Production of virescens varieties of Nigeria origin
Oil palm fruit color is one of the criteria used to determine the maturity of the bunches; the change in color is one of the traits that helps distinguish whether a bunch is mature and, consequently, if the oil content in the fruits is at its maximum. However, this criterion is not completely reliable, since the black color (nigrescens) of the bunches changes little when these mature. For this reason, the presence of loose fruits on the ground is the main criterion for deciding when to harvest; even so, workers have difficulty distinguishing maturity and often cut a large number of immature bunches whose oil content is lower.
An alternative to improve the efficiency of the harvest is to develop varieties with virescens fruits. Virescens bunches have fruits that are green when they are immature and these change to a bright reddish-orange color when ripe; a trait that makes them easily distinguishable for harvesting. This trait is governed by a single pair of dominant genes, and there is segregation when one of the parents has the virescens trait. Currently, work is being done to purify those commercial varieties where a proportion of the plants possess this trait (Deli x Nigeria and Compact x Nigeria), so that ASD can offer crosses that produce only virescens bunches in the near future.
It has been determined that there is segregation of the color of the fruit in the descendants of some tenera and pisifera palms of Nigeria origin, within which three tenera and three pisifera palms were identified, where this trait (virescens) is in a homozygous condition. These pure virescens progenies have moderate to high fruit production but lower oil content in the bunch. In general, the descendants with higher production coming from palms whose virescens condition is heterozygous. Currently, we are in the process of searching for molecular markers associated with the virescens gene, and we are going to start a second stage of progeny testing to identify new palms with this trait that are also homozygous and have high oil productivity. In the future the aim is to obtain commercial T/P populations (AVROS, Ekona, Ghana, La Mé, Compact) with the virescens trait as the product of a gene introgression process, to initiate evaluation and purification programs, or to achieve this objective through genetic engineering.
Young Deli x Nigeria palm showing immature green color bunches (virescens) and ripe orange bunches