墨西哥湾扇贝与“中科红”海湾扇贝群体遗传多样性SSR分析

SSR Analysis of Genetic Diversity of Argopecten irradians concentricus and Zhongkehong Argopecten irradians

利用微卫星（SSR）分子标记技术,对墨西哥湾扇贝和“中科红”海湾扇贝2个群体共80个个体的遗传结构和遗传多样性进行分析。结果显示：6个微卫星位点共扩增出31个等位基因,各位点的等位基因数为4~8个,平均等位基因数为5.2个;墨西哥湾扇贝与“中科红”海湾扇贝群体平均有效等位基因数（Ne）分别为2.890、2.753;平均观测杂合度（Ho）分别为0.415、0.353;平均期望杂合度（He）分别为0.604、0.479;多态信息含量（PIC）分别为0.554、0.444;两群体具有相同的等位基因数（Na）（4.333）。Hardy-Weinberg平衡检验发现,2个群体各有3个位点（50%）偏离平衡（p〈0.05）,且均表现为杂合子缺失。两群体的遗传分化指数（Fst）为0.109 7,遗传距离（Dxy）为0.316 4,遗传相似性系数为0.728 8。研究结果说明：两个群体均保持较高的遗传多样性,但经过多年的定向选育,“中科红”海湾扇贝群体的遗传多样性低于墨西哥湾扇贝群体且两个群体具有中等程度的遗传分化,存在一定的遗传差异。

The genetic structure and diversity of 80 individuals in the 2 populations of Argopecten irradians concentricus and Zhongkehong Argopecten irradians were analyzed by microsatellite（SSR） molecular marker technique.The results showed that a total of 31 alleles were amplified by 6 microsatellite loci and the number of allelesranged from 4 to 8, of which the average was 5.2; the average effective number of alleles（Ne） of the Argopecten irradians concentricus and Zhongkehong Argopecten irradians populations were 2.890 and 2.753, respectively; the average observed heterozygosity（Ho） were 0.415 and 0.353, respectively; the average expected heterozygosity（He） were 0.604 and 0.479, respectively; the polymorphism information content（PIC） were 0.554 and 0.444, respectively; the same number of alleles（Na） was found in the two populations（4.333）. The Hardy-Weinberg balance test showed that 3 loci（50%） in each population were out of balance（p〈0.05）, and all of them showed heterozygote deletion. The genetic differentiation index（Fst） was 0.109 7, genetic distance（Dxy） was 0.316 4, and genetic similarity coefficient was0.728 8 in two populations. The results of this study indicated that the two populations had higher genetic diversity,but after years of artificial breeding, the genetic diversity of Zhongkehong Argopecten irradians population was lower than that of Argopecten irradians concentricus population. Moreover, two populations had moderate genetic differentiation, and there were genetic differences between them.