绥芬河三块鱼属“银滩头”洄游群体的分子鉴定

Molecular identification of Tribolodon “silver beachhead” migratory population in Suifen River

绥芬河三块鱼属洄游群体中"银滩头"的分类地位一直存在争议。利用DNA条形码COⅠ和基因标记(fst和mitfa)分析相结合的方法,对采自我国绥芬河的珠星三块鱼(Tribolodon hakonensis,40尾)、三块鱼(T.brandtii,38尾)和"银滩头"(34尾)及采自日本宇曾利山湖的珠星三块鱼(3尾),共计115尾个体进行了种质鉴定。线粒体COⅠ基因扩增结果显示,共获得单倍型11种,其中,珠星三块鱼独享5种,三块鱼独享5种,珠星三块鱼日本群体独享1种(Hap6),"银滩头"群体与珠星三块鱼共享1种,与三块鱼共享3种,聚类分析不支持"银滩头"群体为一个独立种。基因标记扩增结果显示,"银滩头"群体中兼具珠星三块鱼和三块鱼两种基因型。结合以上两种分析结果发现"银滩头"中存在珠星三块鱼与三块鱼的杂交个体。明确了"银滩头"群体的分类地位,即"银滩头"是由珠星三块鱼、三块鱼及二者的杂交个体组成的一个混合群体。研究结果为三块鱼属鱼类的分类、种质资源保护和野外增殖放流提供了科学依据。

The taxonomic status of “silver beachhead” in Tribolodon migratory population in Suifen River has always been controversial.In this study,we used DNA barcoding COⅠ and gene markers(fst and mitfa) to identify 115 individuals from Suifen River,including Tribolodon hakonensis(40),T.brandtii(38) and “silver beachhead”(34),and 3 individuals of T.hakonensis from Lake Osorezan,Japan.The results of mitochondrial COⅠgene amplification showed that a total of 11 haplotypes were obtained,of which 5 haplotypes were exclusive to T.hakonensis,5 haplotypes were exclusive to T.brandtii,and 1 haplotype(hap6) was exclusively shared by Japanese population of T.hakonensis,“silver beachhead” population shared 1 haplotype with T.hakonensis,and shared 3 haplotypes with T.brandtii.Cluster analysis did not support the “ silver beachhead ” population as an independent species.The results of amplification of two gene markers showed that “silver beachhead” population had both genotypes of T.hakonensis and T.brandtii.Combining the above two analysis results,it is found that there are hybrid individuals of T.hakonensis and T.brandtiiin “silver beachhead”.In conclusion,this study confirmed the taxonomic status of the“silver beachhead”population,that is,“silver beachhead” is a mixed population composed of T.hakonensis,T.brandtii and their hybrids.The results of this study provide a scientific basis for the classification,conservation of germplasm resources and wild release and enhancement of Tribolodon.