Genetic Diversity of Coconut (Cocos nucifera L.) in Sri Lanka Revealed by Randomly Amplified Polymorphic DNA (RAPD) Markers

Abstract

Genetic diversity of seventeen germplasm accessions and three improved cultivars was detenn ined by RAPO analysis. Twenty Operon primers selected from 100 primers were used and these primers amplified coconut DNA generating 129 amplification products averaging 6.5 bands per primer. Among them 84 (65.12%) exhibited polymorphoisms averaging 4.2 polymorphic bands per primer. The Nei and Li pair-wise genetic distance matrix revealed genetic base in the coconut in Sri Lanka with distances ranging from 0.036 - 0.252 with an average distance of 0.145. The 20 coconut types assayed clustered into two groups. The first included all dwarf forms. aurantiaca form King coconut. and San Ramon. The other comprised typica forms and the three improved cultivars .San Ramon grouped with dwarf types exhibiting its evolutionary link with dwarfs as Philippine coconuts. King coconut too indicated a South East Asian Origin similar to dwarfs. As expected improved cultivars grouped with tall types as all these cultivars have a tall as one parent.