利用微卫星分子标记分析长江、赣江和鄱阳湖鲢群体遗传结构

Population genetic structure of silver carp from Yangtze River,Ganjiang River and Poyang Lake based on microsatellite markers

利用10个高度多态的微卫星标记对采自长江、赣江、鄱阳湖湖口和都昌水域的4个鲢野生群体遗传结构进行分析。检测到148个等位基因,每个微卫星位点的等位基因数5-24,有效等位基因数6.4-7.1,平均观测杂合度Ho为0.802-0.821,平均期望杂合度He为0.817-0.839,表明这4个鲢群体遗传多样性较高。鲢群体间的遗传相似系数为0.922 2-0.944 1,遗传距离为0.057 6-0.081 0,固定系数Fst值为-0.012 35-0.005 28,表明这4个鲢群体间遗传一致性高,遗传距离小,群体遗传分化不显著。AMOVA结果显示遗传变异主要来自群体内,基因流分析认为长江、赣江、鄱阳湖鲢群体存在频繁的基因交流。

Ten microsatellite markers were employed to analyze the genetic structure of four silver carp （Hypophthalmichthys molitrix） populations from Yangtze River,Ganjiang River and Poyang Lake and a total of 148 alleles were detected.The number of alleles per locus ranged from 5 to 24,the effective alleles ranged from 6.4 to 7.1 ,the average observed heterozygosity ranged from 0.802 to 0.821 , and the average expected heterozygosity ranged from 0.817 to 0.839 , indicating a high level of genetic diversity in the four silver carp populations.The genetic similarity coefficient ranged from 0.922 2 to 0.944 1 ,the genetic distance of these populations ranged from 0.057 6 to 0.081 0,the fixation index Fst values ranged from-0.012 35 to 0.005 28, which revealed that genetic consistency in the four silver carp populations was high,the genetic distance was small and the genetic differentiation was not significant.AMOVA analysis showed that genetic variation mainly came from within populations, and gene flow analysis indicated that genetic exchange of silver carp in Yangtze River, Ganjiang River and Poyang Lake was frequent. Our study provided valuable information on the germplasm resources of silver carp in Yangtze River,Ganjiang River and Poyang Lake, which could help develop appropriate policies on the conserva-tion and utilization of silver carp.