SSR and ISSR Markers based Population Genetic Structure of Coconut (Cocos nucifera L.) Germplasm Accessions

摘要

The coconut palm (Cocos nucifera L.) is one of the major perennial oil crops of tropics. Population genetic structure was assessed among 33 accessions (4 individuals per accession) with ISSR and SSR markers. The molecular marker data were analyzed with POPGENE and ARLEQUIN software. The parameters derived were, Shannon's index, differentiation indices (Fst and Gst) and molecular variances. The diversity was partitioned into 'within population' (59.82% and 68.56% based on ISSR and SSR markers, respectively) and 'between populations' (40.18% and 31.44% based on ISSR and SSR markers, respectively). Relatively high 'between populations' diversity was present in the accessions belonging to South Pacific region reflecting higher population differentiation. Dwarfs and intermediate coconut types also maintained high 'between populations' diversity due its autogamous behaviour. There was overall reduction in the number of markers (ISSR and SSR) among the dwarfs and intermediate populations. The study provided useful information regarding the genetic makeup of the coconut germplasm accessions and their utilization in breeding.