Editorial - Fedepalma

Editorial
Clones en palma de aceite: sí, pero con condiciones
La tecnología p a r a la obtención y multiplicación
de clones por fin e s t á disponible p a r a su u s o comercial por lo que productores de semilla y cultiva
dores e s t á n d e s a r r o l l a n d o m u c h a actividad e n
torno a la producción, v e n t a y s i e m b r a de clones
de p a l m a de aceite. Por e s t a razón, es i m p o r t a n t e
q u e los p a l m i c u l t o r e s t e n g a n u n c o n o c i m i e n t o
claro s o b r e q u é s o n los c l o n e s y c u á n d o d e b e
utilizarse e s t a semilla p a r a las n u e v a s s i e m b r a s
o p a r a la renovación de s u s cultivos.
La propagación o multiplicación comercial de
p l a n t a s p u e d e h a c e r s e por m é t o d o s s e x u a l e s o
a s e x u a l e s . Por l o s p r i m e r o s s e p r o p a g a n p o r
ejemplo la p a l m a de aceite, el arroz, la soya y el
trigo; y por los s e g u n d o s , la p a p a , la y u c a y el
p l á t a n o . C a d a u n o d e ellos tiene s u s v e n t a j a s
d e s d e el p u n t o de vista comercial. Por el método
sexual es m á s fácil p r o d u c i r semilla y p a r a su
certificación comercial b a s t a s i m p l e m e n t e con
multiplicar la variedad y eliminar d u r a n t e e s a
propagación las p l a n t a s fuera de tipo. En el c a s o
de la propagación asexual es un poco m á s complejo, p u e s por este medio se p u e d e n multiplicar vir u s u otros o r g a n i s m o s q u e p u e d e n d e g e n e r a r la
p l a n t a y. p o r t a n t o , se debe r e c u r r i r a multiplicación en lotes a i s l a d o s o u s a r m é t o d o s como el de
la multiplicación in vitro y multiplicación r á p i d a
q u e g a r a n t i c e n la s a n i d a d del material p r o d u c i d o .
Los m é t o d o s de m e j o r a m i e n t o s e l e c c i o n a d o s
p a r a la producción de n u e v a s variedades d e p e n d e n
del s i s t e m a de propagación de la p l a n t a y de s u s
características de polinización y su conformación
genética. El mejoramiento en p l a n t a s q u e se a u t o polinizan n o r m a l m e n t e , como el arroz, requiere
procedimientos e n los c u a l e s s e p l a n e a u n a serie
de c r u z a m i e n t o s y u n a vez q u e se identifica la
p l a n t a d e s e a d a , é s t a s e deja a u t o f e c u n d a r por
cinco o seis generaciones para eliminar las
plantas fuera de tipo. Habitualmente la producción
de u n a variedad mejorada de este tipo de material d u r a alrededor de cinco a seis a ñ o s . En p l a n t a s
de polinización c r u z a d a , como el maíz y la p a l m a
de aceite, lo q u e se b u s c a es u n a mezcla de
genotipos q u e p o s e a n características morfológicas
y fisiológicas s e m e j a n t e s .
Los m a t e r i a l e s o b t e n i d o s d e e s t a m a n e r a
tienen plasticidad ambiental y amplia a d a p t a c i ó n ,
s u p e r i o r a las de v a r i e d a d e s q u e n a t u r a l m e n t e
se autopolinizan. Sin embargo, p a r a la obtención
de un m á x i m o vigor y u n a mayor producción en
este tipo de p l a n t a s se requiere el c r u z a m i e n t o
de dos p a d r e s c o n t r a s t a n t e s , pero lo q u e se g a n a
en p r o d u c c i ó n se pierde en r a n g o de a d a p t a c i ó n .
En el c a s o del maíz, se tiene materiales híbridos
que p r e s e n t a n u n a alta producción en á r e a s
r e s t r i n g i d a s y v a r i e d a d e s c o n f o r m a d a s por u n a
mezcla d e genotipos, con u n r e n d i m i e n t o p r o m e dio inferior al de los híbridos pero con u n a amplia
a d a p t a c i ó n a diferentes condiciones a m b i e n t a l e s .
Ello, p o r e s t a r c o n f o r m a d a s por u n a mezcla de
genotipos, c a d a u n o d e los c u a l e s p u e d e tener
d i f e r e n t e g r a d o de a d a p t a c i ó n y r e s i s t e n c i a a
e n f e r m e d a d e s y / o plagas, c a r a c t e r í s t i c a s q u e son
l i m i t a d a s en los m a t e r i a l e s h í b r i d o s , cuyo
c o m p o n e n t e genético e s m á s restringido.
La p a l m a de aceite es u n a p l a n t a de polinización c r u z a d a de a m p l i a diversidad genética. Se
h a c o m p r o b a d o q u e p r á c t i c a m e n t e cada p l a n t a
tiene u n a composición genética diferente, a u n q u e
los m a t e r i a l e s comerciales en la mayoría de los
c a s o s s e ven fenotípicamente m u y homogéneos.
El mejoramiento tradicional de los cultivos perennes como éste se ha orientado principalmente
h a c i a la selección de p l a n t a s con características
d e s e a b l e s , seguido de c r u z a m i e n t o s e n t r e sí con
el fin de o b t e n e r p o b l a c i o n e s s u p e r i o r e s , p a r a
p o s t e r i o r m e n t e c r u z a r l a s y c o m p a r a r s u s progenies en diferentes a m b i e n t e s . Así, finalmente de
ellas se seleccionan materiales comerciales con
buenas características agronómicas y buena
adaptación.
E s t e procedimiento p u e d e d u r a r de veinte a
veinticinco a ñ o s y es lo q u e h a s t a a h o r a se ha
venido realizando en p a l m a de aceite. Con el desarrollo de la ciencia se h a n logrado establecer
u n a s h e r r a m i e n t a s q u e agilizan e n p a r t e e s t e
proceso tradicional de mejoramiento. Una de ellas
es la biotecnología, q u e se p u e d e emplear p a r a
identificar genotipos d e s e a b l e s en c u a l q u i e r a de
l a s e t a p a s del m e j o r a m i e n t o tradicional. Como
c o m p l e m e n t o a e s t a identificación, d e s p u é s de
varios a ñ o s d e i n t e n s o trabajo e n t r e diferentes
g r u p o s de investigación se logró obtener y producir
e n forma c o m e r c i a l u n g e n o t i p o d e p a l m a d e
aceite, lo que comercialmente se denomina
PALMAS - Vol. 26 No. 2, 2005
5
"clon . c u y a m e t o d o l o g í a d e p r o d u c c i ó n e s
específica p a r a c a d a p l a n t a q u e se d e s e e clonar.
L a g r a n diferencia e n t r e u t i l i z a r c l o n e s e n
p a l m a de aceite en relación con semilla sexual,
como se ha venido haciendo h a s t a a h o r a , es q u e
el clon es un solo genotipo y la semilla comercial
q u e se está s e m b r a n d o hoy día es u n a mezcla de
genotipos diferentes. Esto h a c e q u e en la i n t e r a c ción genotipo por a m b i e n t e s e a m u c h í s i m o m e n o r
el efecto del a m b i e n t e en aquellos materiales q u e
se multiplican por semilla, por c u a n t o los diferentes genotipos q u e lo conforman funcionan como
búfer, minimizando en m u c h o s c a s o s el efecto de
las condiciones de suelo y clima en los c u a l e s son
s e m b r a d o s los diferentes materiales. Sin embargo,
e s a c a p a c i d a d búfer q u e t i e n e n e s a s s e m i l l a s
c u a n d o se utiliza el clon p r á c t i c a m e n t e se pierde
y su rango de a d a p t a c i ó n se minimiza.
La clonación en p a l m a de aceite d e b e s e r utilizada u n a vez identificados los mejores m a t e r i a l e s
e n u n p r o g r a m a d e mejoramiento e n u n a m b i e n t e
d a d o . Con e s t o s m a t e r i a l e s , m u l t i p l i c a d o s e n
forma masiva, s e m b r a d o s en los a m b i e n t e s p a r a
los c u a l e s fueron seleccionados, t e ó r i c a m e n t e se
podrían o b t e n e r mejores r e n d i m i e n t o s de aceite
por hectárea, siempre y c u a n d o se les dé el manejo
agronómico requerido. De e s a m a n e r a podría allan a r s e el c a m i n o h a c i a la a g r i c u l t u r a de precisión
p a r a acercarse al potencial teórico de 18 toneladas
de aceite por h e c t á r e a . Hay q u e tener p r e s e n t e
q u e si e s t o s clones que se h a n seleccionado bajo
determinadas condiciones agro-climáticas se
siembran en otras condiciones que no son
aquellas en las cuales se seleccionaron, s u s posibilidades de éxito son r e m o t a s .
Entonces se podría preguntar: ¿ c u á n d o es
seguro utilizar clones? Es s e g u r o hacerlo c u a n d o
detrás de su producción hay un programa de mejor a m i e n t o a largo plazo, sostenible y organizado.
C u a n d o éste c u e n t a con un b a n c o de germoplasma
de amplia diversidad genética p a r a poder s a c a r
genotipos d e s e a b l e s y realice u n a selección de
progenitores sometidos a diferentes condiciones
agro-climáticas. Cuando se hacen p r u e b a s de
progenie en las principales z o n a s p a l m e r a s en las
q u e p o t e n c i a l m e n t e se iría a s e m b r a r el m a t e rial. de tal m a n e r a que p a r a cada z o n a se p u e d a n
identificar aquellas p l a n t a s s u p e r i o r e s que
deberían ser clonadas y multiplicadas, para
posteriormente s e m b r a r l a s en los sitios d o n d e la
interacción genotipo-ambiente se maximice y el
genotipo se p u e d a expresar al máximo. Todo esto
debe ir c o m p l e m e n t a d o con un p r o g r a m a de clo-
6
PALMAS
n a c i ó n l o s u f i c i e n t e m e n t e s e g u r o p a r a evitar
anormalidades, muy frecuentes cuando no se
ulili/.a la tecnología a p r o p i a d a .
La Corporación Centro de Investigación p a r a
la P a l m a de Aceite (Cenipalma), d e n t r o de su
p r o g r a m a de producción de v a r i e d a d e s de p a l m a
de alto r e n d i m i e n t o de aceite, a d a p t a d a s a las
p r i n c i p a l e s z o n a s p a l m e r a s del p a í s y con
tolerancia a p l a g a s y e n f e r m e d a d e s q u e predom i n a n en c a d a zona, ha iniciado con el apoyo de
Colciencias. la i m p l a n t a c i ó n del laboratorio de
cultivo de tejidos p a r a la producción de clones.
Hay q u e t e n e r m u y claro q u e el objetivo principal de la i n v e s t i g a c i ó n en m e j o r a m i e n t o de
C e n i p a l m a es lograr q u e los palmicultores colomb i a n o s d i s p o n g a n del mejor material p a r a c a d a
u n a de s u s condiciones agro-climáticas y, en ese
orden de ideas, apoyar a los productores nacionales
de semilla y a las p l a n t a c i o n e s q u e deseen producir s u s propios materiales. C e n i p a l m a está e n
el proceso de zonificar desde el p u n t o de vista agroclimático las diferentes á r e a s p a l m e r a s colombian a s con el objeto de establecer las p r u e b a s de progenie y p r u e b a s regionales, p a r a q u e los genotipos
q u e mejor s e c o m p o r t e n e n c a d a u n a d e ellas
p u e d a n s e r multiplicados sexual o clonalmente
p a r a su utilización c o m e r c i a l . Con b a s e en la
clasificación agro-climática, se d e s a r r o l l a r á n las
prácticas a g r o n ó m i c a s q u e se a d a p t e n no sólo a
las condiciones edafo-clilmáticas, sino t a m b i é n
a los genotipos identificados p a r a c a d a zona.
Desde 1996 se inició la evaluación de materiales D u r a s e m b r a d o s e n las diferentes z o n a s
palmeras; ya existen a l g u n o s promisorios y la idea
es c o n c e n t r a r en poblaciones las características
d e s e a b l e s de e s a s p l a n t a s q u e se e s t á n seleccion a n d o , realizar y obtener c r u z a m i e n t o s Ténera,
y h a c e r las p r u e b a s regionales y de progenie, p a r a
identificar los i n d i v i d u o s m á s s o b r e s a l i e n t e s ,
m u l t i p l i c a r l o s c l o n a l m e n t e y utilizarlos en las
n u e v a s s i e m b r a s o r e n o v a c i ó n de l a s a c t u a l e s
p l a n t a c i o n e s . De la m i s m a forma, C e n i p a l m a
a s p i r a poder p r e s t a r el servicio a aquellos productores colombianos de semilla que estén
i n t e r e s a d o s en clonar material p a r a su posterior
multiplicación y venta a los palmicultores.
Igualmente, espera hacer alianzas en el país y
en el exterior p a r a poder agilizar la obtención de
materiales q u e serán, en el futuro, la b a s e de la
a g r i c u l t u r a de precisión de la p a l m a de aceite
colombiana, lo que representaría la posibilidad de
m a n t e n e r la competitividad del s e c t o r a nivel
mundial.
Editorial
Oil Palm Clones: Yes, but with Conditions
The technology to obtain and propagate clones
is finally available for commercial use. Seed producers and palm growers are very active now
around the production, sale and planting of oil
palm clones. For this reason, it is important for
palm growers to have a clear understanding about
clones and when to use them in a new planting
or a plantation renewal
Commercial plant propagation can be done by
either sexual or asexual methods. Sexual propagation is used, for example, in oil palm, rice, soybean and wheat, and asexual propagation in potato, yucca and banana. From the commercial
perspective, each method h a s its advantages.
With the sexual method it is easier to produce
seeds, and for the commercial certification, you
only need to practice a careful roguing and selection to remove off-type plants. The asexual propagation is a little more complex. With this system,
there exists the possibility to propagate viruses
or other organisms that can affect the plant.
Therefore, the propagation must be done in isolated lots or through in vitro techniques, so as to
guarantee the health of the planting material.
Plant breeding methods for the production of
new varieties depend on the plant's reproduction
system, pollination characteristics and genetic
makeup. A breeding program for self-pollinated
plants, such as rice, requires a series of crossbreeding, and, once the desired plant is identified, it is allowed to self-pollinate for five or six
generations in order to eliminate off-type plants.
Usually, it takes five or six years to obtain a new
variety of this type of material. In cross-pollinated
plants, such as corn and oil palm, the idea is to
find a mixture of genotypes with similar morphologic and physiologic features.
Materials obtained in this way have environmental plasticity and wide adaptation, better than
that of naturally self-pollinated varieties. However,
to obtain maximum vigor and better yield in this
type of plants, crosses between contrasting parents are required; however, what is gained in yield
can be lost in adaptation range. In the case of corn,
there are high-yield hybrid materials in restricted
areas and mixed genotype varieties, with an average yield lower than that of the hybrids, but better adaptability to different environmental conditions, as the different genotypes may have different degrees of adaptation and resistance to diseases a n d / o r pests. Because of the more restricted
genetic makeup, these characteristics are very
limited in hybrid planting materials.
The oil palm is a cross-pollinated plant with
wide genetic variability. Studies have shown that
basically each plant has a different genetic makeup, although most commercial materials look
phenotypically similar. Plant breeding programs
for perennial crops have been traditionally aimed
at the selection of plants with desirable features,
followed by cross-pollination in order to obtain better populations, and then cross-pollinate them
and compare progenies in different environments.
From there, commercial materials with good agronomic and adaptation characteristics are selected.
This process could last from 20 to 25 years, and
it is what has been done so far in oil palm. Scientific advances have created tools to speed up the
traditional breeding process. One of these tools is
the biotechnology, which can be used to identify
desirable genotypes in any of the traditional plant
breeding stages. As complement to this identification, after several years of hard work by different
research groups, an oil palm genotype was finally
obtained and produced commercially. It is commercially known as the "clone", whose production
method is specific for each plant to be cloned.
The great difference between using oil palm
clones and seeds, as it has been done so far, is
that the clone is a single genotype and the commercial seed being used today is a mixture of different genotypes. Therefore, there will be a much
lower effect on the genotype x environment interaction in the seed-propagated material, as the
different genotypes work as buffers, minimizing,
PALMAS - Vol. 26 No.2, 2005
7
in many cases, the effect of soil and weather conditions where the different materials are planted.
However, in the case of clones, this buffer ability
is lost, and the range of adaptation is very limited.
Oil palm cloning should be used only after the
best materials have been identified in a plant
breeding program, in a given environment. Theoretically. these m a s s - p r o p a g a t e d m a t e r i a l s ,
planted in the environment for which they were
created, could get better oil yields per hectare,
under proper agronomic management. This could
pave the way toward precision agriculture and get
closer to the theoretical potential of 18 tons of oil
per hectare.
It is important to take into account that if these
clones, selected under defined agro-climatic conditions. are planted in conditions different from
those in which they were selected, the probability of success is remote.
Then we could ask: When is it safe to use
clones? It is safe when there is a long term, sustainable and organized breeding program behind
its production. It is safe when the breeding program has a germplasm bank with a wide genetic
diversity, so as to be able to isolate desirable genotypes, and the selected ortets are subjected to different agro-climatic conditions.
It is safe when progenies are tested in potential palm growing areas, in such a way that each
zone has identified superior plants to be cloned
and propagated to be then planted where the maximum genotype x environment interactions and
maximum genotype expression can be exploited.
All this should be complemented with a cloning
program safe enough so as to avoid the very frequent abnormalities that occur when the wrong
technology is used.
The Oil Palm Research Center (Cenipalma),
within its program for the production of high yield
oil palm varieties, adapted to the country's main
palm growing areas and resistant to the main
8
PALMAS
pests and diseases in each zone, has began, with
the support of Colciencias, the implementation
of a tissue culture laboratory for the production of
oil palm clones.
We need to have a clear understanding that
the primary objective of Cenipalma's plant breeding research program is to provide the Colombian palm growers with the best planting material for each of the agro-climatic conditions, and
to support domestic seed producers and plantations interested in producing their own planting
material.
Cenipalma is in the process of zoning, from the
agro-climatic perspective-, the different palm growing areas in Colombia, in order to establish regional and progenies tests, so that the best performing genotypes can be propagated for commercial use, either sexually or by cloning. Agronomic
practices suitable for both the edafic-climatic conditions and identified genotypes in each zone will
be developed based on the agro-climatic classification.
The evaluation of Dura materials planted in
the different palm growing areas began in 1996.
There already are some promising materials, and
the idea is to focus on the selection of populations
with desirable features, perform and obtain
Tenera crosses, and conduct regional and progenies tests to identify the most outstanding individuals, clone them and use them in new plantings
or renewal of plantations.
Cenipalma hopes to provide the service to those
Colombian seed producers interested in cloning
material for propagation and sale to palm growers.
Cenipalma plans to form alliances in the country and abroad to speed up the production of the
new planting material that will be the base upon
which the Colombian oil palm precision agriculture will stand in the future, which would represent the possibility of maintaining the sector's
competitiveness at world level.