利用微卫星标记进行马氏珠母贝家系遗传结构分析与系谱认证

为改良马氏珠母贝养殖群体性状,2010年4月,从马氏珠母贝选育系F3选择性腺成熟个体为亲本,建立了36个家系,按照常规技术进行幼体培育和海区养成.2010年11月,从36个家系中随机选取4个家系,每个家系取样30个个体,利用13对微卫星引物进行家系遗传结构和系谱鉴别分析.结果显示,(1) 13个微卫星引物在4个家系中共检测到39个等位基因,每个位点的等位基因数为2～5,4个家系的平均观测杂合度(Ho)为0.531 ～0.597,平均期望杂合度(He)为0.474 ～0.507；(2)根据子代基因型成功地推断出4个家系的亲本基因型,据此鉴别各个家系；用UPGMA法对120个样本进行聚类分析,98.3％的同一家系的子代个体能够聚到一起,分类结果与系谱来源基本一致.结果说明,这4个家系具有较高的遗传多样性和家系间具有明显的遗传分化；微卫星标记能有效地为马氏珠母贝群体的系谱分析提供技术支持.

Genetic structure and genealogical identification of four families of pearl oyster Pinctada martensii, as inferred by microsatellite markers

In April 2010,thirty-six families were established by selecting mature breeders in the third generation selected line.In November 2011,four families were randomly sampled from the thirty-six families and subjected to the experiment where genetic diversity and kinship of the sampled families were analyzed using thirteen microsatellite markers.Thirty-nine alleles were detected at thirteen microsatellite loci in the four families and the number of the alleles at each locus ranged from two to five.The average observed and expected heterozygosity of the four families varied from 0.531 to 0.597 and from 0.474 to 0.507,respectively.The genetic differentiation index(F_ST)among the four families was 0.15.Based on the genotypes of offspring,all parental genotypes of the four families were successfully deduced. A dendrogram was constructed using UPGMA based on genetic similarity matrix.The UPGAM dendrogram of the 120 individuals indicated that 98.3% of the individuals from each family could be fully clustered and the classification results were consistent with the source of genealogy.Results show that there exists high genetic diversity among the four families and microsatellite marker is a useful tool for genealogical identification of pearl oyster.