Genetic Diversity, Erosion, and Conservation in Oil Palm (Elaeis guineensis Jacq.)

Abstract

African oil palm (Elaeis guineensis Jacq.) is a perennial crop that offers a variety of products for food, non-food, and medical uses worldwide. Sustainable oil palm development is expected from the species with high genetic diversity within ex situ and in situ populations. From the Guinea golf in Africa, oil palm adapted to the humid tropics of Africa, Southeast Asia, and Latin America, thanks to this high genetic diversity. Indicators of the species’ genetic variability include (i) multiple fruit shell forms, (ii) diverse fruit exocarp color types, and (iii) wide variation of morphological and agronomic characters. The high genetic variability within oil palm materials has been confirmed by molecular marker techniques. As for many other plants, pests and diseases, breeding, and human activities in natural oil palm groves are responsible for genetic erosion or loss of alleles or genes resulting from the death of oil palms, i.e., decreasing population size. In fact, molecular markers have revealed low genetic diversity in breeding populations which are usually smaller than natural collections. Efforts have been taken to preserving oil palm germplasms and to collecting and conserving new materials from the natural oil palm belt in Africa for improved oil palm profitability and for posterity. Constraints in oil palm conservation are the requirements of large space (at 148 palms per hectare) and regular maintenance incurring high upkeep costs. Furthermore, the long-term in vitro conservation techniques have not yet been established and seeds cannot tolerate storage at a low temperature. Fortunately, locals in the African oil palm belt are concerned with the preservation of the species’ natural groves. They select oil palms to fell for palm wine production, maintain existing palm trees, create suitable conditions for the growth of seedlings, and do not cut seedlings during bush clearing or weeding of farms.