小麦和大豆蚜虫中内共生菌Wolbachia的感染检测和系统发育分析

Wolbachia是一类在节肢动物中广泛感染的胞内共生菌。为了了解其在我国蚜虫中的感染情况， 本研究通过扩增wsp基因片段对采集自我国多个地区的3种小麦蚜虫（荻草谷网蚜Sitobion miscanthi、 麦二叉蚜Schizaphis graminum和禾谷缢管蚜Rhopalosiphum padi）和1种大豆蚜虫（大豆蚜Aphis glycines）样品进行了内共生菌Wolbachia的感染检测。结果显示： 3种小麦蚜虫中均未检测出Wolabchia。大豆蚜也仅在采集自北京和杭州的种群中发现了Wolbachia的感染， 感染率分别为95.8%和22.9%， 并且所检测的个体均为单株系感染。wsp基因序列的比对分析显示， 大豆蚜感染的Wolbachia株系与多个亲缘关系较远的昆虫物种中所感染的Wolbachia株系间具有高度一致的基因序列。wsp基因序列构建的系统发育关系和序列一致性均表明大豆蚜感染的Wolbachia株系属于B大组CauB组。本研究为今后探讨Wolbachia在我国蚜虫中的寄主范围和株系多样性提供了数据支持。

Detection and phylogenetic analysis of Wolbachia in wheat and soybean aphids in China

 Wolbachia is a group of intracellular symbionts ubiquitous in arthropods. To investigate the Wolbachia infection in Chinese aphids, we amplified the wsp gene of Wolbachia in different geographical populations of three wheat aphids (Sitobion miscanthi, Schizaphis graminum and Rhopalosiphum padi) and one soybean aphid (Aphis glycines) in this study. The results showed that Wolbachia was not detected in the three wheat aphids. In A. glycines, Wolbachia was only detected in two geographical populations of Beijing and Hangzhou, with the infection rates of 95.8% and 22.9%, respectively. Moreover, the sequenced samples were infected with single Wolbachia strain. The Blastn search results showed that wsp gene sequences are similar among Wolbachia strains isolated from A. glycines and from some distantly related host insect species. The wsp gene phylogeny revealed that Wolbachia strains isolated from A. glycines belong to Wolbachia B supergroup, CauB group. This study provides the data for further investigation on host range and strain diversity of Wolbachia in Chinese aphid species.