Genetic Diversity and Relationships of Three Razor Clam Species (Sinonovacula constricta, Solen strictus and Solen grandis) Revealed by RAPD and ISSR Markers

Random amplified polymorphic DNA (RAPD) and Inter-simple sequence repeats (ISSR) markers were used to study the genetic diversity and relationships in three razor clam species (sinonovacula constricta, solen strictus and solen grandis). 14 random primers for RAPD analyzing generated 113 bands, out of which 105 (92.92%) were polymorphic loci and with an average of 8.1 bands per primer. Nine primers for ISSR analyzing generated 171 bands, out of which 169 (98.83%) were polymorphic loci and with an average of 19 bands per primer. Both Shannon´s gene diversity index and Nei´s gene diversity index within population comprehensively indicated that S. constricta possessed the lowest diversity, intermediate in Solen grandis and the highest in Solen strictus. The genetic distances among the three razor clam species calculated by RAPD and ISSR ranged from 0.4122 to 0.5505, and 0.2987 to 0.3842, respectively. Two UPGMA dendrograms of RAPD and ISSR were performed based on the Nei´s genetic distances. Each dendrogram had two main clusters, one cluster including Solen strictus and Solen grandis, and the other was S. constricta. All of the results obtained in this study indicate that RAPD and ISSR markers are useful for genetic diversity analysis in razor clams.