马氏珠母贝(Pinctada martensii)黑壳色养殖群体SSR遗传多样性分析

Analysis of Genetic Diversity in Black Shell Color Populations of Pinctada martensii by SSR Markers

本研究利用微卫星分子标记技术,对马氏珠母贝(Pinctada martensii)F8代黑壳色普通养殖群体和黑壳色选育群体2个群体共78个个体的遗传多样性进行分析。结果显示,10个SSR位点共扩增出34个等位基因,各位点的等位基因数为2~6个,平均等位基因数为3.4个,黑壳色普通养殖群体和黑壳色选育群体等位基因数(Na)分别为3.3和3.2,有效等位基因数(Ne)分别为1.9935和1.9310;香农多样性指数(I)为0.8013和0.7464;观测杂合度(Ho)分别为0.3300和0.2867;期望杂合度(He)分别为0.4698和0.4343;多态信息含量(PIC)分别为0.403和0.377。Hardy-Weinberg平衡检验发现,2个群体分别有6个、7个位点偏离平衡(P<0.05),其中在4个相同位点中偏离平衡,且均表现为杂合子缺失(Ho<He)。两群体的遗传分化指数(Fst)、近交系数(Fis)、基因流(Nm)分别为0.0372和0.3090和6.4717。研究结果显示:经过连续的继代选育,马氏珠母贝黑壳色选育群体仍然保持适中的遗传多样性,具备作为选育材料的潜力。

This study is about the genetic diversity analysis of 78 individuals in the Pinctada martensii F8 of the black shell color common cultured population and black shell color breeding population by microsatellite molecular marker technology.The results showed that a total of 34 alleles were detected in 10 SSR loci.The number of alleles per locus(Na)was 2~6,and the average number of alleles was 3.4.The allele number respectively was 3.3 in common population and 3.2 in breeding population.The number of effect alleles(Ne)of breeding population and common population was 1.9935 and 1.9310,respectively,the shannon diversity index(I)was 0.8013 and 0.7464,the average observed heterozygosity(Ho)was 0.3300 and 0.2867,the average expected heterozygosity(He)was0.4698 and 0.4343,the polymorphism information content(PIC)was 0.403 and 0.377.Hardy-Weinberg equilibrium test showed that 6 loci and 7 loci deviated from equilibrium in two populations(P<0.05),among which 4 identical loci deviated from equilibrium,and all of them showed heterozygote deletion(Ho<He).The genetic differentia-tion index(Fst),inbreeding coefficient(Fis)and gene flow(Nm)were 0.0372,0.3090 and 6.4717,respectively.The results showed that the black shell color breeding population of P.martensii still maintained moderate genetic diversity and had potential as breeding material after years of artificial breeding.