洞庭湖水系五强溪水库光泽黄颡鱼(Pelteobagrus nitidus)遗传多样性的AFLP分析

ANALYSIS OF GENETIC DIVERSITY OF PELTEOBAGRUS NITIDUS IN WUQIANGXI RESERVOIR OF DONGTING LAKE WATER SYSTEM BY AFLP MARKERS

为了了解沅水五强溪大坝阻隔对光泽黄颡鱼可能造成的遗传多样性影响,采用AFLP分子标记技术,对沅水五强溪水库库区和沅水下游两个光泽黄颡鱼野生群体进行了遗传多样性分析。9对选择性引物在两个光泽黄颡鱼群体中,共扩增出1243个位点,多态位点1091个,多态位点比率为87.77%。其中库区和沅水下游群体多态位点比率分别为85.41%、83.25%,观测等位基因数分别为1.854±0.592、1.803±0.622,有效等位基因数分别为1.597±0.381、1.574±0.377,Nei’s多样性指数分别为0.220±0.211、0.207±0.195,Shannon’s信息指数分别为0.330±0.305、0.302±0.338;两个群体内的平均遗传距离分别为0.124±0.072、0.119±0.057,群体间的平均遗传距离为0.127±0.100。两个群体的遗传参数比较不存在显著差异(P>0.05)。聚类分析显示,UPGMA系统树没有依据群体而形成明显的两大分支。以上结果表明,五强溪水库库区和沅水下游两个光泽黄颡鱼群体的遗传多样性丰富,光泽黄颡鱼种群遗传结构对水库大坝阻隔的响应不明显。

To understand the genetic effects of hydropower development of Wuqiangxi in Yuanshui river of Dongting lake water system, which may have on Pelteobagrus nitidus populations, we analyzed genetic diversities of two populations of Pelteobagrus nitidus in reservoir area of Wuqiangxi reservoir and the downstream of Yuanshui river using AFLP markers. 9 selective primer pairs were used to analyze the two Pelteobagrus nitidus populations. A total of 1243 loci were detected. Of the 1243 detected loci, 1091 loci displayed polymorphism, the percentages of polymorphic loci were 87.77%. Of the two populations in reservoir area and downstream of Yuanshui river, the percentages of polymorphic loci were 85.41%, 83.25%, respectively, the observed number of alleles were 1.8544-0.592, 1.803：t：0.622, respectively, the effective number of alleles were 1.5974-0.381, 1.574＋0.377, respectively, the Nei＇s diversity index were 0.220＋0.211, 0.207~0.195, respectively, and the Shannon＇s information index were 0.3304.0.305, 0.3024-0.338, respectively; The average genetic distances within populations were 0.1244.0.072 and 0.1194.0.057, respectively, and which was 0.1274.0.100 between populations. There was no significant divergence with the genetic parameters between populations （P〉0.05）. Unweighted pair-group methods with arithmetic means （UPGMA） cluster analysis showed that the dendrogram did not form two big branches according to the two populations. The results indicated that there were abundant genetic diversities within populations and the genetic structure variation ofPelteobagrus nitidus populations were not obvious in response to the dam block of Wuqiangxi reservoir.