贵州省3个地理种群大鲵的遗传多样性及遗传结构

Genetic Diversity and Genetic Structure of Giant Salamander from Three Geographical Populations in Guizhou Province

测定了贵州省贵定县、松桃县和江口县共36尾大鲵的mtDNA D-loop区部分序列,探究贵州省内不同地理种群大鲵的遗传多样性及遗传结构。结果显示,36个序列的碱基平均组成为T(33.8%)、C(22.2%)、A(30.0%)、G(14.0%),其中T的含量最高,C的含量最低;A+T含量(63.8%)显著高于G+C含量(36.2%)。江口种群核苷酸多样性指数为0.00551,贵定种群及松桃种群的核苷酸多样性指数均为0。3个地理种群相比,江口种群大鲵遗传多样性水平较高。3个种群的平均遗传距离为0.00436,其中贵定种群与江口种群达到了种群的分化水平(P<0.01)。遗传结构分析结果表明,贵定种群先与松桃种群聚为一支,再与江口种群聚为一支。3个种群大鲵的整体遗传多样性水平低,遗传分化程度也低。

A research on mtDNA D-loop region partial sequence was studied in 36 giant salamanders Andrias daudianus samples collected from Guiding county,Songtao county and Jiangkou county in Guizhou province.The results showed that the average contents of the four bases were 33.8%in T,22.2%in C,30.0%in A and G in 14.0%,with the maximal T content,and the minimal C content;A＋T content was63.8%,significantly higher than that in G＋C content（36.2%）.The nucleotide diversity（π）of the Jiangkou populations were 0.00551,and the nucleotide diversity（π）of the Guiding and Songtao population was 0.Compared with the three geographical populations,the genetic diversity level of giant salamander in Jiangkou county population was higher.The average genetic distance of three populations was 0.00436,and the Guiding and the Jiangkou population reached the population differentiation level（P〈0.01）.Analysis of the genetic structure indicated that Guiding and Songtao populations were clustered for first,and then clustered with Jiangkou popultion.The overall genetic diversity of these populations of giant salamander was low,and the genetic differentiation of these populations was low.