长江下游放流鲢群体遗传多样性的微卫星标记分析

利用12个微卫星分子标记对长江下游4个放流鲢群体进行了遗传多样性分析。在12个基因座位中,共检测到56个等位基因,每个座位检测到的等位基因数为1～7个,其中有10个基因座位具有多态性,多态位点百分率为83.33%,4个群体的平均等位基因数A为3.98,平均有效等位基因数Ne为2.384 0,观测杂合度Ho平均值为0.467 6,期望杂合度He平均为0.490 6,多态信息含量平均值为0.381 2。4个鲢群体的遗传多样性较丰富,与文献报道的下游野生群体大致相当,但明显低于上游野生群体;放流鲢群体的平均观测杂合度均低于各自相对应的平均期望杂合度,表现出一定程度的近交现象。4个放流鲢群体间遗传相似系数为0.937 1～0.971 8,遗传距离为0.028 2～0.062 8,基因分化系数Fst为0.027 5～0.050 6,表明群体间的遗传分化程度较弱。

Analysis of Genetic Diversity among Silver the Artificially Released Populations of Carps in the Lower Reach of Yangtze River with Microsatellite Markers

Twelve microsatellite markers were used to analyze the genetic diversity of four artificially released populations of sliver carps in the lower reach of Yangtze River.A total of 56 different alleles were found and the number of alleles in each locus ranged from 1 to 7.Ten loci(83.33%)were polymorphic.In the four populations,the values of average alleles and valid alleles were 3.98 and 2.384 0.The values of average observed and expected heterozygosity were 0.467 6 and 0.490 6 respectively,while the mean PIC was 0.382 1.The genetic diversity of the four artificially released populations was about the same as the lower reach wild populations reported in past articles and significantly lower than that of the upper reach wild populations.The mean observed heterozygosity was lower than the corresponding mean expected heterozygosity,which showed inbreeding happened in some extent in the four silver carp artificially released populations.The genetic similarity coefficient of the four populations was 0.937 1 to 0.971 8,and the genetic distance was 0.028 2 to 0.062 8.Fst value ranged from 0.027 5 to 0.050 6,which indicated that the four populations were faintly differentiated.