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

Abstract

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.