Genetic variation in Chinese hatchery populations of the Japanese scallop ( Patinopecten yessoensis) inferred from microsatellite data

Abstract

The Japanese scallop Patinopecten yessoensis was introduced to China about two decades ago from Japan. In aquaculture, there are concerns as to whether genetic variability would have been lost in farmed populations during their subsequent hatchery production. Using six microsatellite loci, three hatchery populations of P. yessoensis in China were compared with one another and with two wild Japanese populations. The hatchery populations were substantially less variable than wild populations. For the hatchery and wild populations, the average numbers of alleles per locus were 5.7 and 7.9, and the average expected heterozygosities were 0.582 and 0.671, respectively. This loss of variation is attributable to about 20 years of isolation and genetic drift. F st values showed significant genetic differentiation among the five populations. Genetic differences between the populations were also detected by pairwise comparison based on allelic distribution. The Neighbor-joining tree topology constructed on the basis of genetic distances among populations showed a clear division between the wild and hatchery populations. The information on the genetic variation and differentiation in cultured and wild populations of P. yessoensis obtained in this study is useful for setting up suitable guidelines for founding and maintaining of cultured stocks, and for future genetic improvement by selective breeding.