长江中下游湖泊和云南抚仙湖黄颡鱼群体遗传结构研究

Population genetic structure of Pelteobagrus fulvidraco in the lakes of the middle and lower reaches of the Yangtze River and in Fuxian Lake of Yunnan

采用10个微卫星位点对长江中下游5个湖泊和云南抚仙湖黄颡鱼群体遗传结构进行分析.结果显示,黄颡鱼各群体平均等位基因数为3.5~4.6,平均有效等位基因数为2.240~3.041,平均观测杂合度为0.343~0.499,平均期望杂合度为0.432~0.600,平均多态性信息指数为0.389~0.571.鄱阳湖、滆湖和洪泽湖群体的遗传多样性高于太湖、巢湖和抚仙湖群体.群体间的遗传距离为0.089~0.524,其中,鄱阳湖与巢湖群体的遗传距离最小,鄱阳湖与滆湖群体遗传距离最大,IBD分析结果显示黄颡鱼群体不遵循地理距离模型.AMOVA显示大多数遗传变异存在于群体内（84.51%）,群体间的遗传变异为15.49%（Fst=0.1549）,表明黄颡鱼群体存在明显的遗传分化,两两遗传分化指数也证实了这一点.UPGMA聚类和Structure分析结果均显示6个黄颡鱼群体可分为2组,鄱阳湖、巢湖和洪泽湖为一组,滆湖、太湖和抚仙湖群体为另一组.

Ten microsatellite loci were used to analyze the population genetic structure of Pelteobagrus fulvidraco in five lakes of the middle and lower reaches of the Yangtze River and in Fuxian Lake of Yunnan.In P.fulvidraco populations,the average number of alleles was 3.5to 4.6with the mean number of valid alleles being 2.240 to 3.041.The average value of observed and expected heterozygosity ranged from 0.343 to 0.499and0.432 to 0.600,and the mean PIC was 0.389 to 0.571.Genetic diversity parameters indicated that the populations from Poyan Lake,Ge Lake,and Hongze Lake had higher levels of genetic diversity than those from Taihu Lake,Chao Lake and Fuxian Lake.The value of pairwise genetic distance was 0.0089 to 0.524.The genetic distance between Poyang Lake and Chao Lake was the smallest,while the largest one was that between Poyang Lake and Ge Lake.IBD results showed that P.fulvidraco populations did not match the geographic distance model.AMOVA analysis revealed that most of the total variation occurred within populations（84.51%）.The amount of differentiation among populations was 15.49%（Fst=0.1549）,which exhibited a clear population differentiation.Pairwise Fst comparisons of populations also confirmed this. Both UPGMA clustering and Structure analysis results showed that the six populations were able to be divided into two groups.One was assembled with the individuals from Hongze Lake,Poyang Lake and Chao Lake,while the other was consisted of the individuals from the rest lakes.