Improved SSRs-Based Genetic Diversity Assessment of Coconuts (Cocos Nucifera L.) Along the Coast of Kenya

Abstract

Coconut is the most important cash crop along the Coast of Kenya, yet its genetic diversity has not been fully established. A genetic diversity study of 48 coconut genotypes that were collected along the Coast of Kenya was conducted with 13 polymorphic short sequence repeats (SSRs) markers. SSR analysis was performed using GeneMapper while data analysis was done with PowerMarker and DARwin softwares. The results revealed a total of 68 alleles ranging from 2 to 11 per locus with a mean of 5.23 per marker. Gene diversity and polymorphic information content (PIC) ranged between 0.41 to 0.83 and 0.33 to 0.79, respectively. A neighbour-joining dendrogram grouped the genotypes into three major clusters containing distinct sub clusters. This study underscored that capillary electrophoresis is a more accurate and informative technique for SSRs allele scoring than agarose gels, which was reported in a previous study with the same SSRs markers and coconut genotypes in Kenya. The clusters observed forms the basis to isolate conservation blocks, which are the key to establishing a genebank, since there is no documented coconut genebank for ex-situ conservation in Kenya.