基于形态和Cytb序列的短颌鲚种群遗传分化研究

Genetic Differentiation of Shortjaw Tapertail Anchovy Coilia brachygnathus Population Based on Cytb and Morphology

为探明鄱阳湖与洪泽湖短颌鲚的种群遗传分化情况,利用形态度量学和线粒体细胞色素b(Cytb)序列,研究鄱阳湖的都昌、瑞洪及洪泽湖的高良涧、临淮4个水域短颌鲚种群的遗传分化。短颌鲚26个性状参数的聚类分析结果显示,都昌种群与瑞洪种群首先聚为一支,然后与临淮种群、高良涧种群相聚;主成分分析结果显示,前3个主成分总贡献率为65.12%;判别分析结果显示,都昌种群、瑞洪种群、高良涧种群与临淮种群的判别准确率分别为91.40%、80.00%、84.60%和82.50%。上述形态分析表明,同一湖区内部种群的形态差异较小,而不同湖区间的种群存在较大的形态差异。Cytb序列遗传分析显示,60条序列共有33个单倍型;基因多态性(H_(d))总计为0.957±0.013,核苷酸多态性(P_(i))总计为0.00462±0.00047;4个种群间遗传分化指数(F_(st))为0.00362~0.60873,基因流为0.16069~68.81077;中性检验结果显示,4个种群的Tajima'sD值、Fu'sF_(s)值均为负数;单倍型分布以及遗传距离构建的系统发育树均分为鄱阳湖和洪泽湖两支。上述结果表明,两个湖泊间的短颌鲚种群产生了显著的遗传分化。

To investigate the population genetic differentiation of shortjaw tapertail anchovy Coilia brachygnathus in Poyang Lake and Hongze Lake,the genetic diversity of shortjaw tapertail anchovy populations in Duchang(DC)and Ruihong(RH)waters of Poyang Lake,and Gaoliangjian(GLJ)and Linhuai(LH)waters of Hongze Lake was studied by using morphometry and mitochondrial cytochrome b(Cytb)sequences.Clustering analysis of 26 trait parameters showed that DC population and RH population first clustered into one branch,and then clustered with LH population and GLJ population.The total contribution rate of the first three principal components in principal component analysis was 65.12%.The results of discriminant analysis showed that the discriminant accuracy of DC,RH,GLJ and LH populations were 91.40%,80.00%,84.60%and 82.50%,respectively.The above morphological analysis showed that the morphological differences of populations in the same lake area were small,but there were great morphological differences among different lakes.Genetic analysis of Cytb sequence showed that there were 33 haplotypes in 60 sequences,with total gene polymorphism(H_(d))of 0.957±0.013,and the total nucleotide polymorphism(P_(i))of 0.00462±0.00047.The genetic differentiation index(F_(st))of the four populations was 0.00362—0.60873,and the gene flow was 0.16069—68.81077.The results of neutral test showed that the D and F_(S)values of the four populations were negative.The phylogenetic trees constructed by haplotype distribution and genetic distance were divided into two branches:Poyang Lake and Hongze Lake.The findings indicated that there was significant genetic differentiation in the population of shortjaw tapertail anchovy between the two lakes.