Genetic Diversity Analysis of Coconut (Cocos nucifera L.) Genotypes and Hybrids Using Molecular Marker

Abstract

The present investigation was carried out to study molecular diversity of different coconut genotypes and hybrids using PCR based molecular markers to find out the phylogenic relationship among them. In this study, 15 RAPD, 15 ISSR and 15 SSR primers were used to observe the relationship and polymorphism of coconut genotypes. Total 15 RAPD primers used for the study has generated 82 polymorphic bands having 80 shared and 2 unique bands with an average of 5.46 bands with 100% polymorphism per primer. The 15 ISSR primers engendered 82 bands in which 80 bands were polymorphic with 75 shared and 5 unique bands that were equal to 100% polymorphism with an average of 5.3 bands per primer. Total 15 SSR primers generated the 28 fragments in which 23 bands were polymorphic having 22 shared and 1 unique band with 75.55% polymorphism with an average of 1.5 bands per primer. The similarity coefficient of clusters analysis ranged from 22 to 83% for RAPD, 26 to 86% for ISSR and 50 to 97% for SSR. Dendrogram construction of all these the molecular markers showed that in RAPD, Nikobar variety of coconut was the most diversified variety observed having alone separate position. The pooled study of RAPD, ISSR and SSR generated clustering pattern appeared to be similar as RAPD clustering pattern. Based on the molecular markers associated with coconut genotypes, it was concluded that all molecular markers like RAPD, ISSR and SSR are most reliable to distinguish coconut genotypes. RAPD primers OPC-05 and OPF-05, ISSR primers UBC-818, UBC-825, UBC-843, UBC-847 and UBC-848, SSR primer WCYZ3554 gave variety specific markers in all coconut varieties.