钱塘江日本沼虾野生群体遗传变异的SSR分析

Microsatellite analysis of genetic variation of the oriental river prawn Macrobrachium nipponense in Qiantang River

利用微卫星标记分析了钱塘江干流水域闻堰、富阳、场口、桐庐等7个野生日本沼虾群体的遗传多样性和遗传结构。结果表明:10个微卫星位点呈现高度多态性;闻堰、富阳、场口、新安江等中下游野生群体的遗传多样性水平有高于歙县和休宁两个上游群体遗传多样性水平的趋势。符号检验和Wilcoxon符号秩次检验的结果表明,钱塘江日本沼虾群体近期没有发生瓶颈效应,群体数量也没有下降。FST的范围介于0.0201～0.1069。分子方差分析结果显示,大部分的遗传变异(93.48%)存在于个体间,少部分遗传变异(6.52%)存在于群体之间。群体间FST及AMOVA分析表明,群体处于中等遗传分化水平;基于DA遗传距离构建的NJ聚类树显示,地理位置相邻的群体聚在一起。STRUCTURE分析413份参试的日本沼虾样本被分为2个理论种群,即上游歙县和休宁群体为一个理想种群,其余中下游的5个群体为另一个理想种群。日本沼虾的遗传多样性和遗传结构与所生存的地理位置具有相关性。

Genetic diversity and genetic structure of 7 wild stocks of oriental river prawn Macrobrachium nipponense in Qiantang River,i.e.Wen-yan,Fu-yang,Chang-kou,Tong-lu,Xin-an-jiang,She-xian and Xiu-ning,were investigated using 10 microsatellite DNA markers.The result showed that all the 10 loci were highly polymorphic.There was a trend that the level of genetic diversity of wild stocks in downstream and midstream were higher than the upstream ones＇.Sign test and Wilcoxon sign rank test results showed that the stocks in Qiantang River had no bottleneck effect,and the number of stocks had not declined recently.FST among stocks ranged from 0.0201 to 0.1069.Analysis of molecular variance（AMOVA） revealed that a higher portion（93.48%） of variations existed within individuals,while lower portion（6.52%） existed among stocks.FST and AMOVA analysis across all stocks and loci indicated the medium level of divergence among the stocks.The NJ clustering tree based on DA genetic distance demonstrated that the stocks of adjacent geographical position clustered together.413 individuals obtained from six wild stocks could be divided into two potential populations based on the genetic structure.This study demonstrated that genetic diversity and genetic structure of M.nipponense stocks were relevant to geographical position where they survived.