Diana Arias

Molecular characterization of oil palm Elaeis guineensis Jacq. materials from Cameroon

The narrow genetic base of existing commercial oil palm cultivars has prompted oil palm breeders to give increased importance to augmenting these genetic resources because the sustainable development of the crop depends largely on the availability of genetic diversity and its use. Therefore, the purpose of this study was to conduct a molecular characterization of an ex situ collection of oil palm Elaeis guineensis Jacq. populations from the Republic of Cameroon using microsatellite molecular markers. Overall, 31 simple sequence repeats were polymorphic, with a total of 223 alleles, 78.4% of which were found at low frequency. The total genetic diversity was relatively high (HT ¼ 0.673). The genetic differentiation between geographical regions was low (GST ¼ 0.023, P ¼ 0.001), and between families it was high (GST ¼ 0.166, P ¼ 0.001), showing greater variation between families than among geographical regions. The molecular data indicate that genetic diversity among the genotypes evaluated is mainly distributed within regions, suggesting that there is no isolation by geographical distance and that all the sampled individuals form a single diverse population. Therefore, it was concluded that a relatively low number of accessions (120 in the analysed case) that includes at least one representative of each family would allow us to efficiently collect almost the entire genetic diversity of Cameroon within the collection studied. This will allow for the efficient use of genetic resources and a reduction in morpho-agronomic characterization costs.

Morpho-agronomic and molecular characterisation of oil palm Elaeis guineensis Jacq. material from Angola

The characterisation of phytogenetic resources is used to improve conservation strategies, promote new sources of plant material, and design breeding strategies. In this study, we evaluated oil palm material with nine morpho-agronomic traits and 30 microsatellite markers (Simple Sequence Repeats; SSRs) that had been previously collected in five geographical regions of Angola. The analysis of variance for components of bunch production and oil yield showed highly significant (p < 0.001) statistical differences between geographical regions and among families for all traits evaluated. The SSRs were highly informative, suggesting high genetic diversity (HT = 0.666) among the accessions evaluated. However, the clustering pattern at both morpho-agronomic and molecular levels did not match the geographical distribution of accessions, showing a low genetic differentiation (GST = 0.039) between regions. On the other hand, genotypic (GST = 0.150) and phenotypic differences were found among families, which could offer the potential for future genetic gains in the oil palm. The information generated indicates that the evaluated accessions have desirable characteristics that should be included in breeding programs, which could expand the genetic basis of the crop.

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

Elaeis oleifera has become a valuable genetic resource for the production of interspecific hybrids of E. oleifera (H.B.K) Cortés × 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.