépend surtout de l’amélioration génétique et de la création de variétés adaptées aux différentes conditions du milieu (sol, 48 Plant Genetic Resources Newsletter, 2000, No. 123 climat, parasites et autres). La création variétale est assujettie à la disponibilité en ressources génétiques locales intégrant les adaptations aux conditions du milieu. Dès lors, la conservation et la valorisation des ressources génétiques deviennent essentielles pour répondre aux besoins actuels et futurs du pays. Ressources génétiques fourragères et pastorales Institutions en charge de la conservation et de la valorisation des ressources génétiques fourragères et pastorales en Tunisie Le maintien de la diversité et la réussite des programmes d’amélioration de la productivité passent par la conservation et la valorisation des ressources génétiques locales. Plusieurs institutions tunisiennes sont en charge de cette étape : • l’institut National Agronomique de Tunisie (INAT) • l’institut National de la Recherche Agronomique de Tunisie (INRAT) • l’ecole Supérieure d’Agriculture du Kef (ESA Kef) • l’ecole Supérieure d’Agriculture de Mateur (ESA Mateur) • l’institut des Régions Arides de Médenine (IRA) • l’institut National de la Recherche Scientifique et Technologique de Tunisie (INRST) • la Faculté des Sciences de Tunis. Les activités des trois derniers instituts, ne relèvant pas du Ministère de l’Agriculture pour cette opération, ne font pas l’objet de cette étude. Inventaire des travaux Depuis la fin des années 60, des activités de collecte, de conservation et de valorisation des germoplasmes fourrager et pastoral sont menées par l’INAT et l’INRAT. Ainsi, à la suite de diverses prospections de graminées et de légumineuses pérennes, des collections actives ont été réunies et des travaux d’évaluation et de sélection ont abouti à des variétés-populations de fétuque élevée, de ray-grass anglais, de dactyle, d’Oryzopsis, de phalaris et de trèfles. Ces variétés se sont révélées supérieures aux matériels étrangers testés, en termes d’adaptation, de productivité et de persistance (Chakroun et al. 1994). Les variétés de fétuque élevée sont maintenues en parcelles isolées in situ à la station de Mornag pour la production de semences. Cependant, le manque de moyens de conservation a conduit à la perte de la plus grande partie du matériel collecté. Seule la collection de l’INAT a pu assurer une certaine continuité dans ses travaux. En 1976 et 1984, L’IPGRI (International Plant Genetic Resources Institute) a organisé, en collaboration avec certains Instituts Nationaux de Recherche, deux missions de prospection qui ont permis la collecte de plusieurs espèces de céréales, de légumineuses alimentaires et de plantes fourragères. En 1980, une autre mission, effectuée dans le cadre du Projet intégré (OEP), a concerné quelques espèces de légumineuses des genres Medicago, Hedysarum et Trifolium. Cette prospection a couvert le nord et le centre du pays et 41 accessions de Medicago, représentant 12 espèces ont été collectées. Mais, le manque de coordination entre les divers intervenants et l’insuffisance des moyens humains, matériels et financiers ont empêché ces travaux d’évaluation d’aboutir à des écotypes commerciaux. A l’INRAT, le laboratoire des Productions Fourragères s’est particulièrement intéressé, ces dernières années, à la collecte, la conservation (Tableau 1) et l’évaluation des ressources génétiques fourragères et pastorales. En 1992, lors d’une mission de prospection en collaboration avec l’Unité des Ressources Génétiques (GRU) de l’ICARDA, 377 accessions, représentant 49 espèces et 12 genres de légumineuses pastorales, ont été collectées dans le centre du pays sur 40 sites (Hassen et al. 1994). En 1994, une autre mission, effectuée en collaboration avec le GRU et le Centre for Legumes in Mediterranean Agriculture d’Australie (CLIMA), a permis la collecte de 894 accessions d’espèces de légumineuses fourragères et pastorales représentant 16 genres et 80 espèces. Ces collections sont stockées à l’INRAT (Zoghlami et Hassen, comm. pers.). En juin 1994, conformément à la Convention pour la préservation du patrimoine génétique des principales graminées pérennes fourragères et pastorales, signée par l’Institution de la Recherche et de l’Enseignement Superieur Agricoles (IRESA), le Victorian Department of Agriculture (Australie) et l’USDA, une prospection de 10 jours sur 57 sites a été réalisée en collaboration avec le Department of Agriculture (Australie) et le USAID (USA). Des semences de 93 populations des espèces suivantes ont été collectées : fétuque élevée (Festuca arundinacea, Schreb.), ray-grass anglais (Lolium perenne L.), dactyle (Dactylis glomerata, L.) et phalaris (Phalaris tuberosa L.) (Chakroun et al. 1995). Une dernière prospection, effectuée en collaboration avec l’ICARDA en mai 1995, a assuré la collecte de 44 accessions du genre Hedysarum et de leur rhizobium sur 42 sites du nord et du centre du pays. La collection de rhizobium est installée à l’ICARDA. Une partie de l’ensemble du matériel collecté est en cours d’évaluation multilocale conformément au descripteur international et devrait aboutir à la sélection d’écotypes adaptés aux conditions locales. A l’INAT, des travaux sur les ressources génétiques sont conduits depuis les années 60. Mais, en l’absence d’un accord préalable sur le devenir du matériel biologique à collecter, la collaboration avec les organismes internationaux n’a pu se concrétiser. Les collectes sont aujourd’hui organisées chaque année pour couvrir systématiquement l’ensemble du territoire et permettre la constitution d’une collection active évaluée à environ 1200 lots de semences appartenant à 103 espèces fourragères et pastorales originaires de différentes régions du pays (Tableau 1). Certaines de ces espèces considérées comme prioritaires sont conservées au froid et à –18°C, après déshydratation. Cette technique, appliquée depuis 1981, donne de bons résultats ; des lots collectés à cette époque ayant montré, en 1996, un excellent maintien du pouvoir germinatif. Actuellement, les collectes sont financées uniquement par les Programmes Nationaux Mobilisateurs (PNM) de Recherche et concernent : Hedysarum coronarium, H. carnosum, H. spinosissimum, Trifolium sp., Medicago spp., Lathyrus et Lupinus ainsi que d’autres espèces de graminées et en particulier la fétuque élevée (en collaboration avec le Laboratoire des Productions fourragères de l’INRAT). Pour ces espèces, des variétés sont en cours de production particulièrement pour le sulla (Hedysarum coronarium), et le bersim (Trifolium alexandrinum). Plant Genetic Resources Newsletter, 2000, No. 123 49 Tableau 1. Espèces et nombre d’accessions fourragères et pastorales des différentes collections INRAT INAT Genre Espèce Accession Medicago Vicia Trifolium Lathyrus Lupinus Hedysarum Anthyllis Astragalus Coronilla Hippocrepis Lotus Melilotus Scorpiurus Tetragonolobus Trigonella Pisum Festuca Lolium Dactylis Phalaris Avena Hordeum Agropyrum Tricosecale Oryzopsis Bromus Crucifères Autres Total 25 8 20 3 3 4 2 7 2 4 5 2 2 1 4 1 1 1 1 2 2 405 108 179 36 3 83 10 63 29 52 77 19 126 14 27 1 38 19 22 14 12 † ‡ § 1 3† 104 Espèce ESA Kef Accession Espèce Accession 15 6 14 4 4 3 110 40 130 80 35 231 12 4 3 64 10 12 2 6 3 10 4 8 1 2 5 1 2 2 1 30 25 65 8 10 16 150 5 2 3 13 3 3 2 4 2 6 1 30 2 2 4 32 ‡ 103 10 10 50 105 1218 2§ 44 2 159 1 4 1342 Ononus et Hymonocarpus Glycine, autres légumineuses et graminées. Lespediza et Sesbania. A l’ESA Kef, le travail sur les ressources génétiques, a débuté en 1993 avec l’établissement d’une collection basée sur l’échange de germoplasmes (Ben Youness, comm. pers.). L’ESA Kef dispose actuellement de 159 accessions représentant 44 espèces de légumineuses et de graminées (Tableau 1). • Menaces d’érosion génétique Depuis plusieurs années, les observations consignées par les collecteurs indiquent une érosion génétique du matériel naturel local. Lapeyronie (1978), résumant les travaux de Gagey (1911) signale que la flore dans les principales zones fourragères de la Tunisie était, au début du siècle, beaucoup plus variée que dans les années soixante. Actuellement, il est facile de constater qu’elle est encore beaucoup plus dégradée notamment dans la zone de Mateur - Mabtouha - Bizerte. Cette situation est attribuée à : • l’introduction de variétés européennes et américaines pour l’amélioration des rendements, ce qui a contribué à la dénaturation des variétés locales, particulièrement pour les espèces allogames telles que le sulla ou certains trèfles • la destruction de l’habitat naturel de nombreuses espèces, menacées de disparition en raison du développement de l’urbanisation et de l’utilisation des terres (drainage des zones humides et construction de barrages) • • la mécanisation intensive de l’agriculture et la réduction des terres de parcours au profit des cultures céréalières et arboricoles aggravées par les catastrophes naturelles dans les écosystèmes fragiles (en particulier sous bioclimats semi-aride et aride), comme ce fut le cas en Tunisie en 1969 l’utilisation intensive d’herbicides destructeurs de la flore messicole et surtout le surpâturage les inondations et l’érosion catastrophique de la couche arable du sol qui est le réservoir naturel des semences in situ (Zouaghi 1988). Les rapports de missions de prospection (Burton 1981; Graves 1985; Cunnigham 1994) ont mentionné que les germoplasmes fourragers et pastoraux sont soumis à une érosion génétique forte, due à une croissance démographique de la population, à une augmentation des zones de culture et à une dégradation rapide des terres provoquée par une utilisation inappropriée des techniques culturales modernes. La tâche actuelle est donc de préserver la variabilité génétique de notre patrimoine fourrager et pastoral et de le valoriser en assurant son intégration dans les programmes d’amélioration des plantes pour l’intérêt immédiat de nos agriculteurs et pour un développement durable. 50 Plant Genetic Resources Newsletter, 2000, No. 123 Esquisse d’une stratégie pour le développement et la valorisation du patrimoine génétique fourrager et pastoral • Incorporation du matériel génétique évalué dans les programmes d’amélioration afin de créer de nouveaux cultivars de plantes fourragères et pastorales. La conservation et l’utilisation des ressources génétiques fourragères et pastorales est l’un des programmes prioritaires définis par les commissions de programmation de la recherche («Grandes Cultures» et «Elevage et Pastoralisme»). Dans ce cadre, un programme a été développé par les laboratoires de production fourragère de l’INRAT, l’INAT, l’ESA Kef et l’ESA Mateur. Ce programme entre dans l’action «Sauvegarde et valorisation du patrimoine génétique fourrager et pastoral» et comprend deux thèmes : i) développement de germoplasmes adaptés de légumineuses fourragères et pastorales ; ii) évaluation et développement de quelques variétés-populations de graminées pérennes fourragères et pastorales. La flore naturelle de Tunisie, extrêmement riche en espèces spontanées propres à l’alimentation animale, est en train de subir une dégradation alarmante. La grande variation des conditions du milieu (sol, température, pluviosité, humidité etc.…) a entraîné l’existence, pour chaque espèce comestible, d’un grand nombre d’écotypes. Cette variabilité génétique constitue un matériel de choix pour la sélection et la création de variétés adaptées aux conditions diverses. Parmi toutes ces espèces, une dizaine doit retenir plus particulièrement l’attention en raison de leur large utilisation actuelle, de leur potentiel élevé de production, et de leur importance économique dans les zones humides, sub-humides et semi-arides supérieures (Zouaghi 1987). Les activités de conservation et de valorisation du patrimoine fourrager et pastoral local intéressent deux types d’espèces prioritaires : les légumineuses (et leur rhizobium), et les graminées. Parmi les légumineuses, on s’intéressera en particulier aux espèces Hedysarum, Vicia, Trifolium, Lupinus, Medicago et Lotus. Concernant les graminées, les espèces prioritaires sont : Avena sp., Festuca sp., Lolium perenne, Dactylis glomerata, et Phalaris sp. Les espèces Phalaris sp., Vicia, Trifolium fragiferum et Lupinus sont les plus menacées de disparition. Pratiques de terrain, moyens de conservation ex situ et techniques de laboratoire seront optimisés pour aboutir à des créations variétales susceptibles d’intéresser les agriculteurs. Les espèces retenues pour les travaux d’amélioration sont : • légumineuses fourragères : vesce, sulla, bersim et luzerne cultivée • légumineuses pastorales à resemis naturel (légumineuses annuelles) : trèfle (Trifolium subterrameum), lupin et médics (Medicago spp.) • graminées annuelles et pérennes : avoine, orge en vert, fétuque élevée, ray-grass pérenne, ray-grass annuel, Sudan grass et maïs fourrager. Plan d’action La conservation et la valorisation des ressources génétiques fourragères et pastorales sont assurées par l’INAT, l’INRAT, l’ESA Kef, l’IRA Médenine et, à un moindre degré, par l’ESA Mateur. Pour pallier le manque de coordination des travaux, effectués par des scientifiques de spécialités diverses, l’Equipe de recherche fourragère et pastorale, regroupant tous les chercheurs de la discipline, a instauré un accord de coordination volontaire (Réunion de Mateur 1994). Les moyens humains et matériels restent cependant insuffisants, avec une répartition irrégulière des compétences suivant les instituts et une pénurie en personnel de soutien. Néanmoins, une amélioration est en cours depuis l’inscription des recherches fourragères au premier plan des préoccupations officielles par le Conseil ministériel restreint de mars 1998. Les structures existantes devraient encourager les chercheurs de ce groupe à resserrer les liens entre les institutions responsables de la recherche et de la conservation des ressources phytogénétiques fourragères et pastorales. L’ampleur des travaux a amené l’Equipe de recherche à procéder à la répartition des thèmes prioritaires de recherche et à se préoccuper de la réactivation du fonctionnement des contrats programmes. Trois équipes de chercheurs, seront mises sur pied, chacune spécialisée dans un type d’espèces : légumineuses fourragères, légumineuses pastorales et graminées fourragères et pastorales. En outre, ces équipes s’intéresseront, progressivement et en fonction des financements, à la conservation et la valorisation d’espèces locales non prioritaires. Les missions de collecte seront planifiées en 5 phases : 1. Développement d’une stratégie de collecte et de l’itinéraire à suivre. 2. Collecte : moyens de déplacement, fiche d’information. 3. Conditionnement et conservation du matériel collecté. 4. Constitution d’une base de données reliant les différentes équipes à travers le réseau ‘intranet’ créé à l’IRESA. 5. Mise à disposition du matériel maintenu auprès des utilisateurs potentiels (sélectionneurs, physiologistes, autres banques de gènes...). Objectifs du programme • Poursuite des travaux de collecte des espèces fourragères et pastorales spontanées pour le maintien de la diversité génétique • Evaluation agronomique et fourragère du matériel biologique collecté et multiplication en absence de contamination pollinique • Conservation, à moyen et long terme, du matériel génétique à des fins d’amélioration variétale La réalisation des objectifs avancés dans ce programme de conservation et de valorisation des ressources génétiques fourragères et pastorales est subordonnée à la mise en application des étapes représentées dans la figure 1 et à l’obtention des moyens humains, matériels et financiers nécessaires. La conservation et la valorisation des ressources génétiques entre dans le cadre d’un travail pluridisciplinaire. L’ouverture de cette activité à d’autres domaines dépendra des objectifs et de l’importance économique du programme en question. L’exploration et la collecte des plantes autochtones fourragères et pastorales est le préalable au développement de ces ressources génétiques qui verra son aboutissement dans le développement de cultivars tunisiens commerciaux après évaluation et sélection. L’exploitation efficace de ces ressources génétiques exige une Plant Genetic Resources Newsletter, 2000, No. 123 51 concertation et une coopération entre les différentes institutions, renforcées par des moyens de travail supplémentaires et déjà initiées au sein de l’Equipe de Recherche Fourragère et Pastorale créée en 1994 à la réunion de Mateur. Remerciements Les auteurs tiennent à remercier Mme Ghrabi Ghammar Z., Melle Zoghlami A. et MM. Hassen H., Ben Youness M., et Ben Jeddi F. pour leur collaboration à la réalisation de ce travail. Références Anonyme. 1994. Orientations et programmes de recherche en production fourragère en Tunisie. Mateur, 16-17 mars 1994. Burton, J.C. 1981. Use of Rhizobium-leguminous plant association to increase forage and pasture production in Tunisia. Report on a survey and nodule collection trip through Tunisia. 27 March-21 April 1981. Chakroun, M., M.Y. Mezni et H. Seklani. 1994. Importance des graminées pérennes locales dans la diversification des productions fourragères. Journées nationales sur les acquis récents de la recherche agronomique. Hammamet, 2-4 déc 1994. Chakroun, M., M.Y. Mezni, P. Cunningham and W. Graves. 1995. Genetic resources collection of perennial pasture grasses in Tunisia. «Options Mediterranéennes», Proceedings of the meeting of the Mediterranian Working Group of the FAO/ CIHEAM Inter-Regional Research and Development Network on Pastures and Fodder Crops, Avignon (France), 29 May-2 June 1995.49-51. Hassen, H., A. Zoghlami et S. Sassi. 1994. Contribution à l’étude de quelques espèces spontanées de légumineuses pastorales en Tunisie centrale: Répartition géographique et relation avec le milieu environnement. Ann. de l’INRAT, 67 (1,2): 203-221. Jaritz, G. 1982. Amélioration des herbages et cultures fourragères dans le nord-ouest de la Tunisie : étude particulière des prairies de trèfles-graminées avec trifolium subterraneum. GTZ. Germany. Lapeyronie, A. 1982. Les productions fourragères mediterranéennes. Tome I: Généralités, caractères botaniques et biologiques. Techniques agricoles et productions méditerranéennes. G.P. Maisonneuve et Larose, Paris, France. McWilliams, J.L. 1980. Report on plant exploration and collection in Tunisia. May/June 1980. Oram, R.N. 1991. Register of Australian Herbage Plant Cultivars. 3 rd Edition. Australian Herbage Plant Registration Authority. Division of Plant Industry. CSIRO Publications, Melbourne, Australia. Thiault, M. 1957. Les pelouses de la Tunisie du Nord et leurs aptitudes pastorales. Ann. du Ser. Bot. et Agr. de Tunisie. 30: 165-170. Zouaghi, M. 1987. Production fourragère et pastorale en Tunisie. Identification des problèmes et besoins de recherche à long terme par grand secteurs de production. Programme de développement de la recherche agricole en Tunisie. Vol. 2: 194-227. ISNAR R27f. Zouaghi, M. 1989. Le patrimoine génétique fourrager et pastoral: ressources à préserver et à promouvoir. Pp. 107-115 in Constitution de Réseaux Thématiques de Recherche Agricole au Maghreb. Birouk, A., Ouhsine A. et Ameziane E. Eds, Actes du séminaire organisé à Rabat en décembre 1988, Réseau TRAM. ACCT. Zouaghi, M. 1995. Etude et aménagement à prévoir dans la zone des marais de l’Ichkeul. Rapport BCEOM sur l’aménagement du Parc National de l’Ichkeul. Fig. 1. Représentation schématique des principales activités liées à la conservation des ressources génétiques fourragères et pastorales. 52 Plant Genetic Resources Newsletter, 2000, No. 123 ARTICLE Plant Genetic Resources Newsletter, 2000, No. 123: 52 - 60 Resistance to powdery mildew in barley (Hordeum vulgare L.) landraces from Egypt Jerzy H. Czembor Plant Breeding and Genetics Department, Plant Breeding and Acclimatization Institute, Radzików-Warsaw, 05-870 Blonie, Poland. Tel: +48 22 7252611; Fax: +48 22 7254714; Email: [email protected] Summary Resistance to powdery mildew in barley (Hordeum vulgare L.) landraces from Egypt This study consisted of screening 135 barley landraces collected in Egypt for resistance to powdery mildew. The landraces originated from the collection of the International Center for Agricultural Research in the Dry Areas (ICARDA). Eight landraces (6%) showed powdery mildew resistance reactions and 11 single plant lines were selected. Three of these lines were tested in seedling stage with 17 differential isolates of powdery mildew and another eight lines with 23 differential isolates of powdery mildew. The isolates were chosen according to their virulence spectra observed on the Pallas isolines differential set. Distribution of reaction type indicated that 80% of all infection types observed could be classified as powdery mildew resistance (scores 0, 1 and 2). Line 441-1-1 showed resistance to all major powdery mildew virulence genes present in Europe. In nine lines (82%) the presence of unknown genes in combination with a specific one was detected. Two different resistance alleles Mlat and Mla7 were postulated to be present in the tested lines. The most common resistance allele in the tested lines was Mlat, which was present in nine tested lines. Among the three regions of Egypt from which the landraces originated those collected in Marsa Matrruh and north Sinai expressed resistance to powdery mildew. All landraces collected in As Sahra Ash Sharqiyah were susceptible to R303 isolate. The barley landraces discussed in this study will be of value in diversifying the genes resistant to powdery mildew used in barley breeding. Key words: Erysiphe graminis, germplasm, Hordeum vulgare, landraces, powdery mildew, resistance genes Résumé Résistance au blanc des races locales d’orge (Hordeum vulgare L.) provenant d’Egypte Cette étude a consisté à cribler 135 races locales d’orge collectées en Egypte en vue de tester leur résistance au blanc. Ces races locales provenaient de la collection du Centre international pour la recherche agricole dans les régions sèches (ICARDA). Huit variétés locales (6 %) ont résisté au blanc et 11 lignées dérivant d’une plante unique ont été sélectionnées. Trois de ces lignées ont été testées au stade plantule par 17 isolats différenciés de blanc et huit autres lignées par 23 isolats différenciés de blanc. Les isolats ont été choisis selon leur spectre de virulence observé sur la série différenciée d’iso-lignées de Pallas. La distribution du type de réaction indique que 80 % des types d’infection observés pouvaient être classés comme résistants au blanc (cotes: 0, 1 et 2). La lignée 441-1-1 a affiché une résistance à tous les principaux gènes de virulence du blanc présents en Europe. Chez neuf lignées (82%), on a détecté la présence de gènes inconnus associés à un gène spécifique. On a posé comme principe que deux différents allèles de résistance Mlat et Mla7 étaient présents chez les lignées testées. L’allèle de résistance le plus fréquent chez les lignées testées était Mlat, présent chez neuf lignées testées. Sur les trois régions d’Egypte d’où provenaient les variétés locales, celles récoltées à Marsa Matrruh et dans le nord du Sinaï se sont montrées résistantes au blanc. Toutes les races locales récoltées à As Sahra Ash Sharqiyah étaient sensibles à l’isolat R303. Les races locales d’orge examinées dans cette étude seront précieuses pour la diversification des gènes résistants au blanc utilisés dans les programmes d’amélioration de l’orge. Resumen Resistencia al mildiu pulverulento en las variedades locales egipcias de cebada (Hordeum vulgare L.) Este estudio consistió en seleccionar 135 variedades de cebada recogidas en Egipto para observar su resistencia al mildiu pulverulento. Las variedades procedían de la colección del Centro Internacional de Investigaciones Agronómicas en Zonas Áridas (ICARDA). Ocho de ellas (6%) tuvieron reacciones de resistencia al mildiu y se seleccionaron 11 líneas de plantas separadas. Tres de éstas se sometieron a prueba en su fase de plántulas con 17 cultivos aislados diferenciales de mildiu, y otras ocho líneas se sometieron a la misma prueba con 23 aislados diferenciales de mildiu. Los cultivos aislados se escogieron por sus espectros de virulencia observados en la serie diferencial de isolíneas Pallas. Los tipos de reacción indicaron que el 80% de todas las infecciones observadas podían clasificarse como resistencia al mildiu pulverulento (0, 1 y 2 puntos). La línea 441-1-1 mostró resistencia a todos los principales genes de virulencia de mildiu presentes en Europa. En nueve líneas (82%) se detectó la presencia de genes desconocidos en combinación con uno específico. Se dedujo la presencia en las líneas sometidas a prueba de dos alelos de resistencia diferentes Mlat y Mla7. El alelo de resistencia más común en esas líneas era Mlat, presente en nueve líneas. Entre las tres regiones de Egipto de las que procedían las variedades locales, las recogidas en Marsa Matrruh y Sinaí septentrional mostraron resistencia al mildiu pulverulento. Todas las variedades recogidas en As Sahra Ash Sharqiyah eran susceptibles al aislado R303. Las variedades de cebada aquí estudiadas serán valiosas para diversificar los genes resistentes al mildiu utilizados en la mejora genética de la cebada. Introduction Barley (Hordeum vulgare L.) is the fourth most important cereal crop in the world after wheat, maize and rice. Among African countries, barley is an important crop in Ethiopia, Eritrea and Sudan, and in North African countries such as Morocco, Tunisia, Algeria, Libya and Egypt (Rasmusson 1985; Czembor and Czembor 2000). Powdery mildew, caused by the pathogen Erysiphe graminis DC. f. sp. hordei Em Marchal (synamorph Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei), is one of the most destructive foliar diseases of barley in areas with a maritime climate such as northern Europe, Japan and the Mediterranean coast. In recent years, this disease has also become more significant in areas with a dry and hot climate because of the increased use of irrigation and nitrogen fertilizer. Losses in barley yields due to powdery mildew can reach 20% in Europe and 30% in North Africa (Scott and Griffiths 1980; Rasmusson 1985; Zine Elabidine et al. 1992; Czembor and Czembor 1998, 1999b). Plant Genetic Resources Newsletter, 2000, No. 123 53 Egypt is located in an area where different phytogeographical regions meet. The deserts of Egypt have widely different ecosystems. Marsa Matrruh province in western Egypt is characterized by deep depressions reaching more than 100 m below sea level, such as the Qattara depression and the oases. On the other hand, high mountains rising more than 2100 m asl occur in Sinai and in the As Sahra Ash Sharqiyah (eastern desert). Rain-fed agriculture prevails in the northwest coastal strip from Alexandria to the Libyan border and in north Sinai, with average annual precipitation of 100-250 mm. In these regions barley is still grown as landraces, both for grain and straw, in marginal low-input drought-stressed environments. The importance of barley landraces in these areas is due to the fact that they are often the only possible rain-fed crop (AboElenein et al. 1995; Batanouny 1995; Madkour and Abou-Zeid 1995; FAO 1996). In Europe during the 19th century, a few farmers and landowners such as Knight in England, Janasz in Poland, Vilmorin in France and Rimpau in Germany started to select desirable plants from landraces, based upon their phenotypic variation (Janasz 1893; Jensen 1988; Zeven 1996, 1998). Often only one line was selected as a new cultivar and the landrace from which this line was selected was no longer maintained. This has resulted in a great deal of genetic erosion of major crops during the last 100 years. In most European countries today landraces of major crops, including barley, exist only in genebanks (Brush 1992; Zine Elabidine et al. 1995; Hammer et al. 1996; Podyma 1997). Genetic studies of barley resistance to powdery mildew started in 1907 when Biffen showed that the resistance of Hordeum spontaneum is controlled by a single recessive gene. Currently powdery mildew on barley is considered as one of the most clearly characterized system of host-pathogen genetic interaction and more than 100 barley powdery mildew resistance alleles have been identified. Most of these genes originated from barley landraces from West Asia, Ethiopia and North Africa (Biffen 1907; Czembor 1976; Jensen and Jørgensen 1991; Jørgensen 1992b, 1994). Powdery mildew on barley can be controlled by the use of fungicides and/or resistant cultivars. About 20 years ago fungicide treatment against E. graminis f. sp. hordei became a common practice in order to reduce the severity of powdery mildew. However, pathotypes of E. graminis f. sp. hordei resistant to commonly used fungicides have now been identified. This, together with the cost of fungicides and environmental concerns regarding pesticide use in most developed countries, may lead to a gradual limitation of their use for control of powdery mildew (Gacek 1992; Brown and Kane 1994; Brown 1996). Breeding for resistance is a cheap and environmentally safe alternative approach to reduce the loss in yields caused by powdery mildew. However, breeding for resistance depends upon having genepools from which new genes can be introduced into existing cultivars. Such genepools are barley landraces, especially those originating from centres of origin for cultivated barley (Ceccarelli et al. 1987, 1995; Valkoun et al. 1995; ICARDA 1998; IPGRI 1999). The original area of cultivation of Hordeum vulgare L. was the Fertile Crescent (a crescent-shaped region of rich farmland that stretched in ancient times from the Mediterranean sea to the Persian Gulf, through the Tigris and Euphrates valley) and Egypt (Zohary and Hopf 1988; Nesbitt 1995; Willcox 1995). According to archaeological evidence barley was cultivated in this region in the ninth millennium B.C. (Wendorf et al. 1979, 1984; Williams 1988, 1995; Harlan 1995; Damania and Valkoun 1997). Vavilov (1926) believed the Mediterranean area to be one of the major centres of the crop’s origin. Recently, this hypothesis has been supported by the discovery of wild barley in North Africa (Molina-Cano and Conde 1980; Molina-Cano et al. 1982, 1984, 1999; Moralejo et al. 1994). This would suggest that in this region barley coevolved with the fungus E. graminis f. sp. hordei, therefore, barley landraces from Egypt may possess new genes for resistance to powdery mildew. The objective of this study was to determine whether genes resistant to powdery mildew are present in Egyptian landraces of barley. Materials and methods Plant material Drs J. Valkoun and S. Ceccarelli of ICARDA kindly provided seed samples of 135 Hordeum vulgare L. landraces. The seeds of 124 landraces were collected in three regions from 15-25 April 1987 (ICARDA collection code EGY87) and seeds of a further 11 landraces were collected from 18-20 April 1989 (ICARDA collection code EGY89). Of these, 79 landraces (58.5%) originated from Marsa Matrruh (Mediterranean coast, Libyan plateau, Qattara Depression and the Siwa Oasis), 47 (35%) originated from north Sinai and nine (6.5%) from As Sahra Ash Sharqiyah (eastern desert). All collected barley landraces were of a springgrowth type, had covered kernels and six-row heads. In Polish conditions they were intermediate in heading date and showed low resistance to lodging. Pathogens Thirty-five isolates of E. graminis f. sp. hordei Em Marschal were used (Table 1). These originated from collections in the Risø National Laboratory, Denmark; the Danish Institute for Plant and Soil Science, Denmark; the Edigenossische Technische Hochschule (ETH), Switzerland, kindly provided by Dr H.J. Schaerer; and from the Plant Breeding and Acclimatization Institute (IHAR) Radzików, Poland. The isolates were chosen according to differences in virulence spectra observed on the Pallas isolines differential set (Kølster et al. 1986) provided by Dr L. Munk (Royal Agricultural and Veterinary University, Denmark). They were purified by single pustule isolation, and maintained and propagated on young seedlings of the powdery mildew susceptible cultivar ‘Manchuria’ (CI 2330). Frequent virulence checks were made to assure the purity of isolates throughout the experiment. Disease assessment After 8-10 days incubation, the infection types were scored according to a 0-4 scale developed by Mains and Dietz (1930). The seedlings were classified into susceptible or resistant groups. Plants scoring 0-2 were included in the resistant group and plants scoring 3-4 were included in the susceptible group. Resistance tests This investigation was conducted during 1996-99 at IHAR P22 P23 P24 P12 P13 P14 P15 P17 P18 P19 P20 P21 P10 P11 P8B P9 P8A P7 P4B P6 P4A 0(4) 2 4 4 2 4 3 4 4 2 2 4 0 4 4 4 4 4 4 4 4 4 0 1 0 0(4) 4 4 4 4 4 4 4 4 0 0 4 0 2 4 4 4 4 4 4 4 4 4 0 0 0(4) 4 4 4 1 4 4 4 4 2 2 4 0 0 0 4 0 0 4 4 4 4 0 0 0 0(4) 4 4 0 1 4 4 4 4 2 2 4 4 4 4 4 4 4 4 4 4 4 4 0 0 0(4) 3 0 4 1 0 4 0 4 2 4 0 0 0 0 0 0 0 1 0 0 4 4 0 0 A6 0(4) 2 4 4 1 4 2 2 4 2 2 0 0 0 0 0 0 0 1 0 2 4 4 0 0 D17 0(4) 3 4 4 1 4 4 2 4 2 2 0 4 0 0 4 0 0 0 0 0 4 4 0 0 EmA30 0(4) 2 4 4 1 4 2 2 4 2 2 4 0 0 0 0 0 0 0 1 0 4 0 0 4 GE 3 2 0 4 2 4 2 2 4 1 2 4 0 0 0 0 0 0 2 2 2 4 0 0 4 HL3/5 3 3 4 4 1 4 4 0 4 2 2 4 0 0 0 0 0 0 2 0 0 4 0 0 4 0(4) 3 4 0 2 4 2 4 4 2 4 0 0 0 4 4 4 4 4 4 4 4 0 0 0 HL3/5-1 JEH11 11 0(4) 2 4 4 2 0 2 0 3 2 2 4 2 4 0 0 0 0 4 4 2 4 0 0 4 MH1 12 0(4) 4 4 4 1 0 0 2 4 2 2 4 4 4 0 0 0 0 4 4 2 4 0 0 0 MH1-2 13 0(4) 3 4 4 2 4 4 2 4 2 2 0 4 0 0 1 0 0 2 2 2 4 0 0 4 R13C 14 0(4) 4 4 4 1 4 4 2 4 2 2 0 4 4 0 2 0 0 4 4 4 4 0 0 4 R63 15 0(4) 4 4 0 2 4 4 2 4 2 2 0 4 0 0 4 0 0 2 1 1 4 0 0 0 R71/1 16 0(4) 4 4 4 2 4 2 2 4 2 2 0 0 0 0 0 0 0 2 2 2 4 0 0 4 R86.1 17 Mla8 Mla1 Mla3 Mla6, Mla14 Mla7, Mlk,? Mla7,? Mla7, Ml(LG2) Mla9, Mlk Mla9, Mlk Mla9 Mla10, Ml(Du2) Mla12 Mla13, Ml(Ru3) Mla22 Mla23 Mlra Ml(Ru2) Mlk Mlnn Mlp Mlat Mlg, Ml(CP) mlo5 Ml(La) Mlh 63-1 10 Pallas P1 P2 P3 59-12 9 59-11 8 58-74 7 1 Gene Isolines 6 2 Isolates Differential set 5 Table 1. Differential isolates and their infection types on Pallas differential sets 4 Plant Genetic Resources Newsletter, 2000, No. 123 3 54 P22 P23 P24 P12 P13 P14 P15 P17 P18 P19 P20 P21 P10 P11 P8B P9 P8A P7 P4B P6 P4A Pallas P1 P2 P3 Mla8 Mla1 Mla3 Mla6, Mla14 Mla7, Mlk,? Mla7,? Mla7, Ml(LG2) Mla9, Mlk Mla9, Mlk Mla9 Mla10, Ml(Du2) Mla12 Mla13, Ml(Ru3) Mla22 Mla23 Mlra Ml(Ru2) Mlk Mlnn Mlp Mlat Mlg, Ml(CP) mlo5 Ml(La) Mlh 18 Isolines Gene 20 0(4) 2 4 4 1 4 2 2 4 2 2 0 0 0 4 0 1 1 2 0 2 4 0 4 4 0(4) 2 4 0 2 4 4 4 3 2 4 4 0 0 4 4 4 4 4 4 4 4 0 0 0 0(4) 3 4 0 2 4 2 4 4 2 2 4 0 4 4 4 4 4 0 0 0 4 0 0 0 R189 R261 R275 19 Isolates Differential set 0(4) 3 3 0 1 3 2 0 0 0 0 3 0 0 0 4 0 0 0 0 0 4 0 0 0 R303 21 0(4) 4 4 4 1 4 2 1 4 2 2 4 0 0 0 0 0 0 0 0 0 4 0 0 4 Ru3 22 0(4) 4 4 4 2 4 2 4 4 2 2 4 4 0 4 4 4 4 2 1 2 4 4 4 0 TR2 23 0(4) 4 0 0 2 4 2 2 4 2 2 4 4 0 0 4 0 0 2 0 2 4 0 0 0 Ry4d 24 0(4) 4 4 4 1 4 4 4 4 2 2 4 4 4 0 4 0 0 4 4 4 4 0 0 0 En1/A1 25 0(4) 4 4 0 1 4 4 2 4 2 2 4 0 0 0 0 0 0 0 0 0 4 0 0 0 R303.1 26 0(4) 4 0 0 2 4 4 4 4 2 2 4 4 0 0 4 0 0 4 4 4 4 4 0 4 E92 27 0(4) 2 4 4 2 4 4 4 4 2 2 4 0 0 0 4 0 0 4 4 4 4 0 0 0 59-11.1 28 0(4) 4 4 4 2 4 4 0 0 2 4 4 4 0 0 0 0 0 2 0 2 4 0 4 4 SZ/C10 29 0(4) 4 4 4 2 4 4 2 4 2 2 0 0 0 0 0 0 0 0 0 0 4 0 0 4 Ra7 30 0(4) 4 4 0 2 4 4 4 4 2 2 4 4 0 0 4 0 0 4 2 4 4 0 4 4 Ra9 31 33 34 0(4) 4 4 4 2 4 4 4 4 2 4 4 4 4 0 4 0 0 4 1 4 4 4 0 4 0(4) 4 4 4 1 4 4 4 4 4 4 4 4 4 0 4 0 0 4 2 4 4 4 0 4 0(4) 4 4 0 1 4 4 4 4 2 2 4 2 0 4 4 4 4 4 4 4 4 0 0 4 Ra10 Ra13 Ra16 32 0(4) 4 4 0 2 4 4 4 2 0 2 4 4 4 0 4 0 0 4 4 4 4 0 0 4 Ra22 35 Plant Genetic Resources Newsletter, 2000, No. 123 55 56 Plant Genetic Resources Newsletter, 2000, No. 123 Radzików, Poland. In the winter of 1996-97 approximately 30 plants per landrace were evaluated in a greenhouse with the R303 isolate of E. graminis f. sp. hordei. R303 represented the most avirulent isolate available, allowing the expression of a maximum number of resistance genes. The cultivar ‘Manchuria’ was used as a susceptible control. In addition, approximately 30 plants per landrace were evaluated in a greenhouse with a mixture of E. graminis f. sp. hordei isolates with all the virulences known in Europe. Again the cultivar ‘Manchuria’ was used as a susceptible control. Eight (6%) of the 135 landraces showed resistance reactions (Table 2). From one to five resistant plants for each landrace were grown in the greenhouse to obtain seed. In this manner, 11 single plant lines were created. Three of these lines were tested with 17 isolates of powdery mildew during the winter of 1997-98 (Table 3). Another eight lines were tested with 23 isolates during the winter of 1998-99 (Table 4). This research was conducted in the IHAR Radzików greenhouse. The plants were grown with 16 h light and a temperature range of 16-22oC. Inoculation was carried out when the plants were 10–12 days old by shaking or brushing conidia from diseased plants. The disease reaction types shown by seedlings were scored after 8-10 days incubation. Eleven single plant lines were selected. All these lines possessed one or more resistance alleles to powdery mildew of barley (Tables 3, 4). However, only one line (441-1-1) expressed resistance to all isolates used. It was impossible to determine which specific gene or genes for resistance are present in line 441-1-1 (Table 4). Based on the assumption that different resistance genes may condition different infection types it may be concluded that this line had more than one resistance gene (Table 5). The distribution of infection types indicates that 80% of all reaction types observed were classified as powdery mildew resistance (score 0, 1 and 2). The most frequent score was 2 (75%). Ten lines had a score of 2 for most of the isolates used and one line (476-2-2) scored 4 (susceptible) for more than 50% of the isolates used. In nine lines (82%), the presence of previously unknown genes in combination with a specific one was detected (Table 3, 4). Two different resistance alleles Mlat and Mla7 were postulated to be present in the tested lines. The most common resistance allele in the tested lines was Mlat. This allele was postulated to be present in nine (82%) of the tested lines. Allele Mla7 was postulated to be present in line 476-2-2 together with an unknown gene or genes. Postulation of resistance alleles Hypotheses about the specific resistance genes present were made by comparing the reaction spectra of the tested lines with those of differential lines. Identification of resistance genes was made by eliminating resistance genes not present in tested lines. The next step was to determine the postulated and possible resistance genes (Brown and Jørgensen 1991; Czembor and Czembor 1998, 1999b). This was done on the basis of the gene for gene hypothesis (Flor 1956). Discussion Results Among the 135 landraces from Egypt, eight (6%) expressed resistance to isolate R303 of E. graminis f. sp. hordei (Table 2). From the three regions in Egypt from which the landraces originated only landraces collected in Marsa Matrruh and north Sinai expressed resistance to powdery mildew. All landraces collected in As Sahra Ash Sharqiyah were susceptible to R303 isolate. Many studies show that barley landraces are rich sources of resistances to pests and pathogens. These landraces evolved during the period of primitive agriculture by more or less deliberate selection by farmers to obtain plants with desirable characteristics. This selection favoured the plants best fitted to survive and those which gave the highest yields of a good quality product. As very susceptible plants gave no seed, this selection resulted in plants which were not very susceptible to damaging pests or diseases (Jørgensen 1994; Valkoun et al. 1995; Madeley 1996; Jørgensen and Jensen 1997; IPGRI 1999; Czembor and Czembor 2000). This study shows that barley landraces from Egypt are a valuable source of resistance to powdery mildew. Of the 135 barley landraces from Egypt tested, eight (6%) showed resistance to E. graminis f. sp. hordei. The region of Marsa Matrruh is worth noting out of the three regions of Egypt from which the Table 2. Site of collection of eight barley landraces from Egypt showing resistance to powdery mildew Landraces ICARDA coll. code Altitude (m asl) Province Site El Gura; 214 km S Sheik Zwaied Al Matareh; 12 km west Marsa Matrruh Em Rakham Bahri; 30 km west Matrruh Abu Lahu Bahri; 36 km NW Marsa Matrruh Samala; 10 km east Marsa Matrruh Ras Al Hekma; 68 km east MatrruhAlexandria Zaqawa village in Siwa oasis El Hitabit in Siwa oasis No. IHAR no. ICARDA no. 1 2 415 440 ICB 32493 ICB 32518 EGY87 EGY87 95 5 North Sinai Marsa Matrruh 3 441 ICB 32519 EGY87 - Marsa Matrruh 4 443 ICB 32521 EGY87 5 Marsa Matrruh 5 6 471 476 ICB 32549 ICB 32554 EGY87 EGY87 15 85 Marsa Matrruh Marsa Matrruh 7 8 607 610 ICB 32998 ICB 33001 EGY89 EGY89 -5 -5 Marsa Matrruh Marsa Matrruh 2 4 2 2 2 2 2 2 2 2 2 D17 6 2 1 1 GE 8 11 12 2 1 2 4 4 4 2 2 1 HL3/5 JEH11 MH1 9 Unidentified resistance allele not present in the Pallas isolines set. 2 2 2 58–74 59-11 63-1 1 Isolates 2 2 2 R13C 14 2 2 2 R63 15 2 2 2 R71/1 16 2 2 2 R86.1 17 2 2 2 R189 18 3 4 5 2 2 2 2 4 4 2 2 2 2 2 0 2 4 2 2 4 4 4 0 4 2 2 4 10 11 13 18 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 4 4 4 2 4 4 4 4 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 EmA30 HL3/ JEH11 MH1-2 R189 5-1 7 Unidentified resistance allele not present in the Pallas isolines set. 2 2 2 2 2 4 2 2 58 59 63 A6 -74 -12 -1 1 Isolates 22 23 2 2 2 1 2 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2 2 4 2 2 R303 Ru3 TR2 21 2 2 2 2 0 4 2 2 En1/ A1 25 2 2 2 2 2 2 2 2 R303.1 26 2 2 2 0 2 4 0 2 E92 27 415-1-1 440-1-1 440-1-2 441-1-1 443-1-5 471-1-3 471-4-5 476-1-1 476-2-2 607-1-2 610-1-1 Landrace IHAR no. 0 0 0 4 0 1 0 0 0 0 0 0 0 0 0 4 0 0 2 2 0 0 0 1 18 19 18 15 15 13 13 13 10 17 20 2 0 0 0 0 0 0 0 0 0 0 0 3 No. of isolates that produced infection type 4 4 5 0 2 6 2 2 13 4 3 4 22 23 23 23 17 23 17 17 23 23 23 Total Table 5. Infection types – frequency in 11 Egyptian landraces for isolates of E. graminis f. sp. hordei † 415-1-1 440-1-1 440-1-2 441-1-1 471-1-3 476-2-2 607-1-2 610-1-1 Lines 2 2 2 2 2 4 2 2 59 -11.1 28 2 2 4 2 4 2 4 4 SZ/ C10 29 Table 4. Resistance alleles and infection types of eight lines to infection by 23 isolates of E. graminis f. sp. hordei † 443-1-5 471-4-5 476-1-1 Lines Table 3. Resistance alleles and infection types of three lines to infection by 17 isolates of E. graminis f. sp. hordei 2 2 2 2 2 2 2 2 Ra7 30 4 4 4 2 2 2 0 2 4 2 2 Ra9 31 R261 19 2 2 2 4 4 4 2 4 4 4 2 Ra10 32 R275 20 4 4 4 2 4 4 4 2 Ra13 33 2 2 2 R303 21 2 2 2 1 2 4 2 2 Ra16 34 2 2 2 Ry4d 24 2 2 2 2 2 4 0 2 Ra22 35 Mlat, +?† Mlat, +?† Mlat, +?† +?† Mlat, +?† Mla7, +?† Mlat, +?† Mlat, +?† Postulated resistance alleles Mlat Mlat, +?† Mlat, +?† Postulated resistance alleles Plant Genetic Resources Newsletter, 2000, No. 123 57 58 Plant Genetic Resources Newsletter, 2000, No. 123 landraces originated, as the highest percentage (10%) of landraces collected in this region expressed resistance to barley powdery mildew. In addition, line 441-1-1, which possesses resistance to all powdery mildew isolates used in this study, originates from landraces collected in this area. Based on the results of this study, the barley landraces which will be collected in future germplasm collecting missions in the Marsa Matrruh region should have high levels of powdery mildew resistance. Organizing collecting expeditions in Egypt is highly recommended because barley landraces in North Africa are subject to genetic erosion due to drought and desertification (Perrino et al. 1986; Damania 1988). Isolates used in this experiment had virulency to all the major resistance genes currently found in Europe. Therefore, it can be concluded that line 441-1-1 is resistant to all the major virulence genes present in populations of powdery mildew in Europe. The distribution of infection types indicates the minimum number of genes involved because different genes for resistance may elicit a different reaction type. Based on this assumption, it may be concluded that line 441-1-1 may have many genes for resistance. This line should be used in barley breeding programmes as a new and very valuable source of resistance to powdery mildew. The frequency of powdery mildew resistant landraces to all isolates of powdery mildew in the present study was less than 1%, which is smaller or similar to the findings of other studies (Honecker 1938; Nover and Lehmann 1973; Czembor 1976, 1999; Czembor et al. 1979; Negassa 1985; Lehmann and von Bothmer 1988; Leur et al. 1989; Jørgensen and Jensen 1997; Czembor and Johnston 1999; Czembor and Czembor 1999a, 2000). Divergences may relate to differences in methods and isolates of powdery mildew used to screen landraces for resistance in the different studies. The presence of unknown genes alone or in combination with specific ones was postulated to be present in 10 lines. Two different resistance alleles Mlat and Mla7 were postulated to be present in the lines. The most common resistance allele in the tested lines was Mla, found in nine (82%) of the tested lines. Allele Mla7 was present in line 476-2-2 together with an unknown gene or genes. These findings are in line with the fact that virulence to these genes is common in the North African mildew population (Yahyaoui et al. 1997). The presence in barley landraces of a high number of genes different from the major resistant genes used in Europe agrees with findings in other studies (Honecker 1938; Nover and Lehmann 1973; Czembor 1976, 1999; Czembor et al. 1979; Negassa 1985; Lehmann and von Bothmer 1988; Leur et al. 1989; Jørgensen and Jensen 1997; Czembor and Johnston 1999; Czembor and Czembor 1999a, 2000). New genes for resistance to barley powdery mildew are needed. In the 20th century approximately 40 alleles for racespecific resistance to powdery mildew, either alone or in combination, have been used in Europe since the first gene, Mlg, was introduced on a large scale in the 1930s in Germany. The most common resistance genes used by barley breeders were Mla6, Mla7, Mla9, Mla12 and Mla13 belonging to the Mla locus and the resistance alleles Mlk, Mlg, MlLa, Mlh and Mlra (Brown and Jørgensen 1991; Jørgensen 1992b, 1994; Czembor and Czembor 1998, 1999b). These genes have been used in approximately 700 cultivars. However, virtually all these genes are gradually overcome by virulent races within four to five years when cultivars containing them are grown on a large acreage (Czembor and Gacek 1987, 1995; Jørgensen 1992b, 1994; Wolfe and McDermott 1994). This occurs because E. graminis f. sp. hordei is able to develop new races which rapidly spread across Europe on susceptible barley cultivars. A high level of pathogenic variability in local populations has been demonstrated in many studies (Limpert 1987; Hovmøller and Østergård 1991; Huang et al. 1995; Müller et al. 1996). What is more, 28 alleles for resistance to powdery mildew are closely linked or allelic. This limits the possible number of gene combinations in breeding new barley cultivars (Czembor and Gacek 1990, 1996; Brown and Jørgensen 1991; Czembor and Czembor 1998, 1999b). The use of genes originating from landraces for resistance to powdery mildew should be a relatively easy task as there should be no problems of sterility or other abnormalities that would occur when mutants or some wild barley are used (Burdon and Jarosz 1989; Jørgensen 1994). A good example of this is the introduction of Mlo resistance into modern European barley cultivars. All 25 different mlo alleles, with the exception of mlo11, were obtained by mutagenesis. However, almost all barley cultivars with mlo resistance have the same allele mlo11, which originated from the Ethiopian landrace L92 (Jørgensen 1992a, b, 1994; Schwarzbach 1997) Tests performed on seedlings for powdery mildew resistance are usually sufficient for the needs of breeders and pathologists. However, these tests do not necessarily predict the resistance of the adult plant (Brown and Jørgensen 1991; Jensen and Jørgensen 1991; Jensen et al. 1992; Czembor and Czembor 1998, 1999b). The new sources of resistance to powdery mildew in barley landraces from Egypt, identified in this study, confer resistance against all, or at least to a large number, of the powdery mildew virulence genes present in Europe. Therefore, they can make a significant contribution to the diversity of the powdery mildew resistance genepool available to barley breeders. Acknowledgements The author thanks Drs J. Valkoun and S. Ceccarelli, ICARDA for kindly providing seed samples of barley landraces from Egypt, Dr H.J. Schaerer, ETH, Switzerland for the powdery mildew isolates and Dr L. Munk, Royal Agricultural and Veterinary University, Denmark for the Pallas near-isogenic lines. References AboElenein, R.A., E.T. Kishk and A.M. Abd El Shafi Ali. 1995. Germplasm needs critical for arid lands of Egypt. 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ARTICLE Plant Plant Genetic Genetic Resources Resources Newsletter, Newsletter, 2000, 2000, No. No. 123:123 61 - 61 67 Genotypic variation of Kenyan tomato (Lycopersicon esculentum L.) germplasm S.G. Agong¹*, S. Schittenhelm² and W. Friedt³ ¹ Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000, Nairobi, Kenya. Email: [email protected] ² Institute of Crop Science, Federal Agricultural Research Centre, Braunschweig-Völkenrode (FAL), Bundesalle 50, D-38116 Braunschweig, Germany ³ Institute of Crop Science and Plant Breeding I, Justus-Liebig University Giessen, Ludwig Str. 23, D-3539 Giessen, Germany Summary Genotypic variation of Kenyan tomato (Lycopersicon esculentum L.) germplasm Systematic genotypic analysis of Kenyan tomato germplasm was carried out in order to delineate potential variability based on various morphological, agronomic and biochemical traits. Both landraces and market cultivars were examined with a view to facilitating tomato improvement. In an experiment conducted in 1993 in a glasshouse at the Federal Agriculture Research Centre (FAL), Germany, 26 tomato landraces and nine market cultivars were investigated using a four-replicate completely randomized block design. Analysis of variance clearly illustrated a large variation for all the quantitative traits. Landraces on average produced more fruit per plant (90) but of a smaller size than the market cultivars (19). However, market cultivars had a superior average fresh fruit weight of 56.5 g while the landraces registered on average 40.6 g. Multiple correlation analysis confirmed the superiority of landraces for traits of fruit quality and a strong negative association between fruit biochemical parameters and fresh fruit weight. Limited structural groupings were detected on the basis of a principal components analysis. Using this method, processing and fresh tomato cultivars within the germplasm could be clearly separated on the basis of fruit characters. Furthermore, this analysis distinguished a few landraces from the market cultivars, although closer phylogeny through introgression was highly suspected. Within the landraces, the yellow-cherry types were distinct from all the others. On the basis of this study, the use of more prolific landraces, in terms of number of fruit as well as actual fruit yield, would be desirable for intensive and continuous production of tomatoes. Key words: Genetic diversity, landraces, Lycopersicon esculentum, phylogenetic relationships, principal components analysis, tomato Résumé Resumen Une analyse génotypique systématique du matériel génétique de tomate du Kenya a été effectuée en vue de définir la variabilité potentielle sur la base de divers caractères morphologiques, agronomiques et biochimiques. On a examiné tant les races locales que les cultivars commerciaux dans le but de faciliter l’amélioration de la tomate. Dans une expérience réalisée en serre en 1993 au Centre fédéral de recherche agricole (FAL) en Allemagne, 26 races locales de tomates et neuf cultivars commerciaux ont été étudiés à l’aide d’un dispositif de blocs complètement randomisés avec quatre répétitions. L’analyse de la variance a montré clairement une importante variation pour tous les caractères quantitatifs. Les races locales ont donné en moyenne plus de fruits par plante (90) mais ils étaient plus petits que ceux des cultivars commerciaux (19). Toutefois, les fruits frais provenant de cultivars commerciaux ont affiché un poids moyen supérieur (56,5 g), à celui des fruits des variétés locales (40,6 g en moyenne). Une analyse de corrélation multiple a confirmé la supériorité des races locales pour les caractères de qualité des fruits et une association négative importante entre les paramètres biochimiques des fruits et le poids des fruits frais. Des groupements structurels limités ont été détectés sur la base d’une analyse en composantes principales. Par cette méthode, les cultivars de tomates pour la transformation ou la consommation en frais pourraient être nettement séparés sur la base des caractères des fruits. Cette analyse a aussi permis de différencier quelques races locales des cultivars commerciaux, mais l’on soupçonne qu’il existe une phylogénie plus étroite par introgression. Parmi les races locales, les types jaune-cerise se distinguent de tous les autres. Sur la base de cette étude, on peut conclure que l’utilisation de races locales plus prolifiques, en termes de nombre de fruits et de rendement effectif en fruits, serait souhaitable pour une production continue et intensive de tomates. Se procedió a un análisis genotípico sistemático del germoplasma del tomate keniano para trazar la variabilidad potencial en función de diversos rasgos morfológicos, agronómicos y bioquímicos. Se examinaron variedades locales y cultivares comerciales con miras a facilitar la mejora del tomate. En un experimento realizado en 1993 en un invernadero del Centro Federal de Investigación Agrícola (FAL) de Alemania, se investigaron 26 variedades locales de tomates y nueve cultivares comerciales utilizando un diseño en bloque cuadruplicado completamente aleatorio. El análisis de varianza ilustró claramente una amplia variación para todos los rasgos cuantitativos. Las variedades locales produjeron en promedio más frutos por planta (90), pero de menor tamaño que los cultivares comerciales (19). No obstante, los cultivares comerciales alcanzaban un promedio más alto de peso del fruto fresco: 56,5 g frente al promedio de 40,6 g de las variedades locales. El análisis de correlación múltiple confirmó la superioridad de las variedades locales en la calidad del fruto y una fuerte asociación negativa entre los parámetros bioquímicos del fruto y el peso del fruto fresco. Se detectaron agrupaciones estructurales limitadas sobre la base de un análisis de componentes principales. Con este método pudieron separarse claramente, dentro del germoplasma, los cultivares de tomate frescos y procesados, en función de las características del fruto. Por otra parte, este análisis distinguió unas pocas variedades locales de los cultivares comerciales, aunque había fuertes sospechas de filogenia más próxima por introgresión. Dentro de las variedades locales, los tipos amarillocereza eran distintos de todos los demás. Según este estudio, el uso de variedades locales más prolíficas tanto en número de frutos como en rendimiento efectivo del fruto sería deseable para la producción intensiva y continua de tomates. Variation génotypique du matériel génétique de tomate du Kenya (Lycopersicon esculentum L.) Variación genotípica del germoplasma del tomate keniano (Lycopersicon esculentum L.) Introduction With the increasing need of consumers for both quality and diversity of tomato products, there is a need to extensively collect, exploit and evaluate unknown tomato germplasm. To- mato continues to play a key horticultural role in Kenya and its improvement would enhance agricultural productivity, alleviate poverty and facilitate food security (Agong and Schittenhelm 62 Plant Genetic Resources Newsletter, 2000, No. 123 1993; Agong et al. 1997). However, most of the tomato germplasm in the country is largely undocumented and has unknown morphological, agronomic and biochemical attributes. Tomato is continuously introduced and grown in all ecological zones where arable agriculture is practicable. This tendency has fuelled the extensive cultivation of various tomato cultivars with unclear documentation (Agong and Schittenhelm 1993). Systematic study and characterization of tomato germplasm is of great importance for current and future agronomic and genetic improvement of the crop. Furthermore, if an improvement programme is to be carried out evaluation is imperative, in order to understand the genetic background and the breeding value of the available tomatoes. Morphological, agronomic as well as biochemical parameters have been widely used in the evaluation of various crops (Rick and Holle 1990; Weber and Wricke 1994; Kaemmer et al. 1995). Exploitation of such traits increases our knowledge of the genetic variability available and strongly facilitates breeding for wider geographic adaptability, with respect to biotic and abiotic stresses. In addition, genetic diversity needs to be described and measured if it is to be effectively incorporated into breeding strategies and management of plant genetic resources. The objective of this study, therefore, was to examine the variation in tomato germplasm based on the morphological, agronomic and biochemical traits in the landraces, as well as in market cultivars, with an ultimate view of identifying potential accessions to improve tomato production. This study also aimed to generate data to increase understanding of the phylogeny of the Kenyan tomato germplasm to improve effective management. Materials and methods Tomato (Lycopersicon esculentum L.) accessions collected from different parts of Kenya, as described by Agong and Schittenhelm (1993) and Agong et al. (1997), were used in this study. Germplasm was comprised mostly of landraces grown by mainly small-scale farmers over several years, and collected mainly in the western, central, eastern and coastal regions of Kenya. These areas differ greatly in their agro-ecological and ethnic compositions. Morphological, agronomic and biochemical characterization of the tomato germplasm was conducted with the hypothesis that any differences among the tomato accessions would be due to the genetic differentiation therein and not solely to phenotypic plasticity, given the diverse environmental differences between the collection sites (Agong and Schittenhelm 1993). Using a four-replicate randomized complete block design, a pot experimental study under a controlled glasshouse environment was conducted from February to August 1993 at FAL. For each replicate, 12 plants per accession were studied. In the experiment 35 accessions were used, including three of German origin used as a control. The tomatoes were grown in an organically enriched Völkenrode compost soil following standard horticultural practice, as described in Agong et al. (1997). Throughout the experiment, glasshouse temperatures were kept at 15°C at night and 25°C during the day and relative humidity maintained at 70%. The seedlings were pricked out into 26 cm plastic pots four weeks after emergence and cultured up to bright-red fruit maturity. The parameters scored during vegetative growth and through fruit maturity included: total fruit set (% FS), total number of fruit per plant (NF), fresh fruit weight per plant of mature fruits (g FFW), plant height at fruit maturity (cm PH), mature fruit dry matter content (% DC), dry fruit weight of mature fruit (g DFW), mature fruit index (FI), thousand-seed weight (g SW), electrical conductivity (dS/m EC), pH value (pH), Brix (% BRI), titratable acidity (% TA), citric acid (mM/L CA), malic acid (mM/L MA], fructose (% FRU) and glucose (% GL) of mature fruit. Fruit juice extracts from each tomato accession were obtained and stored at -20°C for the chemical analysis. From each of the 12 plants per accession in every replication, 5 g of juice extract was obtained to provide a 60 g mixed juice sample for use in the biochemical analyses. Sampling was done carefully to ensure that fruit from all the accessions was at an approximately similar physiological maturity (bright red ripe). Thawed juice samples were vigorously shaken and used to determine the electrical conductivity and pH values according to the procedures of Agong et al. (1997). The percentage of total soluble solids was measured by the use of a sucrose hand refractometer (model HRN-20 of Krüss-W.S.R. Tokyo). Sugars (glucose and fructose) and organic acids (citric and malic) were analyzed from the homogenously mixed fruit-juice extract using high performance liquid chromatography (HPLC) as described by Mitchell et al. (1991). However, the sugars were extracted in distilled water and not in 60% ethanol. The separation of sugars and organic acids was accomplished on an AminexTM HPX-87H 300 x 7.8 mm column (BIO-RAD, Richmond, California) with a degassed 0.05 N H2SO4 as the mobile phase (eluant) at a flow rate of 0.4 ml/min. Sugars were detected with a differential refractometer (RI-Detektor, Knauer) and organic acids by UV absorbance at 210 nm. All samples were run at a constant temperature of 30°C. Titratable acidity was determined using the methods of the National Canners Association (1968) and Agong et al. (1997). By using the computer program SAS (SAS Institute Inc. 1990) an analysis of variance (ANOVA) was carried out to determine the significance of differences. Multiple correlation and principal components analysis (PCA) were carried out as described by Broschat (1979) on the standardized and normalized mean values of the metric characters and correlation matrices. Results The evaluation of the Kenyan tomato germplasm showed a large and significant variation in the quantitative traits between the accessions (Tables 1a, b). For example, the percentage of fruit set was scored at 39.6 and 94.9% for accessions 7 and 24, respectively. The average fresh and dry fruit weights varied notably among the accessions. Most of the landraces gave lower fresh and dry fruit yields than the market cultivars. On the other hand, the landraces displayed superiority with respect to biochemical parameters. For example, landraces 29, 31 and 33 had very high levels of Brix (Table 1b). Electrical conductivity for all Plant Genetic Resources Newsletter, 2000, No. 123 63 Table 1a. Accession means for yield-related characters in tomato Accession no. 2M 3M 4M 5M 6M 7M 8M 9M 10M 11L 12L 13L 14L 15L 16L 17L 18L 19L 20L 21L 22L 23L 24L 25L 26L 27L 28L 29L 30L 31L 32L 33L 35GL 36GL 37GL X‡ LSD(0.05)§ Character† FS (%) NF FFW (g) DFW (g) FI NS SW (g) DC (%) 89.4 70.3 76.4 90.3 79.0 39.6 74.1 71.3 79.3 69.9 61.8 58.6 78.4 65.8 78.9 82.0 85.5 64.1 72.3 81.7 72.0 79.5 94.9 58.8 80.4 48.9 79.2 89.1 74.6 83.9 79.0 84.9 98.5 46.0 95.7 75.3 10.7 22.0 13.5 24.7 24.6 27.3 10.1 19.4 14.5 17.3 26.5 24.3 27.0 23.0 34.9 27.5 26.8 47.1 33.0 21.2 28.9 72.9 44.0 83.7 30.1 26.3 11.2 25.1 158.9 28.0 115.2 21.0 73.4 103.1 9.7 14.0 37.4 4.6 35.9 92.6 49.4 37.0 39.1 83.3 48.4 65.8 57.0 35.2 31.5 33.0 41.7 30.2 42.7 37.8 16.9 28.8 51.2 35.1 7.9 15.7 14.7 43.5 45.0 82.1 39.0 2.6 33.7 4.3 55.8 8.2 5.4 90.7 80.4 40.6 7.2 3.4 7.2 4.2 2.6 2.9 7.6 4.0 7.5 4.1 2.6 2.7 2.3 3.1 2.3 4.9 2.9 1.4 2.5 3.8 3.0 0.8 1.6 1.3 3.2 3.4 3.4 5.2 0.3 2.4 0.4 4.4 0.8 0.5 8.4 6.4 3.4 0.7 0.96 1.47 1.24 0.86 0.81 1.44 0.92 1.30 1.47 0.87 0.95 0.80 1.17 1.02 1.33 1.26 1.50 1.29 1.34 1.19 1.37 1.33 0.81 1.30 1.25 1.39 1.18 1.04 1.00 1.06 1.07 1.23 1.03 1.49 1.51 1.18 0.08 66 160 131 64 58 170 51 151 72 74 69 77 119 87 141 93 107 117 112 80 80 113 42 111 95 200 109 73 67 96 121 91 49 196 119 102 13 2.53 2.80 3.06 3.27 2.81 2.68 3.42 2.99 3.77 3.23 3.00 3.12 3.21 2.52 2.89 2.86 2.64 2.90 3.01 2.89 1.93 2.41 2.02 1.92 2.89 2.60 3.09 1.11 2.93 1.24 3.32 1.79 2.00 2.65 2.79 2.69 0.17 9.6 7.7 8.5 7.2 7.4 9.1 8.3 11.4 7.1 7.5 8.6 6.9 7.4 7.7 11.5 7.7 8.4 8.6 7.3 8.6 10.5 9.8 8.6 7.4 7.6 4.2 13.4 11.0 7.2 10.4 7.9 10.2 9.8 9.2 8.0 8.6 0.8 † See ‘Methods’ for character definition. X = grand mean. § LSD(0.05) = least significant difference at 5% level. FS = fruit set; NF = number of fruit per plant; FFW = fresh fruit weight; DFW = dry fruit weight; FI = mature fruit index; NS = no. of seeds per fruit; SW = thousand-seed weight; DC = dry matter content; M = market cultivars; L = landraces of Kenyan origin; GL = landraces of German origin. ‡ accessions ranged between 6.5 and 9.4 dS/m. Similarly, the fruit juice extract of the landraces, particularly accessions 33 and 31, had the highest electrical conductivity. Correlation analysis revealed strong relationships among the biochemical traits (Table 2). As expected, the weight of fresh fruit was negatively associated to the fruit’s biochemical contents. Fresh fruit weight also correlated negatively to fruit number per plant and dry matter content. Positive correlationship, however, was observed between fresh fruit weight and fruit width and fruit equatorial length, whereas the number of fruit per plant was negatively correlated to fruit width. Visual appraisal of the germplasm during the vegetative and the reproductive phases also showed that the accessions were fairly variable. For example, observation of the reproduc- tive parts revealed that accession 33, a red-cherry tomato, had a pin flower form whereas the yellow-cherry and the market types displayed the thrum flower structure (Fig. 1). Similarly the fruit forms differed. The PCA on 15 unrelated but linearly correlated quantitative characters indicated that the first three principal components were adequate in explaining more than 70% of the phenotypic variation in the tomato germplasm (Fig. 2). However, no clear classes could be adduced from the analysis. To some extent it was possible to distinguish between accessions collected in the western, central and coastal areas of Kenya. An approximate classification is (a) landraces with yellow fruit from the coast, (b) landraces with red-cherry fruit from western Kenya, (c) a mixture of coastal, central and western accessions, (d) central 64 Plant Genetic Resources Newsletter, 2000, No. 123 Table 1b. Accession means for biochemical attributes of tomato fruit Accession 2M 3M 4M 5M 6M 7M 8M 9M 10M 11L 12L 13L 14L 15L 16L 17L 18L 19L 20L 21L 22L 23L 24L 25L 26L 27L 28L 29L 30L 31L 32L 33L 35GL 36GL 37GL X‡ LSD(0.05) § Character † EC pH BRIX (%) TA (%) GL (%) FRU (%) CA (mM/L) MA (mM/L) 7.8 7.0 7.3 7.5 6.6 7.5 7.3 6.5 7.1 6.9 7.3 6.8 6.7 6.7 6.7 6.8 8.2 6.6 7.0 7.4 8.0 8.0 7.6 8.5 7.0 7.1 7.3 7.4 7.0 9.4 6.7 9.3 8.6 7.5 7.4 7.3 0.6 4.1 4.1 4.2 4.1 4.3 4.2 4.4 4.2 4.1 4.3 4.5 4.3 4.3 4.4 4.3 4.3 4.2 4.3 4.2 4.1 4.1 4.2 4.2 4.2 4.1 4.2 4.2 4.1 4.4 4.0 4.2 3.9 3.8 4.2 4.2 4.2 0.7 8.5 7.9 7.4 7.3 7.0 8.8 8.4 6.8 7.6 6.8 8.4 7.3 7.3 7.2 7.0 7.4 7.4 7.4 7.1 7.6 8.4 8.3 8.0 7.3 7.0 8.4 8.1 10.5 7.4 9.0 7.2 9.5 8.1 8.7 7.1 7.8 0.8 0.9 0.7 0.6 0.7 0.5 0.7 0.5 0.6 0.8 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.8 0.6 0.6 0.7 0.7 0.6 0.6 0.4 0.6 0.6 0.6 0.8 0.5 0.8 0.5 1.0 1.2 0.6 0.5 0.6 0.1 2.3 2.6 2.3 1.8 2.0 2.2 2.0 1.6 2.0 2.1 2.4 2.5 2.1 2.0 2.1 2.2 2.1 2.1 2.0 2.0 1.9 1.4 2.4 2.3 2.1 2.3 2.4 2.9 1.8 2.3 1.8 2.5 1.4 2.2 1.3 2.1 0.7 2.5 2.6 2.5 2.0 2.2 2.5 2.1 1.7 2.0 2.2 2.5 2.7 2.2 2.1 2.2 2.5 2.3 2.3 2.2 2.2 2.3 1.4 2.6 2.5 2.3 2.5 2.5 3.6 1.9 2.7 1.9 2.9 1.6 2.5 1.6 2.3 0.7 46 43 33 44 34 36 32 39 39 24 24 30 27 28 29 21 41 34 31 34 43 42 36 25 30 31 31 66 24 61 30 67 62 36 28 36 6 73 45 56 49 34 42 80 40 56 73 73 17 85 63 13 61 38 62 49 60 47 41 43 23 43 73 50 37 97 43 20 39 45 18 11 48 55 † See ‘Methods’ for character definition. X= grand mean. § LSD(0.05) = least significant difference at 5% level. EC = electrical conductivity; TA = titratable acidity; L = glucose; FRU = fructose; CA = citric acid; MA = malic acid; M = market cultivars; L = landraces of Kenyan origin; GL = landraces of German origin. ‡ accessions with large fruit, (e) coastal accessions with large fruit and (f) a mixture of all accessions. Accessions 35, 36 and 37 were used for control purposes and do not affect the possible genotypic classifications. Market cultivars can be separated into three categories: 4 and 10; 3, 7 and 9; and 2, 5, 6 and 8. Tomatoes for processing (2, 5, 6 and 8) could clearly be separated on the basis of PCA analysis from the fresh market cultivars (3, 4, 7, 9 and 10). Discussion The heterogeneity observed in the germplasm is largely attributable to the genotypic variability within and between the individual tomato groups. The variation adduced in this study conforms with earlier work on the reaction of this germplasm to salinity stress (Agong et al. 1997). The availability of a base variable population, for example red and yellow cherry fruiting tomato types, is crucial for any significant progress in crop genetic advancement. Genetic improvement of tomato should not only depend on the introduction but also on the gradual development of more closely adapted accessions suited to local conditions (Agong 1995). On the basis of the morphological, agronomic and biochemical data generated in this study on yield and yieldrelated traits, it is suggested that fruit number per plant and fruit index (length/width), which are closely associated with fresh fruit yield (Table 2), can be used to create a better understanding of diversity in the tomato for yield and crop improvement (Cavicchi and Silvetti 1976). The percentage of fruit set and fruit number per plant were strongly correlated, hence this relationship can be useful for effective pruning management – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – 0.17 0.05 0.27 – – – – – – – – – – – – – 0.96** 0.34* –0.07 0.36* – – – – – – – – – – – – 0.64** 0.51** 0.69** –0.31 0.38* † EC = electrical conductivity, TA = titratable acidity. * Significant at P = 0.05; ** significant at 0.01. – – – – – – – – – – – 0.49** 0.14 –0.01 0.88** –0.87** 0.03 – – – – – – – – – – 0.62** 0.48** 0.19 0.08 0.63** –0.55** –0.07 – – – – – – – 0.70** 0.61** –0.49** –0.40* –0.41* –0.28 –0.14 –0.56** 0.17 –0.06 – – – – – – 0.72** 0.22 0.79** –0.61** –0.59** –0.55** –0.28 –0.09 –0.69** 0.43** –0.25 – – – – – –0.47** –0.32 –0.04 –0.36* 0.28 0.37* 0.38* 0.13 0.03 0.43** –0.28 0.28 – – – – –0.34* 0.74** 0.74** 0.32 0.73** –0.63** –0.55** –0.71** –0.29 –0.12 –0.68** 0.29 –0.05 – – – –0.78** 0.41* –0.86** –0.84** –0.41** –0.83* 0.54** 0.56** 0.64** 0.43* 0.22 0.76** –0.39* 0.15 – – 0.47** –0.15 0.27 –0.40* –0.50** –0.61** –0.18 0.24** 0.43 0.01 –0.16 –0.28 0.41 –0.36* 0.04 – 0.11 0.61** 0.49** 0.35** –0.79** –0.41** 0.14 0.73 0.48** 0.43** 0.44** 0.33 0.21 0.47** 0.41* 0.47** 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 no./ plant % cm g % cm cm – – – – – – – – 0.08 –0.20 –0.18 –0.03 0.01 0.09 –0.19 –0.04 0.22 – – – – – – – – – –0.65** –0.46** –0.66** –0.46** –0.28 –0.67** 0.41* –0.22 mM/L % % % % dS/m g – – – – – – – – – – – – – – – –0.76** 0.02 – – – – – – – – – – – – – – – – –0.06 mM/L Malic acid Fruit pH Glucose Citric acid Fructose Brix Fruit Plant Fruit height set Fresh fruit/ plant Dry matter content Fruit length Fruit width Seed/ fruit 1000 seed weight EC † TA † 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Parameters Table 2. Phenotypic correlations among the quantitative traits (morphological, agronomic and biochemical parameters) studied 16 17 Plant Genetic Resources Newsletter, 2000, No. 123 65 as well as for predicting new selection procedures for crop improvement (Cavicchi and Silvetti 1976). The pH, total titratable acidity and Brix are vital attributes with respect to the organoleptic quality of tomato fruit (Tigchelaar 1986; Mitchell et al. 1991; Agong 1995). On average, most landraces had a high number of biochemical attributes (Table 1b) and these characteristics are definitely useful where production tends to be for processing. Thus landraces may be a valuable source of germplasm for the improvement of processing tomatoes. The greater commercialization of these landraces would strongly motivate and economically empower small-scale farmers who possess a large portion of the germplasm. The lack of definitive classification based on the PCA strongly suggested closer phylogenetic relationship amongst the tomato accessions (Fig. 2). Fruit characters alone are unlikely to be suitable for evaluating tomato germplasm. The inclusion of more morphological, agronomic and biochemical traits would be appropriate, especially in a multi-trait selection programme for the improvement of horticultural characteristics (Broschat 1979). However, visual appraisal of germplasm during the vegetative and the reproductive phases confirmed genotypic variability within the germplasm (Fig. 1). These visual features were extremely helpful in genotypic differentiation of the landraces, such as the expression of stigma above the anther cone in accession 33, suggesting the close phylogenetic relationship of this landrace to the primitive progenitor of tomato (L. esculentum var. cerasiformie), known for its out-breeding tendency (Rick 1976; Alcazar-Esquinas 1981). From an evolutionary standpoint, if farmers have been practising methods which encourage intense inbreeding, it is very likely that rare genes will ultimately be expressed, thus exposing the wild phenotypes as observed in accession 33. Modern tomato cultivars comprise strongly self-pollinating types that have a limited chance of cross-pollination. As expected, correlation analyses revealed that fresh fruit yield was negatively associated to fruit number (Table 2). Thus, if small-scale farmers have been selecting for higher fruit number they might have done so at the expense of improving yields. Most tomato landraces had a higher num- Plant Genetic Resources Newsletter, 2000, No. 123 61 a b d c e f Fig. 1. Differentiation of the landraces from the market cultivars based on flower and fruit forms. Stigma protrusion from, and enclosure within, the anther cone as seen in ‘Nyaluo’ (a) and ‘Moneymaker’ (b) respectively. Diversity in fruit forms: ‘Moneymaker’ (c), ‘Cal J’ (d), Tindi (e) and ‘Nyanyandogo’ (f). ber of fruit per plant than the market cultivars, confirming their mostly inferior fresh fruit yield in comparison to the market cultivars, as evidenced elsewhere (Agong 1995). Over a long time period the high production of fruit in landraces can substantially benefit urban and peri-urban communities. Thus landraces can effectively be utilized under intensive and continuous tomato production systems. Most of the biochemical characters were negatively correlated to fresh fruit yield (Table 1b). Therefore, a breeding programme would sacrifice the larger fruit to obtain better quality, particularly when the main objective is to improve the processing quality (Agong et al. 1997). Electrical conductivity, Brix [%], pH value and total titratable acidity are used as criteria to judge the organoleptic and processing qualities of tomato and, therefore, require inclusion into breeding programmes (Mitchell et al. 1991; Agong et al. 1997). To conclude, based on current data, Kenyan tomato landraces are found to be suitable for production systems where processing is the commercial objective. Furthermore, due to their ability to produce a high quantity of fruit over time, their usefulness for improving tomato production under intensive and continuous systems cannot be ignored. However, modern cultivars produce higher fruit yield and will remain equally important for tomato improvement. In addition, due to the ever increasing rate at which tomato is introduced, there is a need to develop a reliable, faster and more affordable cultivar characterization procedure in order to safeguard small-scale producers. Acknowledgements This work was accomplished with the help of a financial grant from the German Academic Exchange Service (DAAD) to S.G. Fig. 2. Plot of the three principal components in determining the genotypic relatedness of the tomatoes based on fruit quantitative characters. g = Standard Kenyan tomato accessions; ? = West Kenyan tomato accessions; h= Central Kenyan tomato accessions; 6 = East/coastal Kenyan tomato accessions. Plant Genetic Resources Newsletter, 2000, No. 123 67 Agong. The authors also wish to thank Mr E. Sommer, Mr B. Arnemann and Mrs C. Methner for their unfailing technical support. References Agong, S.G. 1995. Collection and evaluation of Kenyan tomato landraces with special reference to salt and drought tolerance. Thesis, Justus-Liebig-Univ., Giessen. Agong, S.G., S. Schittenhelm and W. Friedt. 1997. Assessment of salt tolerance in the Kenyan tomato germplasm. Euphytica 95:57-66. Agong, S.G. and S. Schittenhelm. 1993. Collection of Lycopersicon esculentum germplasm in Kenya. Plant Genet. Resour. Newsl. 96:51-54 Alcazar-Esquinas, J.K. 1981. Genetic resources of tomatoes and wild relatives. International Board of Plant Genetic Resources, Rome, Italy. Broschat, T.K. 1979. Principal component analysis in horticultural research. Hortscience 14:114-117. Cavicchi, S. and E. Silvetti. 1976. Yield in tomato. I. Multiple regression between yield and yield components. Genet. Agric. 30:293-313. SAS Institute Inc. 1990. Version 6 SAS/STAT User’s Guide. Vol. I and II. Cary, NC. Kaemer, D., K. Weising, B. Beyermann, T. Börner, J.T. Epplen and G. Kahl. 1995. Oligonucleotide fingerprinting of tomato DNA. Plant Breed. 114:12-17. Mitchell, J.P., C. Shennen, S.R. Grattan and D.M. May. 1991. Tomato fruit yields and quality under water deficit and salinity. J Amer. Soc. Hort. Sci. 116:215-221. National Canners Association. 1968. Laboratory manual for food canners and processors, Vol. II. AVI Publishing Company, Westport, Conneticut, USA. Rick, C.M. 1976. Tomato. Pp 268-273 in Evolution of Crop Plants (N.W. Simmonds, ed.). Longman, London, UK. Rick, C.M. and M. Holle. 1990. Andean Lycopersicon esculentum var. cerasiformie: Genetic variation and its evolutionary significance. Econ. Bot. 44:69-78. Tigchelaar, E.C. 1986. Tomato breeding. In Breeding of Vegetable Crops (M.J. Basset, ed.). Avi Publishing Company, Westport, Conneticut, USA. Weber, W.E. and G. Wricke. 1994. Genetic markers in plant breeding. In Advances in Plant Breeding. J. Plant Breed, Suppl. 16. 68 Plant Genetic Resources Newsletter, 2000, No. 123 ARTICLE Plant Genetic Resources Newsletter, 2000, No. 123: 68 -77 Evaluation of the biological nitrogen-fixing ability of lupin (Lupinus L.) B.S. Kurlovich1*, L.T. Kartuzova1, B.M. Cheremisov1, T.A. Emeljanenko1, I.A. Tikhonovich2, A.P. Kozhemyakov2 and S.A. Tchetkova2 N.I. Vavilov Institute of Plant Industry, 190000, B. Morskaya str. 44, St. Petersburg, Russia. Present address (B.S.K.): Leppälaaksontie 5, as 1. 52420, Pellosniemi, Finland. Tel: +358 4051-38657 2 Research Institute for Agricultural Microbiology, 189620, St. Petersburg-Pushkin 8, Russia 1 Summary Résumé Resumen Evaluation of the biological nitrogen-fixing ability of lupin (Lupinus L.) Evaluation de l’aptitude du lupin (Lupinus L.) à fixer l’azote Evaluación de la capacidad del altramuz (Lupinus L.) para la fijación biológica de nitrógeno Accessions of lupin (Lupinus L.) with different origins (N=1050), drawn from the N.I. Vavilov Institute collection, were tested to reveal their nitrogen-fixing ability. Three treatments were used: (1) without inoculation of seed with Russian industrial strains of Bradyrhizobium sp. (Lupinus) and mineral nitrogen application (control), (2) with seed inoculation with Bradyrhizobium lupini (biological N), and (3) with an application of mineral nitrogen (mineral N). The results obtained demonstrated the different accessions of lupin with high nitrogen-fixation ability, the most effective nodule bacteria strains, and the complementary symbioses of plant and bacteria best able to accumulate nitrogen from the atmosphere. The results are used to discuss aspects of lupin diversity and suggest programmes for lupin selection for high-intensity symbiotic nitrogen fixation. On a testé des obtentions de lupin (Lupinus L.) d’origines différentes (N=1050), provenant de la collection de l’Institut N.I. Vavilov, en vue d’établir leur aptitude à fixer l’azote. On a utilisé trois traitements: 1) sans inoculation des semences avec des souches industrielles russes de Bradyrhizobium sp.(Lupinus) et l’application d’azote minéral (témoin), 2) avec inoculation des semences avec Bradyrhizobium lupini (N biologique), et 3) avec une application d’azote minéral (N minéral). Les résultats obtenus ont montré les différentes obtentions de lupin à forte aptitude à fixer l’azote, les souches bactériennes des nodosités très actives, et les symbioses complémentaires de plantes et de bactéries pouvant mieux accumuler l’azote atmosphérique. On s’appuie sur ces résultats pour examiner des aspects de la diversité des lupins et proposer des programmes de sélection des lupins pour une fixation symbiotique de l’azote à haute intensité. Keywords: Bradyrhizobium sp. (Lupinus), breeding, lupin diversity, Lupinus L., nitrogen fixation Se realizaron pruebas con accesiones de altramuz (Lupinus L.) de diversos orígenes (N=1050), tomadas de la colección del Instituto N.I. Vavilov, para observar su capacidad de fijación de nitrógeno. Se utilizaron tres tratamientos: 1) sin inoculación de semilla con variedades industriales rusas de Bradyrhizobium sp. (Lupinus) y aplicación de nitrógeno mineral (control), 2) con inoculación de semilla con Bradyrhizobium lupini (N biológico), y 3) con una aplicación de nitrógeno mineral (N mineral). Los resultados obtenidos pusieron de manifiesto las diferentes accesiones de altramuz con alta capacidad de fijación de nitrógeno, las variedades de bacterias nodulares más efectivas y las simbiosis complementarias de planta y bacteria más aptas para acumular nitrógeno de la atmósfera. A partir de los resultados se considera la diversidad del altramuz y se proponen programas de selección de altramuz con miras a una alta intensidad de fijación simbiótica de nitrógeno. Introduction Materials and methods The genus Lupinus L. has hundreds of species (Cowling 1994; Gladstones 1974, 1998), divided by origin into two clear groups (Kurlovich 1988; Kurlovich et al. 1995): one from the Mediterranean (subgen. Lupinus), and the other from America (subgen. Platycarpos (Wats.) Kurl.). The species are highly variable for the majority of characters, including their ability to fix nitrogen, which is determined by the efficiency of interaction between the lupin plants and the different nodule bacteria strains. The Lupinus genus is nodulated by the soil microorganism Bradyrhizobium sp. (Lupinus). Bradyrhizobia are encountered as microsymbionts of other leguminous crops (Argyrolobium, Lotus, Ornithopus, Acacia) of Mediterranean origin (Allen and Allen 1981; Jordan 1982; Legocki et al. 1997; Howieson et al. 1998). Many aspects of the Lupinus-Bradyrhizobium sp. (Lupinus) symbiosis have not been well investigated, especially from the point of view of genetic resources. The purpose of our work was to look at the diversity of lupin accessions in terms of biological nitrogenfixing ability, and relate them to the most effective nodule bacteria strains and complementary symbioses (plants and nodule bacteria strains) for nitrogen fixation. The material for research was made up of 1050 accessions from the N.I. Vavilov collection representing four species of lupin with various ecogeographical origins from the Mediterranean and 16 species from America. The principal accessions and species are specified in the tables in the Results section. Three treatments were used in evaluating the accessions: 1. Without inoculation of seed with Bradyrhizobium sp. (Lupinus) and mineral nitrogen application (control). 2. Seed inoculation with Bradyrhizobium lupini (biological N). Three widely used industrial Russian strains of Bradyrhizobium sp. (Lupinus) – 363A, 367 and 375A – produced in the All-Russian Research Institute for Agricultural Microbiology were used for inoculation. 3. Mineral nitrogen application (mineral N). For the mineral N treatment, ammoniac saltpeter was introduced at a rate of 60 kg active ingredient per hectare. The research was conducted between 1988 and 1998 in the field at Pavlovsk Experimental Station of the N.I. Vavilov Institute of Plant Industry, 20 km from St. Petersburg. The soil of the Plant Genetic Resources Newsletter, 2000, No. 123 69 plot was a derno-podzolic acid loam that had not been fertilized for several years. Accessions were tested at the same density of 30 plants/m2 under standardized conditions (Kurlovich et al. 1990, 1995, 1997). Nitrogenase activity was determined using Institute for Agricultural Microbiology recommendations (Alisova and Chunderova 1982). Results Growth and development of plants Inoculating seed with Bradyrhizobium sp. (Lupinus) did not increase germination or change the duration of the vegetative period. However, distinctions between plants of control variant (without inoculation with Bradyrhizobium lupini and mineral N application) and variant with inoculation were detected early. In the first case the colouring of lower leaves of plants was yellow, and higher leaves were yellow-green. In variants with application of biological and mineral N, all leaves were bright green. These colour differences were maintained up to the flowering phase. Subsequently, plants of the control acquired more green colouring, but colour intensity was much less than in inoculated plants. Root nodule formation White lupin (Lupinus albus L.) All control accessions had plants without nodules. More often, these plants were weaker and stunted. However, most of the treated plants had from one to seven large (maximum diam. 20 mm), dense and uneven nodules, located singly, on the side radicals. There were some exceptions to this pattern. On one (k507 from Egypt), nodules were also detected on the central radical and the side radicals; their size reached 23-28 mm in diameter. A large number of nodules (up to 45) were observed on plants of three samples (k-1930 from Sudan, and k-2589 and 2617 belonging to West-European agrogeotype); however, their size did not exceed 8 mm. The inoculation variant differed sharply in all morphological parameters from the control. Inoculated plants had a greater number of smooth nodules (2-7 mm diam.) placed evenly on all root systems. Number of nodules varied in different plants and samples, but in all cases there were many. of yellow lupin (k-2292 from Portugal), compared with the roots of a commercial variety (‘Akademichesky 1’) under inoculation with Bradyrhizobium sp. (Lupinus). Variety ‘Akademichesky 1’ was used in our experiment with yellow lupin as control. Of the accessions without inoculation and with mineral N application, samples k-2290 and k-2292 were the least responsive, and no nodules were formed. In cv. ‘Augy’ from Lithuania, nodules were densely located on all main radical roots. Nodules in the control were more protuberant than in experimental variants. Lupinus pilosus Murr. In the control the uniform distribution on the root system of separate nodules of a very large size (up to 15 mm) was characteristic. In the inoculated experimental variant, nodules were pinker and frequently located on a main root. Species of lupin from America The majority of investigated species of lupin from America had nodules on the root systems. The exceptions were three species (L. affinis Agardh, L. barkeri Lindl. and L. succulentus Dougl.), in which on the control the root system was poorly branched and without nodules. Depending on the species of lupin and source of N, nodules had unequal size, form and colour. The majority of species grew round nodules that surrounded main and side radicals, their sizes varied depending on species. Thus, on plants of L. paniculatus Desr. the half-couplings and couplings reached 20 mm. More often they were elastic, almost smooth thickenings, but sometimes protuberant. Plants of L. douglassii Agardh had marked, comblike couplings. The colour of nodules changed depending on species of lupin and treatments. Nodules occurred on all root systems (L. mutabilis Sweet.), or mainly on the main radical (L. pubescens Benth), or only on the side radicals (all species on mineral N treatment). In plants that received the mineral N, the root systems were strongly advanced. However the presence of ammoniac saltpeter decelerated development of nodules. They were fewer and placed mainly on the side radicals, more often as a bead-necklace formation. Narrow-leafed lupin (L. angustifolius L.) Accessions of this species also had the most nodules when inoculated with Bradyrhizobium sp. (Lupinus). Nodules were larger, placed as couplings and half-couplings. Yellow lupin (L. luteus L.) Inoculated accessions from Portugal, particularly k-2290 and k2292, had a large number of nodules. Figure 1 shows the root systems with nodules in the wild form Fig. 1. Root systems with nodules of the wild form of yellow lupin k-2292 from Portugal (right), compared with the roots of commercial variety ‘Akademichesky 1’ (left) under inoculation with Bradyrhizobium sp. (Lupinus). 70 Plant Genetic Resources Newsletter, 2000, No. 123 Nitrogenase activity One important parameter in the process of biological nitrogen fixation is the nitrogenase activity (Alisova and Chunderova 1982; Kurlovich et al. 1995; Van Kammen 1995). This parameter changes during the growth and development of plants (Table 1). In healthy plants the nitrogenase activity can be rather high up to the phase of green maturity of seed. However in plants infected with fusarium wilt (e.g. L. angustifolius), nitrogenase activity was sharply reduced in this phase. Nitrogenase activity is dependent on a number of factors: experimental treatments, species and varieties features (belonging to different geotype, ecotype or variety type), the presence of spontaneous populations of nodulating bacteria or industrial strains of rhizotorfin. Coefficient of variation (CV, %) of the Table 1. Intensity of nitrogenase activity in lupin through the stages of development (Mmol C2H4 h-1 plant-1) Stages of plant development VIR no. Species Vars., cvs., access. blossoming flowering of seed green maturity 2644 2603 1981 2949 2159 2267 193 L. albus L. L. albus L. L. angustifolius L. L. angustifolius L. L. mutabilis Sweet. L. ornatus Dougl. L. succulentus Dougl. Start Druzba Nemchinovsky 846 Danko - 5.91 9.39 4.89 8.16 49.87 9.21 0.06 8.20 9.94 8.10 5.77 87.21 11.95 0.06 4.74 18.30 0.87 0.35 86.95 12.80 0.05 Table 2. Nitrogenase activity in nodules of lupin (at flowering stage) with 375A industrial strain of Bradyrhizobium sp. (Lupinus) bacteria Nitrogenase activity (Mmol C2H4 h-1 plant-1) VIR no. Species Access., vars., cvs. Origin Lupins from Mediterranean (subgen. Lupinus) L. albus L. Start Russia 2644 2603 L. albus L. Druzba Ukraine L. angustifolius L. Danko Belarus 2949 L. angustifolius L. – France 2868 2866 L. angustifolius L. Apendrilon Greece L. angustifolius L. – Russia 1379 L. angustifolius L. – Russia 1980 1981 L. angustifolius L. Nemchinovsky 846 Russia L. angustifolius L. Timir–1 Russia 2664 L. luteus L. Augy Lithuania 2956 2298 L. luteus L. Cyt Poland L. luteus L. – Portugal 2289 L. luteus L. – Portugal 2291 2292 L. luteus L. – Portugal L. luteus L. – Spain 2865 L. luteus L. Kopylovsky Ukraine 2601 2649 L. luteus L. Foton Ukraine L. pilosus Murr. – Greece 304 Lupins from America (subgen. Platycarpos (Wats). Kurl.) 1572 L. affinis Agardh – Canada L. albococcineus Hort. – USA 2791 L. aridus Dougl. – Colombia 2543 1385 L. barkeri Lindl. – Mexico L. douglassi Agardh – Mexico 1425 L. elegans H.B.K. – Mexico 113 2110 L. hartwegii Lindl. – Mexico L. micranthus Dougl. – Canada 1733 L. mutabilis Sweet. – Peru 2159 1387 L. nanus Dougl. – Colombia L. ornatus Dougl. – USA 2267 L. paniculatus Dougl. – Canada 1960 208 L. pubescens Dougl. – Ecuador L. subcarnosus Hook – USA 2920 L. succulentus Dougl. – USA 193 1954 L. truncatus Nutt. – Mexico Avg. Min. Max. CV (%) 8.20 6.94 5.77 7.46 9.23 13.64 6.05 8.10 7.32 93.10 5.52 10.59 11.69 15.89 11.53 15.42 9.47 17.16 2.79 2.27 1.46 1.22 0.11 6.49 2.23 1.94 1.80 34.58 0.24 0.53 9.45 2.34 5.57 4.66 0.15 0.72 15.69 15.60 9.54 16.52 19.54 21.59 19.11 12.33 17.20 142.70 16.82 17.84 16.46 38.14 18.04 30.06 36.69 43.29 39.6 41.5 15.5 58.2 76.5 44.2 62.1 56.2 61.5 45.6 71.4 89.3 17.9 48.1 18.2 15.2 82.6 105.1 0.09 8.63 13.18 0.09 4.03 21.39 20.63 10.33 87.21 8.09 11.95 39.84 22.05 6.89 0.06 8.46 0.00 0.19 3.19 0.00 1.02 2.13 2.03 1.01 34.00 0.75 0.33 9.24 6.31 0.82 0.00 1.58 0.45 14.93 26.67 0.37 9.90 66.64 95.66 22.03 136.00 26.19 27.41 97.85 38.78 14.44 0.42 19.17 179.3 55.1 52.1 142.7 80.9 86.8 133.9 52.5 42.5 97.5 78.2 64.9 50.1 71.5 225.8 70.0 Plant Genetic Resources Newsletter, 2000, No. 123 71 level of nitrogenase activity ranged in species from 15.1 to 255.8% (Table 2). The highest nitrogenase activity was in L. mutabilis, the lowest in L. succulentus. Large variability of this parameter was recorded in the lupin species assessed: in yellow lupin ‘Augy’ (k-2956), nitrogenase activity reached 142.70 Mmol C2H4 h-1 plant-1 (Table 2), and in variety ‘Cyt’ (k-2398), belonging to the same species, it changed within the limits of 0.24-16.82 Mmol C2H4 h-1 plant-1. The high nitrogenase activity of variety ‘Augy’ promoted increased accumulation of dry weight of plants (Table 3). The positive correlation between nitrogenase activity and accumulation of dry substance, and sometimes also of protein content, has been established for many species of lupin. Accumulation of green and dry matter and N in plants The efficiency of symbiosis is best measured on the accumulation in plants of dry matter (DM) and nitrogen. Research has shown that the application of nodulating bacteria Bradyrhizobium sp. (Lupinus) in most cases increases the efficiency of plants. In some samples the increase in the total DM under inoculation with Bradyrhizobium sp. (Lupinus) bacteria was larger than under application of mineral N. White lupin (L. albus L.) Studied accessions responded differently to inoculation with B. lupini (Table 3). The maximum increase of green and dry weight (6.18 times) was measured in the sample from Greece (k- 2864), and the minimum (1.17-1.21 times) in variety ‘Tambovsky 86’ from Russia and sample k-682 from former Yugoslavia. In variety ‘Druzba’ from the Ukraine, in contrast, the total DM under application of Bradyrhizobium bacteria decreased. Other accessions that produced a good increase in crop yield (in comparison with control) when inoculated were: cvs. ‘Start’ (k2644) from Russia, ‘Olezka’ (k-2980) from Ukraine, accessions k-2989 and k-3250 from Portugal, ‘El Harrach-1’ (k-3110) from Algeria. Among the investigated samples, the greatest total DM in all treatments was from k-507 from Egypt, k-1930 from Sudan and k-2986 from Portugal. Narrow-leafed lupin (L. angustifolius) Most accessions showed increased plant productivity after application of B. lupini. The best efficiency was in: cvs. ‘Ladny’ and ‘Nemchinovsky 846’, ‘Determinant-2’ (k-3365) and ‘Determinant-3’ (k-3366) from Russia, k-3065 from Australia, ‘Apva’ (k2950), ‘Vika 65’ (k-2954), ‘DG-94’ (k-3351) and ‘DG-95’ (k3352) from Belarus, wild forms k-3076, k-3079 from Spain, k3083 from Portugal and k-3093 from Morroco (Fig. 2). So for example, application of B. lupini to the commercial Russian variety ‘Nemchinovsky 846’ increased the dry matter weight from 17.8 to 20.5 g. In this variety also the increase in accumulation of N was revealed (Table 4). In many cases increased plant productivity after inoculation with B. lupini was more significant than after application of mineral N. However, inoculation did not increase productivity of specimens and varieties from Palestine (k-288), Greece (k-2866) or of accessions from Australia (k2632, k-3062). Fig. 2. Effect of inoculation of Lupinus angustifolius L. (var. ‘Nemchinovsky 846’ from Russia, and var. ‘Yandee’ from Australia) with different strains of Bradyrhizobium sp. (Lupinus). 72 Plant Genetic Resources Newsletter, 2000, No. 123 Table 3. Accumulation of dry matter in plants (g/plant) on different backgrounds of nitrogen nutrition Treatment (DM in g/plant) VIR no. Species Access., vars., cvs. Lupins from Mediterranean (subgen. Lupinus) 3110 L. albus L. El Harrach–1 L. albus L. – 507 L. albus L. – 484 2589 L. albus L. Lublanc L. albus L. – 2617 L. albus L. – 2864 294 L. albus L. – L. albus L. – 1602 L. albus L. Line 802–15 2623 2986 L. albus L. 48B L. albus L. – 2989 L. albus L. – 3250 1596 L. albus L. Snezinka L. albus L. Start 2644 L. albus L. Tambovsky 86 2806 1930 L. albus L. – L. albus L. Druzba 2603 L. albus L. Olezka 2980 L. albus L. – 682 L. angustifolius L. Unicrop 2096 L. angustifolius L. Yandee 2632 L. angustifolius L. Line 75A/326 3061 L. angustifolius L. – 3062 L. angustifolius L. Line 75A/330 3064 L. angustifolius L. – 3065 2681 L. angustifolius L. Vada 10 L. angustifolius L. Apva 2950 L. angustifolius L. Jniven 2953 2954 L. angustifolius L. Vika 65 L. angustifolius L. DG–94 3351 L. angustifolius L. DG–95 3352 2866 L. angustifolius L. Apendrilon L. angustifolius L. Melkosemianny 1354 L. angustifolius L. – 3093 3094 L. angustifolius L. – L. angustifolius L. – 3097 L. angustifolius L. – 288 2570 L. angustifolius L. Mirela L. angustifolius L. Emir 2662 L. angustifolius L. Mut–1 2801 3083 L. angustifolius L. – L. angustifolius L. – 3084 L. angustifolius L. – 3087 3090 L. angustifolius L. – L. angustifolius L. Nemchinovsky 846 1981 L. angustifolius L. Ladny 2648 3365 L. angustifolius L. Determinant–2 L. angustifolius L. Determinant–3 3366 L. angustifolius L. Determinant–4 3367 3076 L. angustifolius L. – L. angustifolius L. – 3079 L. angustifolius L. – 3081 3082 L. angustifolius L. – L. luteus L. Akademichesky 1 1947 L. luteus L. Augy 2956 2398 L. luteus L. Cyt L. luteus L. – 2089 L. luteus L. – 2291 2290 L. luteus L. – L. luteus L. – 2292 L. luteus L. – 2865 Origin Control Biol. N Mineral N Algeria Egypt Ethiopia France France Greece Palestine Poland Portugal Portugal Portugal Portugal Russia Russia Russia Sudan Ukraine Ukraine Yugoslavia Australia Australia Australia Australia Australia Australia Belarus Belarus Belarus Belarus Belarus Belarus Greece Latvia Morocco Morocco Morocco Palestine Poland Poland Poland Portugal Portugal Portugal Portugal Russia Russia Russia Russia Russia Spain Spain Spain Spain Belarus Lithuania Poland Portugal Portugal Portugal Portugal Spain 17.9 30.3 30.1 14.6 14.5 15.0 25.1 22.6 27.0 29.5 19.6 20.1 16.8 15.1 15.0 30.2 20.7 19.6 19.4 16.7 16.8 22.5 15.0 20.1 19.2 15.2 19.2 17.9 19.0 24.5 25.6 2.1 20.5 28.0 26.5 27.5 18.2 19.5 16.8 22.2 16.2 15.1 17.6 16.3 17.8 13.5 16.8 16.5 15.5 18.5 19.0 14.6 14.3 16.2 24.2 6.6 19.5 13.8 9.7 10.1 9.3 26.5 33.6 32.9 16.2 16.3 85.1 28.2 24.2 29.5 32.6 25.9 26.9 18.2 20.9 15.3 33.6 20.0 26.8 19.9 18.5 15.9 24.6 14.2 23.8 23.6 20.3 22.1 19.5 21.0 27.8 28.3 2.1 22.6 32.1 30.1 31.0 16.5 24.8 21.3 24.6 18.5 17.3 18.5 18.5 20.5 17.8 20.4 19.3 18.2 22.4 23.2 16.2 16.0 18.5 20.7 10.2 17.5 12.6 19.6 20.1 13.0 25.2 33.0 33.5 16.0 16.0 25.2 28.0 24.5 30.0 30.0 25.1 27.0 18.5 21.0 17.3 34.1 22.5 25.1 19.5 20.0 20.2 25.0 22.0 24.0 25.0 20.0 20.0 20.2 20.0 28.0 28.0 6.5 24.0 30.5 30.0 32.5 24.2 22.3 20.5 25.0 19.0 17.0 19.1 18.0 20.8 17.2 20.0 19.5 19.0 22.0 24.8 19.0 17.2 Plant Genetic Resources Newsletter, 2000, No. 123 73 Treatment (DM in g/plant) VIR no. Species Access., vars., cvs. 2869 L. luteus L. – L. luteus L. – 3070 2000 L. luteus L. T–12 L. luteus L. Sojuz 2610 L. luteus L. Foton 2649 304 L. pilosus Murr. – Lupins from America (subgen. Platycarpos (Wats). Kurl.) L. affinis Agardh – 1572 2791 L. albococcineus Hort. – L. aridus Dougl. – 2543 L. barkeri Lindl. – 1385 1425 L. douglassi Agardh. – L. elegans H.B.K. – 113 L. hartwegii Lindl. – 2110 1733 L. micranthus Dougl. – L. mutabilis Sweet. – 2159 L. nanus Dougl. – 1387 2267 L. ornatus Dougl. – L. paniculatus Dougl. – 1960 L. pubescens Benth. – 208 2920 L. subcarnosus Hook. – L. succulentus Dougl. – 193 L. truncatus Nutt. – 1954 Origin Control Biol. N Spain Spain Sweden Ukraine Ukraine Greece 21.5 8.5 18.3 16.8 16.6 9.9 16.1 12.3 22.4 21.8 23.2 9.5 Canada USA Colombia Mexico Mexico Mexico Mexico Canada Peru Colombia USA Canada Ecuador USA USA Mexico 1.83 8.10 10.81 4.85 4.53 5.45 9.10 9.67 32.40 1.52 9.52 5.29 4.22 6.83 4.51 1.47 4.58 5.52 6.28 3.13 3.67 6.48 5.52 6.64 27.86 1.52 6.36 4.37 3.72 2.29 5.52 1.43 Mineral N 4.64 14.48 16.39 6.32 10.90 7.80 7.26 5.86 41.75 3.68 8.90 7.55 9.91 8.71 8.94 1.56 Table 4. The contents and accumulation of N in lupin plants with different N sources VIR no. Species Access., vars., cvs. Lupins from Mediterranean (subgen. Lupinus) 2398 L. luteus L. Cyt L. luteus L. Augy 2856 L. albus L. Druzba 2603 2644 L. albus L. Start L. angustifolius L. Danko 2649 L. angustifolius L. Nemchinovsky 846 1981 304 L. pilosus Murr. – Lupins from America (subgen. Platycarpos (Wats). Kurl.) L. mutabilis Sweet. – 2159 2543 L. aridus Dougl. – L. micranthus Dougl. – 1733 L. ornatus Dougl. – 2267 2791 L. albococcineus Hort. – L. hartwegii Lindl. – 2110 L. subcarnosus Hook. – 2920 1960 L. paniculatus Dougl. – L. pubescens Benth. – 208 L. elegans H.B.K. – 113 1425 L. douglassii Agardh. – L. barkeri Lindl. – 1385 L. succulentus Dougl. – 193 1387 L. nanus Dougl. – L. truncatus Nutt. – 1954 L. affinis Agardh. – 1572 N content of plants (%) Accumulation of N (mg/plant) Control Biol. N Control Biol. N 3.90 3.82 3.00 3.56 2.99 2.59 2.47 3.80 3.25 3.06 3.03 2.71 2.60 2.70 257 922 622 537 574 461 244 389 674 616 511 512 532 256 2.94 3.14 3.44 3.18 2.89 2.58 2.45 3.18 3.36 2.44 2.86 2.25 2.26 3.20 3.12 2.44 2.46 3.03 3.32 3.11 3.15 2.32 2.73 3.18 3.40 2.41 – 2.50 2.60 3.47 2.97 2.37 953 339 333 303 234 235 167 168 142 133 130 109 102 49 46 45 684 190 220 198 174 129 171 169 127 156 – 178 144 53 43 109 Yellow lupin (L. luteus) The greatest increase of dry matter under inoculation (99%) appeared in wild forms k-2290 and k-2292 from Portugal, and cv. ‘Cyt’ (k-2398) from Poland. ‘Cyt’ also showed an increase in accumulation of N (Table 4). Figures 3 and 4 show the size of Mineral N 2.83 3.32 3.52 3.47 3.05 2.65 2.58 3.07 3.30 2.85 3.20 2.60 2.73 2.89 3.11 2.46 Mineral N 1182 544 206 309 442 192 224 232 327 222 349 164 244 106 49 114 inoculated plants of the wild form k-2292 from Portugal (Fig. 3), and cv. ‘Cyt’ (k-2398) from Poland (Fig. 4), compared with the control. However, for cv. ‘Augy’ from Lithuania, and also samples k2289 and k-2291 from Portugal, the application of the bacterial 74 Plant Genetic Resources Newsletter, 2000, No. 123 strain 375A did not result in either an increase of dry matter or of N. Despite this, cv. ‘Augy’ had the greatest total DM of all investigated samples, both with inoculation of B. lupini and especially without it. Lupinus pilosus Murr. For inoculated accession k-304, green and dry weight did not increase (Table 3), although the contents and accumulation of N did increase (Table 4). Species of lupin from America These species were unresponsive to application of the nodulating bacteria strains 367A and 375A. Maximum accumulation of dry matter and N for almost all species from America occurred with application of mineral N. The exceptions were L. micranthus Dougl. and L. hartwegii Lindl., which were unresponsive to both inoculation with the industrial strain of bacteria, and the application of mineral N. The greatest amount of accumulated N in all three treatments was in L. mutabilis Sweet. Of interest as source material for selection for increased nitrogen-fixation ability are the following species: L. aridus Dougl., L. micranthus Dougl., L. ornatus Dougl., L. albococcineus Hort. In these experiments, also studied was the response of the fodder low-alkaloid multifoliate Washington lupin (L. polyphyllus Lindl.) to inoculation with strains of nodule bacteria in pure state and in combination with the biostimulator lentechnin and root diazotrops of the genus Arthrobacter (Table 5). Best results were received when inoculating the Washington lupin (cv. ‘Truvor’) with nodule bacteria strain 1625. Combining inoculation with seed treatment with lentechnin was also found to be efficient. Root diazotrops from Arthrobacter sp. did not show great efficiency in this combination. Fig. 3. Comparative sizes of plants of wild form k-2292 from Portugal (Lupinus luteus L.), inoculated with Bradyrhizobium lupini (right), and control variant (left). Discussion and conclusions As our research has shown, the evaluation of lupin accessions from different origins under treatments with biological and mineral N is rather effective. As a result of these experiments, the large differences in responses of various species and accessions of lupin to inoculation with nitrogen-fixing bacterial strains of Bradyrhizobium sp. (Lupinus) are revealed. The majority of investigated accessions showed rather high responsiveness to inoculation with commercial strains of Bradyrhizobium sp. The low or negative effects of inoculation in some accessions (especially from America) we explain by mismatch of the strains of bacteria used to plant genotypes. It testifies to the importance of creating highly complementary symbiotic pairs (plant and microorganisms), with the purpose of increasing responsiveness of plants to inoculation. It is necessary to realize that, without preliminary tests, the use of preparations of bacteria can be not only ineffective, but also can have negative results. On the other hand, the careful selection of varieties of lupin and complementary microsymbionts can increase efficiency of plants and fertility of soils, and also save expenditures on mineral fertilizers. One major condition for successful breeding of lupins with high nitrogen-fixing ability is the availability of genetically wellinvestigated and diverse materials, both plants and microorgan- Fig. 4. Comparative sizes of plants of yellow lupin cv. ‘Cyt’ from Poland inoculated with Bradyrhizobium lupini (right), and control variant (left). isms. Until now, more attention in research has been given to the second component of the symbiosis – nodulating bacteria. Research on increased efficiency of nitrogen fixation is put forward at the expense of selection of leguminous plants (Tchetkova and Tikhonovich 1986; Kurlovich et al. 1997). Furthermore, these components of a symbiosis are not equivalent, as the leguminous plant can exist and give good production Plant Genetic Resources Newsletter, 2000, No. 123 75 Table 5. Effects of nodule bacteria, biostimulator lentechnin (LT), and root diazotrops mizorin (MIZ) on activity of nitrogenase and productivity of fodder (sweet) Lupinus polyphyllus Lindl. (average for 1990–1995). Treatment Activity of nitrogenase (Mkmol C2H4 h-1 plant-1) Yield of green mass (kg/m²) Mass of seeds (g/plant) Control Strain 1610 Strain 1614 Strain 1625 Strain 1647 Inoculation + lentechnin (LT) Strain 1610 + LT Strain 1614 + LT Strain 1625 + LT Strain 1647 + LT Inoculation + mizorin (MIZ) Strain 1610 + MIZ Strain 1614 + MIZ Strain 1625 + MIZ Strain 1647 + MIZ SEM (standard error of mean) 80 172 55 336 166 50 190 30 275 1555 150 540 810 600 330 27 6.8 6.2 6.1 8.5 7.3 7.0 5.3 5.7 9.1 8.3 5.1 3.2 4.8 8.9 7.6 0.6 18.0 21.3 15.2 26.7 23.8 22.2 17.6 22.3 26.2 25.1 17.3 22.6 21.3 27.2 22.4 1.2 without microorganisms, for example with the expense of mineral fertilizers. However, it is necessary to execute genetic and breeding research in both directions. The selected prospective plant material should pass tests in treatments with the different strains of nodulating bacteria, and these new strains need to be tested on a rather large set of lupin accessions with different ecogeographical origins. The final stage of these operations should be the creation of effective and complementary symbioses (variety of plant and strain of bacteria), ensuring high symbiotic nitrogen-fixing ability. It is necessary to remark that the selection of lupin was begun long before the phenomenon of symbiotic nitrogen fixation was understood. Moreover, in those regions where wild lupin did not grow and was introduced, the natural soil populations of microorganisms very frequently did not contain high levels of active (and even specific) nodule bacteria. As a result, there was an unconscious selection of genotypes with low nitrogen-fixing ability. Thus, we now have varieties of lupin that react rather poorly to inoculation with bacteria, but are capable of providing a certain level of efficiency without inoculation. In this connection, one important problem now is the effective selection of bacterial strains suitable for existing commercial varieties of lupin, and the necessity of further selecting for a high intensity of symbiotic nitrogen fixation. As an example of a successful solution to this problem there can be carried out by us selection of the effective strain of bacteria (1625) for the perennial multifoliate fodder variety Washington (Lupinus polyphyllus Lindl.) from America. Given the results presented here, we conclude that efficient cultivation of Washington lupin is possible with highly efficient preparations of nodule bacteria strains, particularly in regions where lupin has not yet been cultivated. For each new variety of lupin it is necessary to select efficient nodule bacteria strains that correspond to the genotype of the plant. For creation of valuable genotypes of lupin it is necessary to take into account also the activity of the nitrogenase complex, which varies in the different forms of lupin from 0 to 100 Mmol C2H4 h-1 plant-1, and more. Even among plants of one sample there is variability of the given parameter (CV from 39.0 to 94.17%). Each sample represents a complex population consisting of plants with different levels of nitrogen-fixing activity. Selection of prospective plants should consider their levels of nitrogenase activity and its place in the selection process. Matching of the data on activity of the nitrogenase complex with parameters of accumulation of dry matter and protein content at lupin shows that the correlation between these parameters is frequently, though not always, significant. For example, the variety of yellow lupin ‘Augy’ from Lithuania has a very high nitrogenase activity (93.10 Mmol C2H4 h-1 plant-1), and the variety ‘Cyt’ from Poland has the lowest activity (5.52 Mmol C2H4 h-1 plant-1). As a result, the total dry matter at variety ‘Augy’ grown without N and without inoculation with nodulating bacteria is 24.2 g/plant, and for variety ‘Cyt’ only 6 g/plant. The same varieties grown with inoculation of nodulating bacteria (strain 376A) produced 20.7 and 10.2 g/plant, respectively. This example, except for the positive connection of two above-stated parameters, strongly illustrates the mismatch of strain 367A of nodule bacteria to the yellow lupin variety ‘Augy’. Thus, only complex record-keeping of all parameters describing the intensity of biological nitrogen-fixation in lupin allows us to evaluate the diversity in a species, to allocate effective material for selection, and also to develop many theoretical positions useful for the introduction and classification of a source material. In our research we were guided by Vavilov’s differential systemogeographic method of crop studies based on his Law of Homologous Series in hereditary variation and on the theory of the centres of origin (domestication) of cultivated plants (Vavilov 1920, 1935, 1987). This enabled us to not only disclose the diversity of forms, but also to reveal a series of regularities in their variation depending on the degree of cultivation, geographic environments and soil conditions. Our research has established that samples with high nitrogen-fixing ability are more often material from primary centres of forma- 76 Plant Genetic Resources Newsletter, 2000, No. 123 tion and origin of that or other species of lupin (Kurlovich 1988). An example is the yellow lupin accession k-2292 from Portugal, which is an updated centre of formation of yellow lupin (Vavilov 1935, 1987; Kurlovich et al. 1995). The high productivity of this accession under inoculation with Bradyrhizobium sp. (Lupinus) is confirmed not only by our data, but also by other research (Cheremisov 1991). Among accessions of white lupin from Greece (also a centre of origin and formation of this species) was the sample k-2864, also with high nitrogen-fixing ability. Our explanation for this is that the plants and their nodulating bacteria, during evolution at the centres of formation and domestication, became adapted to one another. When cultivated in new places, the plant did not thrive, but when inoculated with Bradyrhizobium sp. (Lupinus) bacteria in the new locations, the plants responded to give such high results. The indicated forms deserve the special attention as objects of genetic research, as the genes controlling nitrogen-fixing ability have jointly evolved with those of symbionts (Simarov and Tikhonovich 1985). The valuable forms of nitrogen-fixing lupins can be improved with mutagenesis (Sidorova et al. 1995). Practice shows that the best results can be achieved for optimum combination of mutagenesis and hybridization. For these purposes in hybridization it is necessary to involve mutants, wild and domesticated forms of lupin of various geographical origins. The results point to some areas of research that will allow the existing genetic resources of lupin to contribute further selection and breeding activities. Highly productive varieties of lupin could be created with increased abilities to nodulate and more efficient symbiotic nitrogen fixation, in conditions of low natural contents of soil mineral N. To do this, lupin varieties better able to form associations with the most effective strains of bacteria will need to be located. List of the best selected accessions of lupin, recommended as initial material for future breeding for high nitrogenfixing ability White lupin (L. albus) · Accessions ensuring an increase of a crop yield under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 363a) without application of mineral N (in comparison with control): cvs. ‘Start ‘ (k-’2644') from Russia, ‘Olezka’ (k-2980) from Ukraine accessions, k-2989 and k-3250 from Portugal, k-2864 from Greece, ‘El Harrach-1’ (k-3110) from Algeria. · Accessions with high activity of nitrogenase*: Lines 802-15 (k-2623) and 48B (k-7986) from Portugal, accessions k-507 from Egypt, ‘El Harrach-1’ (k-3110) from Egypt, k-1602 from Poland. · Accession described by increase of nitrogenase activity under artificial processing of Bradyrhizobium sp. (Lupinus) bacteria*: cvs. ‘Snezinka’ (k-1596) and ‘Tambovsky 86’ (k-2806) from Russia, k-1601 from Italy and ‘Lublanc’ (k-2589) from France. Narrow-leafed lupin (L. angustifolius) · Accessions ensuring an increase of a crop yield (in comparison with control) under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 367A) without application of mineral N: k-3065 from Australia, ‘Determinant-2’ (k-3365) and ‘Determinant-3’ (k-3366) from Russia, ‘Apva’ (k-2950), ‘Vika 65’ (k-2954), ‘DG94’ (k-3351) and ‘DG-95’ (k-3352) from Belarus, wild forms k3076, k-3079 from Spain, k-3083 from Portugal and k-3093 from Morocco. · Accessions ensuring an increase of green and dry matter under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 367A) also in a combination with application of mineral N*: cv. ‘Unicrop’ (k-2096), lines 75A/326 (k-3061), 75A/330 (k-3064) from Australia, cv. ‘Melkosemianny’ (k-1354) from Latvia, ‘Mut1’ (k-2803 from Poland, accessions ‘Vada 10’ (k-2681), ‘Jniven’ (k-2953) from Belarus, ‘Nemchinovsky 846’ (k-1981), ‘Determinant 4’ (k-3367) from Russia, wild forms k-3079, k-3081, k-3082 from Spain, k-3083, k-3084, k-3087, k-3090 from Portugal, k3093, k-3094, k- 3097 from Morocco. Yellow lupin (L. luteus) · Accessions ensuring an increase of a crop yield under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 375A) without application of mineral N: cvs. ‘Sojuz’ (k-2610), ‘Foton’ (k-2649) from Ukraine, ‘T-12’ (k-2000) from Sweden, k-2869 and k-3070 from Spain, wild form k-2292 from Portugal, cv. ‘Cyt’ (k-2398) from Poland, and cv. ‘Augy’ (k-2956) from Lithuania. · Accessions ensuring an increase of green and dry matter under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 375A) in a combination with application of mineral N*: cvs. ‘Sojuz’ (k-2610), ‘Foton’ (k-2649) from Ukraine, k-2869 from Spain, wild form k-2292 from Portugal. ** These data are the result of our previous investigation and publications in Russian (Kurlovich et al. 1995, 1997). Acknowledgements We wish to express our gratitude to Dr A.V. 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Advances in molecular characterization of the yellow lupin – Bradyrhizobium sp. (Lupinus) symbiotic model. Pp. 263-266 in Biological Fixation of Nitrogen for Ecology and Sustainable Agriculture (A.B. Legocki and H. Both, eds.). Proceedings NATO Advanced Research Workshop, Poznan, Poland, 10-14 September 1996. SpringerVerlag; Berlin; Germany. Sidorova, K.K., V.K. Shumny and L.P. Uzhintseva. 1995. Genetic experiments with pea mutants pending symbiosis studies. Pp. 475-478 in Nitrogen Fixation: Fundamentals and Application (I.A. Tikhonovich, N.A. Provorov and V.I. Romanov, eds.). Proceedings of the 10th International Congress on Nitrogen Fixation, St. Petersburg, Russia. Kluwer Academic Publishers Group, Dordrecht, Netherlands. Simarov, B.V. and I.A. Tikhonovich. 1985. Genetic basis of legume-rhizobial symbiosis. Mineral and biological nitrogen in Arable farming. Moscow, p. 199-203. Tchetkova, S.A. and I.A. Tikhonovich. 1986. Selection and use of the strains, effective on peas of the Afghani origin. Microbiology, Moscow 55:143-146. Van Kammen, A. 1995. The molecular development of nitrogen fixing root nodules. Pp. 9-14 in Nitrogen Fixation: Fundamentals and Application (I.A. Tikhonovich, N.A. Provorov and V.I. Romanov, eds.). Proceedings of the 10th International Congress on Nitrogen Fixation, St. Petersburg, Russia. Kluwer Academic Publishers Group, Dordrecht, Netherlands. Vavilov, N.I. 1920. The law of homologous series in hereditary variation. Pp. 3-20 in Proceedings, 3rd All Russian Breeding Congress, Saratov, Russia. Vavilov, N.I. 1935. Theoretical basis of plant breeding. MoscowLeningrad, 1:17-162. VIR, St. Petersburg, Russia. Vavilov, N.I. 1987. Origin and geography of cultivated plants. Leningrad, p. 15-42. VIR, St. Petersburg, Russia. 78 Plant Genetic Resources Newsletter, 2000, No. 123 Plant Genetic Resources Newsletter, 2000, No. 123: 68 -77 News and Notes Established terms and definitions on plant genetic resources and biological conservation in dispute There is a concern that some critical conservation concepts are inappropriately defined. An examination of the meaning of words used in conservation shows that some convey misleading definitions, i.e. distinct terms and distinct definitions are often applied to materials seemingly equal in nature. In particular, three select terms and their definitions – namely ‘genetic resource’, ‘biological resource’ and ‘biodiversity’ – have been shown to carry a number of incongruencies.1 Nonetheless, although flawed or redundant, these concepts (in particular, biological resource and biodiversity) are in the way of becoming established, supported as they are by parts of the scientific community and the political classes. The argument defended is that the establishment of defective concepts undermines the foundations of scientific thought itself. Seemingly, for example, the concept of biological resource is a circumscription rather than a definition and overlaps with that of genetic resource. Likewise, the term biodiversity sounds more like a conglomerate given the inclusion in the definition of biotic and abiotic elements. In the interest of truth, a wider discussion of this subject is much encouraged. 1 Allem, A.C. 1999. Dubious concepts in the Convention on Biological Diversity with special reference to genetic resource, biological resource, and biodiversity. In Second International Symposium on Genetic Resources for Latin America and the Caribbean, SIRGEALC 2 (A.S. Mariante and P.G. Bustamante, eds.). Brasília. Proceedings published in CD-ROM. Book Review Guide to Handling of Tropical and Subtropical Forest Seed Lars Schmidt 2000. Danida Forest Seed Centre, Krogerupveg 21, DK-3050 Humlebaek, Denmark ([email protected]). ISBN 87-982428-6-5. Available free. Fifteen years since the issuance of “A Guide to Forest Seed Handling, with special reference to the tropics” compiled by R.L. Willan and published jointly by DFSC and FAO, relevant progress has been achieved and new techniques and protocols for effective seed handling have become available. The present “Guide to Handling of Tropical and Subtropical Forest Seed” is meant to provide the reader with a comprehensive and updated review of efficient methods currently available for forest seed collection, handling and storage. As remarked in Chapter 1, problems related to seed procurement, processing and storage often represent a tangible restriction on the use of particular species. Scarcity of seed, inconstancy in seed production, short viability, difficulties in collecting and in removing barriers to germination are, among others, factors that limit the use of many tree species. In fact seedlings often tend to be sold at a fairly uniform price, no matter how much effort was involved in raising them (p. 7, quoted from Pedersen 1994). Consequently, only a handful of important genera and families are used in planting programmes, despite the increasing demand to broaden species diversity and to encourage the use of native trees. The application of the most suitable and cost-effective techniques for handling and storage of tropical forest seeds has the potential to bring more species into use. This Guide draws on the well-known capacity and experience gained by the Danida Forest Seed Centre over more than 30 years of continuous activity in this sector, particularly with the poorly understood tropical and subtropical species. It is written in a clear and direct style, while complying with sound scientific quality and providing a comprehensive list of reference at the end of each chapter. The outline of the book observes a logical sequence, starting with a general introduction to seed biology (Chapter 2) and then following the chronological order of seed handling: planning of seed collecting (Chapter 3), description of collecting phases (Chapter 4), processing (Chapter 6), seed storage and pretreatment (Chapters 8-9), and germination and seedling establishment (Chapter 10). Chapter 8 deals specifically with the effects of pests and pathogens on seed quality and gives useful hints on how to control them during the collecting, processing and storage phases, either through necessary precautions or through seed treatment. Seed testing (Chapter 11) is discussed from the perspective of the seed handler, thus describing what is measured during these tests, rather than how to conduct them, redirecting the reader to existing detailed guidelines for in-depth reading. Possible implications of seed handling on the genetic quality of seeds are discussed in Chapter 12. The author draws the Plant Genetic Resources Newsletter, 2000, No. 123 79 readers’ attention to possible caveats that may occur, in this respect, at any step in the seed-handling process. In fact, since most of the physical, morphological and physiological characteristics of the seeds differ according to family, each handling phase might result in a negative selection against seeds belonging to specific families rather than others. Therefore, part of or whole families may be lost during processing and handling, and the ratio between families in the final bulked seed lot or plants in the nursery may be different from the ratio between families in the seed lot before processing (p. 364, quoted from Lauridsen 1995). Chapter 13 provides details on the taxonomy, biology and management, in relation to nursery operation, of important microsymbionts for cultivated plants (e.g. mychorrizae, rhizobia and frankiae). There are specific cases, e.g. raising seedlings on a sterile medium or plantation on sites. Leonardo Petri Plant genetic resources in Below are some interesting Web addresses related to genetic resources. Please send information on other sites to the Managing Editor of the Newsletter at [email protected]. The addresses given here were all operating at the time of going to press (September 2000). Digital Taxonomy http://www.geocities.com/RainForest/Vines/8695/ Digital Taxonomy is an attempt to present a wide-ranging resource of information for biodiversity data management in the World Wide Web, and promote the effective use of computers for handling biological software development projects. The site provides a range of links on software, hardware, methodologies, standards, data sources, and projects related to biodiversity data management, covering DELTA, taxonomic databases, ecology, morphometrics, and phylogenetic analysis software, with emphasis on the exchange of free scientific software tools (preferably those including source code), computer techniques, and Internet addresses of developers and distributors of free bioinformatics software. The Expert Center for Taxonomic Identification http://www.eti.uva.nl The Expert Center for Taxonomic Identification (ETI) is a nongovernmental organisation (NGO) in operational relations with UNESCO. Its mission is to develop and produce scientific and educational computer-aided information systems, to improve the general access to, and to promote the broad use of taxonomic and biodiversity knowledge worldwide. ETI’s World Biodiversity Database, available on CD-ROM, provides a combination of scientific text, expert illustrations and professional photographs. ETI produces about 10 CD-ROM titles a year, packed with megabytes of reliable and thoroughly reviewed scientific information, all quickly accessible on CD-ROM. These CD-ROMs are distributed at the lowest possible (cost) price, in order to allow every scientist, including those in developing countries, to get access to information. The International Legume Database & Information Service (ILDIS) http://www.ildis.org/ The International Legume Database & Information Service (ILDIS) is an international project that aims to document and catalogue the world’s legume species diversity in a readily accessible form. Research groups in many countries are participating on a cooperative basis to pool information in the ILDIS World Database of Legumes, which is used to provide a worldwide information service through publications, electronic access and enquiry services. The ILDIS Co-ordinating Centre is based at the Centre for Plant Diversity and Systematics, School of Plant Sciences, The University of Reading, UK. ILDIS has regional centres in Argentina, Australia, Brazil, China, Colombia, India, Japan, Malawi, New Zealand, Russia and USA. These centres collect information from local herbaria, national botanists and from literature written in many different languages, making accessible a wealth of information that would otherwise remain hidden. Species 2000 http://www.sp2000.org/ Species 2000 aims at enumerating all known species of plants, animals, fungi and microbes on Earth as the baseline dataset for studies of global biodiversity. It will also provide a simple access point enabling users to link to other data systems for all groups of organisms, using direct species-links. Users worldwide will be able to verify the scientific name, status and classification of any 80 Plant Genetic Resources Newsletter, 2000, No. 123 known species via the Species Locator, which provides access to species checklist data drawn from an array of participating databases. The goal of Species 2000 is to provide a uniform and validated quality index of names of all known species for use as a practical tool. New Agriculturist online http://www.new-agri.co.uk/ New Agriculturist online provides monthly updates on the latest news and developments in tropical agriculture for a global audience. It also provides information on training courses and conferences for agriculturists, and on recent publications. Sections include: Points of view (children in agriculture, in the latest issue); Perspective; Focus on . . .(beekeeping, in the latest issue); In print; News briefs; In conference; On course; Developments; and Country profile. Recent books on PGR reviewed include “Encouraging Diversity: The conservation and development of plant genetic resources” (Conny Almekinders and Walter de Boef, eds), published by Intermediate Technology Publications, and “The Root Causes of Biodiversity Loss” (Alexander Wood, Pamela Stedman-Edwards and Johanna Mang, eds), published by WWF-International in association with Earthscan. The Internet Directory of Botany http://www.botany.net/IDB/ This would be a useful starting point for anyone seeking botanical information on the Internet. The Directory is an index to botanical information available on the Internet, compiled by Anthony R. Brach (Harvard University Herbarium, Cambridge; http://www.herbaria.harvard.edu/; Missouri Botanical Garden, St. Louis, USA; http://www.mobot.org/ ), Raino Lampinen (Botanical Museum, Finnish Museum of Natural History, University of Helsinki, Finland; http://www.helsinki.fi/ kmus/), Shunguo Liu (SHL Systemhouse, Edmonton, Canada) and Keith McCree (Oakridge, Oregon). Links are organised by the following categories: Arboreta and Botanical Gardens; Botanical Societies, International Botanical Organizations; Biologists’ Addresses; Botanical Museums, Herbaria, Natural History Museums; Checklists and Floras, Taxonomical Databases, Vegetation; Conservation and Threatened Plants; Economic Botany, Ethnobotany; Gardening; Images; Journals, Book, Literature Databases, Publishers; Link Collections, Resource Guides; Listservers and Newsgroups; Lower Plants and Fungi; Other Resources; Paleobotany, Palynology, Pollen; Software; University Departments, Other Institutes; and Vascular Plant Families. Plant Genetic Resources Newsletter Bulletin des ressources phytogénétiques Boletín de Recursos Fitogenéticos Aims and scope Domaine d’intérêt Objetivos y temas The Plant Genetic Resources Newsletter publishes papers in English, French or Spanish, dealing with the genetic resources of useful plants, resulting from new work, historical study, review and criticism in genetic diversity, ethnobotanical and ecogeographical surveying, herbarium studies, collecting, characterization and evaluation, documentation, conservation, and genebank practice. Le Bulletin des ressources phytogénétiques publie des articles en anglais, en espagnol et en français, sur les ressources génétiques de plantes utiles, fruit de nouvelles recherches, d’études historiques, d’examens et de critiques concernant la diversité génétique, d’études ethnobotaniques et écogéographiques, d’études d’herbiers, d’activités de collecte, de caractérisation et d’évaluation, de documentation, de conservation et les pratiques des banques de gènes. El Noticiario de Recursos Fitogenéticos publica documentos en inglés, francés y español que tratan de los recursos genéticos de plantas útiles, fruto de nuevos trabajos, estudios históricos, revisiones y análisis críticos relacionados con la diversidad genética, investigaciones etnobotánicas y ecogeográficas, estudios de herbarios, actividades de colección, caracterización y evaluación, documentación, conservación, y prácticas en bancos de germoplasma. Parrainage Dirección Le Bulletin des ressources phytogénétiques est publié sous les auspices de l’Institut international des ressources phytogénétiques (IPGRI) et de la Division de la production végétale et de la protection des plantes de l’Organisation des Nations Unies pour l’alimentation et l’agriculture (FAO) El Noticiario de Recursos Fitogenéticos se publica bajo los auspicios conjuntos del Instituto Internacional de Recursos Fitogenéticos y la Dirección de Producción y Protección Vegetal de la Organización de las Naciones Unidas para la Agricultura y la Alimentación. Distribution Distribución Le Bulletin des ressources phytogénétiques paraît une fois par an en un volume regroupant quatre numéros publiés en mars, juin, septembre et décembre. Il est distribué gratuitement aux bibliothèques des banques de gènes, universités, services gouvernementaux, instituts de recherche, etc. s’intéressant aux ressources phytogénétiques. Il est aussi envoyé sur demande à tous ceux pouvant démontrer qu’ils ont besoin d’un exemplaire personnel de cette publication. El Noticiario de Recursos Fitogenéticos aparece como un volumen anual compuesto por cuatro números, que se publican en marzo, junio, septiembre y diciembre. Se distribuye gratuitamente a las bibliotecas de bancos de germoplasma, facultades universitarias y servicios gubernamentales, centros de investigación, etc. que se interesan en los recursos fitogenéticos. También pueden obtener este noticiario las personas que demuestren necesitar una copia personal. Articles Types de documents publiés Tipos de documentos An article will publish the results of new and original work that makes a significant contribution to the knowledge of the subject area that the article deals with. Articles, which should be of a reasonable length, will be considered by the Editorial Committee for scope and suitability, then assessed by an expert referee for scientific content and validity. Articles Artículos Un article contient les résultats de travaux nouveaux et originaux qui apportent une contribution importante à la connaissance du sujet dont traite l’article. Les articles, qui doivent être d’une longueur raisonnable, sont d’abord examinés par le Comité de rédaction qui en évalue la portée et la validité, puis par un expert qui en examine le contenu et l’intérêt scientifiques. Los artículos divulgarán los resultados de trabajos nuevos y originales que contribuyan de modo importante al conocimiento del tema tratado. Dichos artículos, que deberán tener una longitud razonable, serán examinados por el Comité de Redacción en cuanto a su pertinencia e idoneidad y posteriormente un experto juzgará su contenido y validez científicos. A short communication will report results, in an abbreviated form, of work of interest to the plant genetic resources community. Short communications in particular will contain accounts of germplasm acquisition missions. The papers will be assessed by an expert referee for scientific content and validity. Brèves communications Comunicaciones breves On entend par brève communication un texte contenant, sous une forme abrégée, les résultats de travaux présentant un intêrêt pour tous ceux qui s’occupent de ressources phytogénétiques. Elle contient en particulier des comptes rendus des missions d’acquisition de matériel génétique. Las comunicaciones breves informarán de modo conciso sobre los resultados de trabajos de interés para las personas que se ocupan de los recursos fitogenéticos. Las comunicaciones breves incluirán, en particular, resúmenes sobre las misiones de adquisición de germoplasma. Other papers Autres documents Otros documentos The Plant Genetic Resources Newsletter will publish other forms of reports such as discussion papers, critical reviews, and papers discussing current issues within plant genetic resources. Book reviews will be printed, as well as a News and Notes section. Suggestions for books to review are invited, as are contributions to News and Notes. Le Bulletin des ressources phytogénétiques publie d’autres types de rapport tels que des documents de synthèse, des études critiques et des articles commentant des problèmes actuels concernant les ressources phytogénétiques. Le Bulletin publie une revue de livres ainsi qu’une section intitulée Nouvelles et Notes. Les auteurs sont invités à envoyer leurs suggestions pour les livres à passer en revue ainsi que des contributions aux Nouvelles et Notes. El Noticiario de Recursos Fitogenéticos publicará otros tipos de informes, como documentos de trabajo, análisis críticos, y documentos que examinen cuestiones de actualidad relacionadas con los recursos fitogenéticos. El Noticiario publicará una reseña de libros así como una sección de Noticias y Notas. Las propuestas de libros para reseñar y las contribuciones a la sección de Noticias y Notas serán bien acogidas. Présentation Los documentos deben entregarse, incialmente, en forma de texto mecanografiado o a través del correo electrónico. La versión final debe presentarse como un archivo de correo electrónico o en disquete compatible con el sistema operativo Windows. Los manuscritos para publicar y otras comunicaciones sobre asuntos relativos a la redacción deberán dirigirse a la Oficina de Redacción del IPGRI. Management The Plant Genetic Resources Newsletter is published under the joint auspices of the International Plant Genetic Resources Institute (IPGRI) and the Plant Production and Protection Division of the Food and Agriculture Organization of the United Nations (FAO). Availability The Plant Genetic Resources Newsletter appears as one volume per year, made up of four issues, published in March, June, September and December. Plant Genetic Resources Newsletter is available free of charge to interested libraries of genebanks, university and government departments, research institutions, etc. The periodical may also be made available to individuals who can show that they have a need for a personal copy of the publication. Types of paper Short communications Submission In the first instance papers may be submitted in typescript form or as an Email message. The final version may be submitted as an Email file or as a Windows-readable file on diskette. Manuscripts submitted for publication and other communications on editorial matters should be addressed to IPGRI's Editorial and Publications Unit. En premier lieu, les documents doivent être soumis dactylographiés ou par courrier électronique. La version définitive doit être présentée en fichier de courrier électronique ou sur disquettes compatibles Windows. Prière d’adresser les manuscrits présentés pour être publiés et d’autres communications sur des questions de rédaction au Bureau de rédaction de l'IPGRI. Presentación Plant Genetic Resources Newsletter No. 123, September 2000 Contents Articles Utilization of germplasm conserved in Chinese national genebanks - a survey G. Weidong, J. Fang, D. Zheng, Y. Li, X. Lu (China), R.V. Rao (Malaysia), T. Hodgkin (Italy) and Z. Zongwen (China) .......................................................................................................................................... 1 The use of home gardens as a component of the national strategy for the in situ conservation of plant genetic resources in Cuba L. Castiñeiras, Z.F. Mayor, S. Pico and E. Salinas (Cuba) ................................................................................... 9 Ethnobotanical testimony on the ancestors of cassava (Manihot esculenta Crantz subsp. esculenta) A.C. Allem (Brazil) ................................................................................................................................................ 19 Reincorporación del fríjol carauta (Phaseolus lunatus L.) a la agricultura tradicional en el resguardo indígena de San Andrés de Sotavento (Córdoba, Colombia) G.P. Ballesteros, A.G. Torres y M. Barrera (Colombia) ...................................................................................... 23 El conocimiento local y su contribución al trabajo de rescate, conservación y uso de las semillas de Phaseolus y Vigna en las vegas del Río Orinoco, Estado Guárico, Venezuela A. Bolivar, M. Lopez, M. D'Goveia y M. Gutiérrez (Venezuela) .......................................................................... 28 A network for the management of genetic resources of maize populations in France J. Dallard, P. Noël, B. Gouesnard and A. Boyat (France) ................................................................................... 35 Caracterización por cianogénesis de una colección de trébol blanco (Trifolium repens L.) en Pergamino, Argentina E.M. Pagano y B.S. Rosso (Argentina) ............................................................................................................... 41 Conservation et valorisation des ressources génétiques fourragères et pastorales du Nord Tunisien M. Chakroun et M. Zouaghi (Tunisia) ................................................................................................................... 46 Resistance to powdery mildew in barley (Hordeum vulgare L.) landraces from Egypt J.H. Czembor (Poland) ......................................................................................................................................... 52 Genotypic variation of Kenyan tomato (Lycopersicon esculentum L.) germplasm S.G. Agong (Kenya), S. Schittenhelm and W. Friedt (Germany) ........................................................................ 61 Evaluation of the biological nitrogen-fixing ability of lupin (Lupinus L.) B.S. Kurlovich, L.T. Kartuzova, B.M. Cheremisov, T.A. Emeljanenko, I.A. Tikhonovich, A.P. Kozhemyakov and S.A. Tchetkova (Russia) .................................................................................... 68 News and Notes ................................................................................................................................................... 78 Book Review ........................................................................................................................................................ 78 Cyberspace .......................................................................................................................................................... 79