Genetic and phenotypic diversity of natural American oil palm (Elaeis oleifera (H.B.K.) Cortés) accessions

Abstract

Elaeis oleifera has become a valuable genetic resource for the production of interspecific hybrids of E. oleifera (H.B.K) Cortes × Elaeis guineensis Jacq. to address plant disease problems affecting oil palm cultivation. In this study, we evaluated the phenotypic and genetic diversity of accessions of E. oleifera from different countries in South America using morpho-agronomic traits and microsatellite markers (Simple Sequence Repeats, SSRs). Analyses of variance for yield and bunch components demonstrated statistically significant differences among countries and geographical regions for several of the traits evaluated. SSR marker analyses revealed high genetic diversity (HT = 0.797) and the presence of specific alleles by each country of origin from E. oleifera. The clustering topology obtained showed four distinguishable E. oleifera groups, which matched the geographical distribution of the accessions and thus exhibited a high genetic differentiation (GST = 0.512) and a low gene flow Nm = 0.238 among countries. The results enabled us to demonstrate that E. oleifera has a specific genetic structure and a phenotypic variability with different characteristics between origins, and the accessions from each country of origin contributed to the increase in total genetic diversity. A core collection was defined based on the accuracy of the classification of individuals with respect to their country of origin. The information reported in this study will be of great interest to oil palm researchers because new strategies for breeding programs can be developed based on these advances.