[目的]为研究理县高原鳅不同地理种群的遗传多样性和群体结构,进一步利用理县高原鳅的遗传种质资源并对其野生群体进行保护,获取长江流域理县高原鳅种群结构信息.[方法]对大渡河理县高原鳅体重和体长组成、体长-体重关系进行研究,并利用线粒体DNA控制区D-loop序列,对理县高原鳅4个地理种群共117个个体进行遗传结构变异分析.[结果]理县高原鳅体重和体长的回归方程为y=0.0123x29734,b值为2.9734,接近3,表明目前理县高原鳅生长状态良好.利用线粒体分子标记,在4个种群个体中共扩增获得878 bp的D-loop同源序列,包含28个单倍型和32个多态性位点,4个种群之间无共享单倍型.4个理县高原鳅群体的单倍型多样度在0.637~0.921,核苷酸多样性在0.000 91~0.005 70.通过分析遗传距离发现,金川县和丹巴县、泸定县和石棉县之间的理县高原鳅群体未发生遗传分化,而泸定县与金川县或丹巴县、石棉县与金川县或丹巴县之间的理县高原鳅群体均存在显著的遗传分化.通过构建NJ进化树发现,117个理县高原鳅个体在进化树上形成2个独立分支,与各地理种群的遗传分化结果一致.[结论]建议将大渡河金川县和丹巴县理县高原鳅种群作为一个整体进行管理和保护,石棉县和泸定县也作为一个整体进行管理和保护,而金川县和丹巴县、石棉县和泸定县的种群建议分开管理和保护.
[Objective]The present paper aimed to study the genetic diversity and population structure of different geographical populations of Triplophysa lixianensi in Lixian county,and to further utilize the genetic germplasm resources of T.lixianensi in Lixian county so as to protect its wild population,the population structure of T.lixianensi in the Yangtze River Basin was investigated in the present study.[Method]In the study,length composition,body weight composition,length-weight relationships and genetic structure variation of 117 T.lixianensis in four regions of Dadu River were analyzed,and the genetic diversity analysis was performed using D-loop control region of mitochondrial DNA.[Result]The regression equation of body weight and body length was y=0.0123x2.9734.The b value was 2.9734 which was close to 3,indicating that the current growth state was acceptable.A total of 32 variable sites and 28 haplotypes were identified in 878 base pairs of 117 individuals.There was no shared haplotypes among the individuals from four regions.The haplotype diversity of four populations ranged from 0.637 to 0.921,and the nucleotide polymorphisms of four populations ranged from 0.000 91 to 0.005 70.There was no genetic differ-entiation between Jinchuan population and Danba population,Luding population and Shimen population,but there was significant genetic differentiation between Luding population and Jinchuan population or Danba population,and between Shimian population and Jinchuan pop-ulation or Danba population.By constructing the NJ tree,we found that 117 individuals of T.lixianensis formed two independent branches in the evolutionary tree,which was consistent with the genetic distance results of each geographical population.[Conclusion]We suggest that Jinchuan and Danba populations of Dadu River should be managed and protected as a whole protection unit,and that Shimian and Luding populations should also be managed and protected as a whole,while Jinchuan and Danba populations,Shimian and Luding populations should be managed and protected separately.