Genetic Diversity Of Four Hyriopsis Cumingii (Bivalvia: Unionidae) Populatons By SSR Analysis

Hyriopsis cumingii is the major freshwater pearl mussel, spread widely in the eastern, southern and center of China. The reseach of Hyriopsis cumingii constitutes of morphology, ecology, biochemistry, cell biology and so on. As the result of pearl production increased, the cultured scales of Hyriopsis cumingii expanded. With the large quantity catching and high-density culturing, the genetic diversity of Hyriopsis cumingii was destroyed in different extent, the resources deduce year by year. Working about the genetic diversity of Hyriopsis cumingii will benefit protecting the resources of Hyriopsis cumingii, and provide the scientific evidence for breeding and output in great large scale.Genetic diversity of four Hyriopsis cumingii groups was evaluated on the basis of eight microsatellite markers with polymorphism, selected from twenty microsatellite markers which belong to Epioblasma capsaeformis and Margaritifera margaritifera. The samples of four geographic populations of Hyriopsis cumingii were collected from Dongting Lake (DY), Poyang Lake (PY), Tai Lake (TY) and Hunan cultured population (HY). The PCR amplified products of microsatellites were detected by polyacrylamide gel electrophoresis (PAGE). Allele frequency, effective numbers of alleles (n_e), polymorphism information content (PIC), gene heterozygosity (H), and genetic distances (D_s) between these groups were estimated. And then, cluster analysis based on those calculated genetic distances was performed for the four Hyriopsis cumingii populations.The results showed that every microsatellite locus analyzed were polymorphic in those Hyriopsis cumingii populations with an average number of alleles per locus and the polymorphism information content (PIC) equal to 5 and 0.5824 respectively. The results suggested that microsatellite markers can be used to evaluated genetic diversity of Hyriopsis cumingii. Rates of hetrozygosity in four groups are all high, and that is the highest in TY (0.7500), the second is DY (0.7083), the third is PY (0.6500), and the last is HY (0.6500), which suggested that those Hyriopsis cumingii groups had abundant genetic diversity and potential of selection. The result of genetic distance indicated that there were close genetic relationship among those Hyriopsis cumingii groups. The results of cluster analysis suggest that the relationship between DY and HY is the nearest.