我国斑鳜六个群体mtDNA Cyt b序列的遗传变异

采用PCR技术扩增了鸭绿江、海河、长江、钱塘江、闽江、西江6个群体31尾斑鳜(Sinipercascherzeri)mtDNACytb基因的部分序列。在长度为781bp的同源序列中,共检测到78个变异位点,占分析位点数的9.6%,碱基替换大都发生在密码子的第三位点上;在31个体中共检出16种单倍型。鸭绿江、海河群体与长江、钱塘江、闽江、西江群体间的遗传距离较大。分子方差分析表明,斑鳜6个群体间总的遗传分化水平FST为0.9307(P<0.01),差异极显著。构建的NJ分子系统发育树表明,海河群体和鸭绿江群体构成了一支北方群体;长江群体、闽江群体和西江群体构成了南方群体;而钱塘江群体单独聚为一支。这表明我国斑鳜不同地理群体间已产生明显的遗传分化,但未与其自然地理分布格局呈完全对应关系。

Genetic Variation of the Mitochondrial DNA Cyt b Among Six Populations of Siniperca scherzeri in China

The mitochondrial DNA Cyt b of 31 Siniperca scherzeri collected from the Yalujiang River, Haihe River, Yangtze River, Qiantangjiang River, Minjiang River and Xijiang River were amplified and partially sequenced using the PCR technique. The results showed that 78 nucleotide sites were variable along 781 bp length of homologous sequence (9.6%), base substitutions happened mostly at the third codon position, and sixteen haplotypes were detected in 31 individuals. Genetic distances between the Yalujiang, Haihe population and the Yangtze, Qiantangjiang, Minjiang and Xijiang population were higher. The analysis of molecular variance (AMOVA) supported the conclusion that there was significant genetic differentiation between these six geographical populations (F_ ST =0.9307, P<0.01). A neighbour joining tree showed that the Yalujiang and Haihe population formed the northern clade and the Yangtze, Minjiang and Xijiang populations formed the southern clade. The Qiantangjiang population formed an independent clade instead of merging into the southern clade. The phylogenetic relationship revealed by the Cyt b sequence was not consistent with the species' geographical distribution patterns.