Genetic Diversrty Analyses Of Pinctada Fucata ( Dunker) In South China Sea Using AFLP And SSR

To understand genetic structure and genetic diversity of Pinctada fucata ( Dunker) in South China Sea region, and to provide scientific instructions for improved strains cultivation, this thesis analyzes genetic diversity of Pinctada fucata (Dunker) (Specimens of DY,H and M of cultured Pinctada fucata are collected Daya Bay, Hepu and Maichen ; Specimens of DZ,BZ,SZ of wild populations were collected in Daya Bay Beibu Bay and Sanya Bayin southern China ).1.Ten pairs of AFLP selective amplification primers totally amplified 364 loci of different size. The proportion of polymorphic loci DY,DZ,H,M,SZ,BZ groups are 86.21%,64.67%,82.12%,83.02%,64.73%,63.30%;Average distance between clusters of DY,DZ,H,M,SZ,BZ groups is 0.2967,0.2519,0.2478,0.2047,0.1913,0.1856;genetic distance and cluster analysis of six groups reveals that wild groups and cultured groups have certain gene exchange. Range of genetic distance's variation among six groups is from 0.2327 to 0.4278, Range of variation of genetic distance of H,DY,M three cultured groups is from 0.3001 to 0.3017. Range of genetic distance's variation of three wild groups DZ,BZ,SZ is from 0.3017 to 0.3801.The genetic distance between H cultivated group and DZ is largest , the genetic distance between H group and SZ group comes second, the genetic distance between M group and DY group is smallest, six groups still keep high genetic diversity. The research results indicate that the genetic distance among cultivated groups is larger, genetic distance among populations is larger than that within populations. So hybridization among different populations is a way to restore genetic diversity of cultivated and wild populations.2. Ten pairs of SSR amplification primers were used analyzing Pinctada fucata: Average distance between clusters of DY,DZ,H,M,SZ,BZ groups is 0.1985,0.1969,0.1852,0.1726,0.1543,0.1321; Range of genetic distance's variation among six groups is from 0.3009 to 0.4704, Range of variation of genetic distance of H,DY,M three cultured groups is from 0.3009 to 0.4148. Range of genetic distance's variation of three wild groups DZ,BZ,SZ is from 0.3214 to 0.4148.The genetic distance between H cultivated group and DZ is largest , the genetic distance between H group and SZ group comes second, the genetic distance between M group and DY group is smallest, six groups still keep high genetic diversity. The research results indicate that the genetic distance among cultivated groups is larger, genetic distance among populations is larger than that within populations.3.Emergences of various populations have specific sites deficiency, so combining multiple specific sites may effectively identify different geographical groups and restore germplasm resources. The results show that groups remained relatively high heterozygosity, germplasm resources in relatively good condition.