Genetic diversity in yellow dwarf populations of coconut assessed using RAPD markers

Abstract

RAPD markers were used to analyze genetic diversity and genetic relationship among three Yellow Dwarf coconut accessions. DNA from palms of Malayan Yellow Dwarf (MYD), Kulashekaram Yellow Dwarf (KYD) and Andaman Yellow Dwarf (AYD) were amplified with 16 highly polymorphic RAPD primers. Mean heterozygosity was higher in KYD (0.157) and MYD (0.153) and less in AYD (0.039). Similarity matrix based on Jaccards coefficient indicated a close association of the two indigenous yellow dwarfs (AYD and KYD) with the exotic Yellow Dwarf (MYD). Cluster analysis produced a dendrogram of two major clusters. One palm (KYD16) formed a distinct single accession cluster while rest of the palms grouped into the second cluster which had 10 sub-clusters. The AYD palms formed a distinct sub-cluster within the second group indicating its distinctness and homogeneity. The MYD and KYD palms were scattered in different sub-clusters indicating presence of diversity within the accessions. The 3-D principal coordinate analysis also indicated a distinct grouping of the AYD palms but not the MYD and KYD palms. AMOVA indicated presence of greater diversity within the accessions than between the accessions. Therefore, it is likely that AYD and KYD evolved from a common progenitor, the MYD