引进天敌莲草直胸跳甲的遗传多样性

Genetic diversity of introduced natural enemy Agasicles hygrophila(Coleoptera:Chrysomelidae).

我国从美国引进天敌昆虫莲草直胸跳甲防治喜旱莲子草已有20多年历史.本研究采用随机引物扩增多态性DNA(RAPD)分析方法,对引入我国的4个莲草直胸跳甲地理种群(广州、重庆、昆明、福州)的遗传多样性情况进行分析,并以美国佛罗里达种群为参照,从分子水平上揭示其种群的遗传分化及其与环境之间的关系.从111条随机引物中选取13条条带清晰、重复性好的引物对5个种群的25个样本进行扩增.结果表明:总多态位点百分率为42.0%,其中美国佛罗里达种群的多态位点百分率显著高于我国的4个地理种群;25.5%遗传分化发生在4个群体间;对各地理种群间的遗传距离采用非加权配对算术平均法(UPG-MA)进行聚类分析发现,遗传距离与种群空间分布距离呈正相关.

Flea beetle Agasicles hygrophila Selman Vogt,the most effective natural enemy of alligator weed Alternanthera philoxeroideis,is originated from South America,and has been introduced into China for more than 20 years to control the weed.In this study,the technique of random amplification of polymorphic DNA（RAPD） was applied to assess the genetic diversity of four A.hygrophila geographic populations in Guangzhou,Chongqing,Kunming,and Fuzhou of China,and,taking the population in Florida of US as the reference,the relationships between the genetic differentiation and geographic differentiation among and within the populations were explored at molecular level.Thirteen primers that produced clear and reproducible products were selected from 111 random primers to amplify the 25 samples of the five A.hygrophila populations.The total polymorphic rate was 42.0%,and the polymorphic rate of Florida population was significantly higher than that of four China populations.The genetic differentiation among the four China populations was 25.5%.The cluster analysis by UPGMA indicated that there was a positive correlation between the genetic distance and geographic distance of different A.hygrophila geographic populations.