新疆地区亚洲玉米螟中Wolbachia共生菌的检测和鉴定

Detection and identification of Wolbachia in the Asian corn borer,Ostrinia furnacalis( Lepidoptera: Crambidae) in Xinjiang,northwestern China

【目的】探究我国新疆地区亚洲玉米螟Ostrinia furnacalis种群中Wolbachia共生菌的感染情况,明确Wolbachia的感染类型及分布模式。【方法】对采集自新疆维吾尔自治区的15个亚洲玉米螟地理种群进行了Wolbachia感染率检测,并分别对感染个体中的wsp,ftsZ,gatB,coxA,hcpA和fbpA6个基因片段进行亚克隆和测序。分别利用wsp序列和多位点序列分型系统(multilocus sequence typing,MLST)对Wolbachia感染类群进行系统发育分析及分型分析。【结果】在15个供试亚洲玉米螟种群中,Wolbachia感染率为0~40.0%(5个种群中未检测到感染个体),平均感染率为11.1%。发现共感染了两种Wolbachia株系,分别命名为wOfur1和wOfur2,其中wOfur1属于A大组,wOfur2属于B大组,分别对应MLST序列型为ST352和ST37。在感染种群中,昌吉(CJ)、阜康(FK)、玛纳斯(MNS)和奇台(QT)4个种群感染了wOfur1和wOfur2两种株系,而在其余6个种群即和田(HT)、库尔勒(KEL)、莎车(SC)、疏勒(SL)、乌鲁木齐(UM)和新和(XH)中仅发现感染了wOfur2株系,并在MNS种群中发现了超感染现象,wOfur1和wOfur2两株系的平均感染率分别为1.2%和10.3%。基于wsp序列及MLST等位基因谱系统发育分析表明wOfur2株系与其他昆虫宿主中具有杀雄和诱导胞质不亲和作用的Wolbachia株系具有很近的亲缘关系。【结论】我国新疆地区亚洲玉米螟所感染的Wolbachia两种株系wOfur1和wOfur2在亚洲玉米螟不同种群中的感染率和分布范围具有明显差异,wOfur2株系的感染率高于wOfur1株系,且wOfur2株系在亚洲玉米螟种群中分布更广。

【Aim】The objective of this study is to investigate the diversity and prevalence patterns ofWolbachia in populations of the Asian corn borer,Ostrinia furnacalis in Xinjiang,northwestern China.【Methods】Wolbachia infection rates in 15 geographical populations of O. furnacalis collected from Xinjiang Uygur Autonomous Region were detected,and six genes including wsp,fts Z,gat B,cox A,hcp A and fbp A were subcloned and sequenced from each infected individual. Phylogenetic analysis and sequence typing of Wolbachia strains infecting O. furnacalis were performed based on wsp sequences and by multilocus sequence typing system（ MLST）,respectively. 【Results】The Wolbachia infection rates in the 15 O. furnacalis populations ranged from 0 to 40. 0%,with an average infection rate of 11. 1%（ no infected individual was detected in five populations）. Phylogenetic trees based on wsp sequences and MLST allelic profiles indicated that two Wolbachia strains,i. e.,wOfur1 and wOfur2,infected O.furnacalis populations in Xinjiang, which were assigned to the supergroup A and supergroup B,corresponding to MLST sequence type ST352 and ST37,respectively. Among the tested populations,four populations,i. e.,populations from Changji（ CJ）,Fukang（ FK）,Manasi（ MNS） and Qitai（ QT）,were infected with both strains,and six populations,i. e.,populations from Hotan（ HT）,Korla（ KEL）,Yarkant（ SC）,Shule（ SL）,Urumqi（ UM） and Xinhe（ XH）,were only infected with wOfur2. The average infection rates of wOfur1 and wOfur2 were 1. 2% and 10. 3%,respectively. Superinfection was found in MNS population tested. wsp and MLST clustering showed a closely genetic relationship between wOfur2 and several Wolbachia strains which had been proved to induce cytoplasmic incompatibility and male-killing to their insect hosts. 【Conclusion 】The two Wolbachia strains wOfur1 and wOfur2 showdistinct differences in the infection rate and prevalence pattern in O. furnacalis populations in Xinjiang.Infection with wOfur2 is more frequent and widespread than that with wOfur1 in O. furnacalis populations.