长江下游鳙放流群体和天然捕捞群体遗传多样性的微卫星分析

摘要

利用18对微卫星分子标记对长江下游鳙3个放流群体和1个天然捕捞群体进行遗传多样性分析.在18个基因座中,共检测到109个等位基因,每个座位检测到的等位基因数为3～10个,18个基因座位都具有多态性,多态位点百分率为100％,鳙4个群体的平均等位基因数A为5.055 ～5.666,平均有效等位基因数Ne为3.482～3.948,观测杂合度Ho平均值为0.678 ～ 0.753,期望杂合度He平均值为0.672 ～0.721,多态信息含量平均值为0.604～0.633,4个群体的遗传多样性较丰富.4个群体间遗传相似系数为0.883 ～0.936,遗传距离为0.066～0.133,基因分化系数Fst为0.023 ～0.051,表明群体间的遗传分化程度较弱,人工放流群体的遗传多样性和长江常熟江段天然捕捞群体的遗传多样性没有显著差异,放流群体的种质资源状况良好.建议加强增殖放流苗种的种质资源控制.%Eighteen microsatellite markers were used to analyze the genetic diversity of bighead carp of four populations,including three released populations and one population caught in natural water in the lower reach of the Yangtze River.A total of 109 different alleles were found and the number of alleles in each locus ranged from 3 to 10.Eighteen loci (100％)were polymorphic.In the four populations,the values of average alleles and valid alleles were 5.055-5.666 and 3.482-3.948.The values of average observed and expected heterozygosity were 0.678-0.753 and 0.672-0.721 respectively,while the mean PIC was 0.604-0.633,which revealed rich genetic diversity in the four populations.The genetic similarity coefficient of the four populations was 0.883 to 0.936 and the genetic distance was 0.066 to 0.133,while Fst value ranged from 0.023 to 0.051,which indicated that the four populations were faintly differentiated and there was no significant difference in genetic diversity between the released populations and the natural population caught in Changshu section of the Yangtze River.Germplasm resource of released populations was in good situation.More attention must be paid to germplasm control of the released fry.