14个克氏原螯虾养殖群体遗传多样性分析

Genetic Diversity Analysis of 14 Cultured Populations of Red Swamp Crayfish Procambarus clarkii in China

克氏原螯虾种苗自繁自育使其种质严重退化。遗传多样性是反映种质退化与否的重要指标之一。为评估我国克氏原螯虾养殖群体的遗传多样性,采集我国江西、浙江、广东和湖北省14个地域的464尾克氏原螯虾养殖群体,利用35个微卫星分子标记分别对其等位基因数、期望杂合度、观测杂合度、多态性信息含量、哈迪-温伯格平衡、遗传距离及群体结构等进行分析。结果显示:14个养殖群体的不同标记位点的等位基因数为2~3个;多态信息含量、平均观测杂合度与期望杂合度分别为0.33~0.43、0.32~0.41与0.36~0.44;各标记位点均存在杂合子缺失而未达到哈迪-温伯格平衡;14个群体可聚类为4个遗传群体,其中香树坝、温州、衢州群体与吉安、天荒坪、递铺群体分别聚为2个遗传群体,龙南群体及其余的群体属于另外2个遗传群体。以上结果表明,我国克氏原螯虾养殖群体仅具有中等遗传多样性,收集和保护遗传多样性较高的克氏原螯虾野生种质资源对其遗传育种具有重要意义。

To assess the genetic diversity of cultured populations of red swamp crayfish Procambarus clarkii,14 populations,464 samples,of red swamp crayfish,were collected from Jiangxi,Zhejiang,Guangdong and Hubei provinces in China.The number of alleles,expected heterozygosity(H_(e)),observed heterozygosity(H_(o)),polymorphism information content(PIC),Hardy-Weinberg equilibrium,genetic distance and population structure of red swamp crayfish were analyzed by the 35 simple sequence repeat(SSR)markers.The results showed that there were 2-3 alleles for each SSR marker site;the values of PIC,H o and H e were arranged from 0.33 to 0.43,0.32 to 0.41,and 0.36 to 0.44,respectively.Absent heterozygote in each marker locus resulted in the loss of Hardy-Weinberg equilibrium.Four genetic populations can be grouped according to the genetic distance and population structure of the 14 populations,and the populations from Xiangshuba,Wenzhou,Quzhou,and Jian,Tianhuangping,Dipuwere classified into the two independent clades,respectively.The population from Longnan and the other populations were clustered into another two clades,respectively.The findings indicate that the cultured populations of red swamp crayfish in this study only show a medium genetic diversity,hence,the collection and protection of the wild crayfish germplasm with a higher genetic diversity will play an important role in the genetic breeding.