中国大鲵5个野生种群的AFLP分析

AFLP Analysis of Five Natural Populations of Andrias davidianus

采用AFLP技术对中国大鲵四川、贵州、湖北、陕西及河南五个野生种群的遗传多样性和遗传分化水平进行了评估。9对引物组合在5个野生种群中共扩增出507条带,其中多态性条带为354。多态位点比例(69.82%)、香农信息指数(0.362 9)和基因多样性指数(0.241 4)等参数均较高,显示中国大鲵遗传多样性水平较为丰富。AMOVA分析发现,中国大鲵遗传多样性绝大部分位于种群内(97.94%)。种群间遗传分化较弱(Фst=0.021,P<0.001)。根据种群间遗传距离构建的UPGMA树基本依照流域进行聚类,结合化石证据,推测中国大鲵由北向南进行扩散。

Genetic diversity and differentiation of natural populations of Andrias davidianus in Sichuan,Guizhou,Hubei,Shanxi and Henan was comprehensively determined using AFLP markers.Sixty individuals from five natural populations were used in AFLP analyses.Nine primer pairs in AFLP analyses produced 507 scorable bands,of which 354 were polymorphic.Three genetic diversity parameters： the percentage of polymorphic loci（69.82%）,the Shannon＇s information index（0.362 9） and the Gene diversity（0.241 4） all indicated that A.davidianus was with substantial variation.High level of genetic diversity of A.davidianus agreed with its life history traits and geographical distribution.Most of genetic diversity resided within populations（97.94%） in AMOVA analyses.A low genetic differentiation was characterized by Фst（Фst = 0.021,P〈0.001）.In the UPGMA dendrogram based on the genetic distance,A.davidianus populations were separated into two major clusters.A.davidianus was supposed to disperse southward from north with the salamander fossil proof.