Analysis of genetic diversity among Indian Ocean coconut accessions through microsatellite markers

Abstract

The extent of genetic diversity among nineteen coconut accessions comprising collections from the Indian Ocean Islands were characterized with eight polymorphic microsatellite primers. The fixation index (Fst) was found to be higher (0.78) between Laccadive Micro (LMT) and Chowghat Orange Dwarf (COD) population and the lowest Fst value (0.04) was found among the population Guelle Rose Tall (GLT) and Sri Lankan Tall (SLT). An average Fst value of 0.48 was observed for the accessions indicating higher level of population differentiation among the accessions. The maximum genetic distance (2.29) was observed between Laccadive Green Tall (LGT) and Chowghat Orange Dwarf (COD). The minimum genetic distance (0.04) observed between Laccadive Micro (LMT) and Srilankan Tall (SLT). Overall, the within population variation was found to be higher (67%) than among the population variation (33%) for these coconut accessions. The clustering pattern distinguished two main groups among the Indian Ocean Islands population. The control population COD formed the first group and the remaining populations form the second group. The clustering within the second group revealed the relationship among the accessions under study and the information on possible migration of coconut types within the region which could be useful for planning future collections as well the utilization of conserved types.