呼玛河3种茴鱼遗传分化及属内地位的微卫星分析

茴鱼属（Thymallus）是黑龙江水系特有的珍稀濒危冷水性鱼类,本研究利用6对微卫星引物,对采自黑龙江上游呼玛河同域分布的黑龙江茴鱼（T.grubii）、下游黑龙江茴鱼（T.tugarinae）及待定名种（T.sp.）3种茴鱼的遗传多样性进行了比较研究,以探讨其种群遗传结构、分化水平及分类学地位,为制定保护管理策略提供遗传学理论依据。结果显示,黑龙江茴鱼、下游黑龙江茴鱼和待定名种的平均等位基因数（Na）分别为17.3、18.2和15.3,平均杂合度（H）分别为0.9112、0.9190、0.8492,多态信息含量（PIC）为分别为0.8900、0.8980和0.8250,种群中的特有等位基因数分别为34、37和43。黑龙江茴鱼与下游黑龙江茴鱼的遗传距离（Ds）最小（0.9617）,下游黑龙江茴鱼与待定名种最大（1.8427）,3种茴鱼的Fst为0.1575（P〈0.01）,远大于黑龙江茴鱼、下游黑龙江茴鱼的不同地理种群间的遗传分化水平。研究表明,黑龙江上游3种茴鱼具有很高的遗传多样性水平,3个种间产生显著的遗传分化,结合3种茴鱼种间稳定而显著的形态学特征差异及其地理分布现状,支持黑龙江上游呼玛河同域分布的3种茴鱼在属内各为独立种的分类学地位。

Genetic differentiation and taxonomic status of three species in grayling Thymallus in Huma River by microsatellite analysis

The genetic structure and taxonomy of grayling as native specific and important cold freshwater fish were studied in three species（T.grubii,T.tugarinae and T.sp.） from Huma River by microsatellite analysis.to supply genetics theoretical basis for management,and conservation strategy.The results showed that the numbers of mean alleles（Na） were found to be 17.3,18.2 and 15.3,mean heterozygosity（H） 0.9112,0.9190 and 0.8492,and the average polymorphism information content（PIC） 0.8900,0.8980 and 0.8250 for T.grubii,T.tugarinae and T.sp.populations,respectively.The population specific allele number were found to be 34,37 and 43 for T.grubii,T.tugarinae and T.sp.populations,respectively.The Ds value between T.grubii and T.tugarinae was showed to be 0.9617,between T.tugarinae and T.sp 1.8427,and the Fst values between populations 0.1575（P0.01）.There was significantly higher genetic divergence level among the three species of Thymallus than in the populations of T.grubii and T.tugarinae,indicating that the morphological characteristic of three species of Thymallus were so different that the grayling in Huma River are distinct species in genus Thymallusa.