油松毛虫亚居群遗传结构的SSR分析

Genetic Structure of Five Sub-Populations of Dendrolimus punctatus tabulaeformis (Lepidoptera:Lasiocampidae) Detected with Microsatellite Markers

采用SSR分子标记技术对平泉县5个油松毛虫亚居群进行遗传多样性和遗传分化研究。结果显示:8对SSR引物对5个油松毛虫亚居群的扩增片段长度范围为78～430bp,检测到的等位基因数为1～6个;种群总体水平多态位点比率P=87.50%,平均有效基因数A=3.1250,平均期望杂合度He=0.4747,种群平均遗传距离为0.0703～0.4197;遗传分化度Fst=0.2159,基因流Nm=0.9081。由此可以得出在5个天然油松毛虫亚居群中,天然油松纯林居群内杂合度要比其他居群高;油松毛虫亚居群间已发生明显的遗传分化,基因交流较少,遗传漂变已经成为导致该物种种群分化的主要原因之一;油松毛虫亚居群遗传结构产生变异推测是由于常年化学防治和单一寄主植物造成的选择压力的影响。

In this paper,population genetic variability and genetic structure of five sub-populations of Dendrolimus punctatus tabulaeformis（Lepidoptera：Lasiocampidae）were analyzed by using microsatellite markers.Eight microsatellite loci were used to detecte genetic structure of five sub-populations of D.punctatus tabulaeformis.The fragments lengths were from 78 bp to 430 bp.For each locus,1-6 alleles were amplified.We found the genetic variability level was relatively high in all five sub-populations,as shown by P=87.50%,A= 3.125 0,He= 0.474 7,Ds= 0.070 3-0.419 7,Fst= 0.215 9,Nm= 0.908 1.In this study,the expected heterozygosity（He）values showed that the genetic diversity of the subpopulation in pure Pinus tabulaeformis forest was higher than that of other sub-populations.According to the heredity parameters,gene flow was low and genetic drift was one of primary factors to lead to the genetic differentiation among five sub-populations of D.punctatus tabulaeformis.Overall,population genetic subdivision is high and the differentiations are also significant among sub-populations.The differences would probably be induced by local selection pressure of the insecticide treatments and the pure host food.