山西不同地域菜粉蝶RAPD遗传多样性

采用RAPD技术分析了山西省菜粉蝶5个地域种群间的遗传多样性和遗传关系,用筛选出的12对引物扩增共得到143条带,其中127(88.8%)条带具有多态性,5个种群变异程度由大到小的顺序为:大同的(76.3%)＞太原的(74.7%)＞长治的(74.5%)＞代县的(73.7%)＞夏县的(70.7%).Shannon's信息指数分析结果显示大多数变异发生在种群内(73.7%).种群间的Nei's遗传距离较低(均＜0.1).用UPGMA和 Neighbor-joining做的基于RAPD标记的Nei's遗传距离的聚类图显示,各种群内的个体首先聚在一起,种群之间有一定分化,5个地域种群间较远距离的代县种群与夏县种群遗传关系最近并优先相聚.经过对试验结果的分析讨论认为:环境类型及其生态条件对山西省菜粉蝶地域种群的遗传多样性和遗传变异产生了重要的影响,其中农药的施用对菜粉蝶种群遗传结构的影响有可能是深刻的.

RAPD analysis of genetic diversity of five populations of Pieris rapae (L.) in Sanxi Province, China

RAPD markers were applied to analyze the genetic divergence of five populations of butterfly cabbage white (Pieris rapae) in Shanxi, China. The populations were sampled from vegetable farms at five representative basin areas from north to south of Shanxi, i.e. Youyu in Datong Basin, Daixian in Xinding Basin, Taiyuan in Taiyuan Basin, Zhangzi in Shangdang Basin, and Xiaxian in Yuncheng Basin. Genomic DNA of seventy-five individuals were extracted from leg muscle using Phenol-Chloroform method and then amplified using 12 pre-determined random primers (10 bp) which generated a total of 143 clear and reproducible bands. In terms of the number of polymorohic loci, the rank is as follows: Datong′ (76.3%) > Taiyuan′ (74.7%) > Changzhi′ (74.5%) > Daixian′ (73.7%) > Xiaxian′(70.7%). The analysis of Shannon′s Index showed moderate polymorphism among the populations (Hsp = 3.9507;Hpop =2.9001). The dendograms based on Nei′s genetic distance using UPGMA and Neighbor-Joining showed high genetic similarity among the five populations. It is noted that Daixian population was closer with Xiaxian population in spite of large geographic distance. Considering the populations were from geographically distant basins the cluster analysis did not show distinct correlation trend between geographic and genetic distance, suggesting the likely gene flow among the populations. Moreover the frequent use of pesticides in farms may have also imposed pressure of artificial selection on the populations to evolve to a more uniform pattern in Shanxi Province.