基于线粒体Cytb基因的嗜卷书虱和嗜虫书虱种群遗传结构的比较研究.doc

  Comparative population genetics of Liposcelis bostrychophila and L. entomophila, from China inferred by  5 10 15 20 25 30 35 40 45 analysis of the mitochondrial Cytb Gene# WEI Dandan, WU Jingjing, DOU Wei, WANG Jinjun** (Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, ChongQing 400716) Abstract: The psocids Liposcelis bostrychophila and L. entomophila (Psocoptera: Liposcelididae), are two major pests of stored grain and commonly occur on a wide range of stored products. Increasingly, psocids have gained recognition of their importance due to their feeding on stored grains, contaminating food and agricultural commodities. Psocids are difficult to control and exhibit high levels of resistance to various insecticides. Previous research has mainly focused on psocid physiology, biochemistry, and basic biology in grain storage systems. However, the population genetic structure has not been well categorized, which may be useful for understanding the distribution of resistance gene frequencies among psocid populations, gene flow patterns, dispersal of source populations, and the resultant genetic structure among populations. We generated mtDNA sequence data for 148 L. entomophila individuals from ten collecting locations and 103 L. bostrychophila individuals from eight locations in China. Population genetic analyses indicated that the obligatory parthenogenetic L. bostrychophila had high genetic diversity, and is higher than the genetic diversity of sexually reproducing psocid L. entomophila. Both species had a significant genetic structure and significant genetic differentiation existed amongst the populations. The Mantel test indicated that there was no evidence for isolation-by-distance for both species. The neutrality test revealed that the two species might have undergone population expansions in the past in the sampled areas. In addition, population differentiation of both psocids may mainly due to o