Genetic and morphological variation in three populations of Donax spp. in the gulf of Thailand

Abstract

The aim of this research was to evaluate the genetic and morphological variation among the three populations of Donax spp . along the Gulf of Thailand. Samples were collected from Bangsean, Cha-Am and Suansonsandy beaches, and analyzed to reveal genetic and morphological variation by using 4 loci based on Inter-Simple Sequence Repeats markers and 5 morphological variables, respectively. The discriminant function analysis of morphology presented a clear separation among three populations. Polymorphisms were detected at 4 loci across all three populations. The mean number of alleles ranged from 1.65±0.48 to 1.90±0.30 and the effective number of alleles ranged from 1.18±0.27 to 1.29±0.30. Donax spp . from Suanson beach showed the lowest level of genetic variation which Nei’s (1973) gene diversity was 0.16±0.17. While Nei’s (1973) gene diversity of Donax spp . from Bangsean and Cha-Am beaches were 0.18±0.15 and 0.19±0.16, respectively. Percentage of polymorphic loci ranged from 66.22 to 89.86%. Overall results from this research based on genetic variation were in the range of most other marine bivalves, which allows for potential adaptation to environmental changes. Furthermore, the results can be indicated that population of Donax spp . from Suanson beach should be treated as separated units for conservation management.