褐飞虱体内Arsenophonus、Wolbachia、Spiroplasma和Cardinium四种次生共生菌感染分析

Detection and analysis of four secondary endosymbiotic bacteria(Arsenophonus, Wolbachia, Spiroplasma and Cardinium) in the brown planthopper, Nilaparvata lugens(Homoptera:Delphaciade)

【目的】Arsenophonus、Wolbachia、Spiroplasma和Cardinium是广泛分布于昆虫体内的次生共生菌,能对寄主昆虫的生殖和发育生理产生影响,明确不同地理种群褐飞虱体内4种共生菌的感染和系统发育关系可为利用共生菌防治害虫提供技术依据。【方法】利用Arsenophonus特异性23S rRNA基因引物,Wolbachia、Spiroplasma和Cardinium各自的16S rRNA基因引物PCR检测广西10个地市、海南海口及上海、江苏南京、湖南长沙共14个地理种群褐飞虱雌、雄虫体内共生菌感染情况,并对扩增到的基因片段进行测序、构建系统发育树。【结果】不同地区2014年和2015年褐飞虱体内Arsenophonus感染率最高的分别为河池种群(30%)和长沙种群(20%)、PWolbachia感染率最高为河池种群(20%)和南京种群(30%),而Spiroplasma和Cardinium在褐飞虱各种群内均未检测到。序列比对和发育分析表明,褐飞虱体内Arsenophonus与同翅目昆虫白蜡虫Ericerus pela Chavannes体内感染的该菌关系最近;而感染Wolbachia菌的系统发育分析表明,除海南种群有一个个体感染Wolbachia菌A群外,其余种群感染的全部为B群;同时在所有感染两类共生菌的个体中并未发现共感染现象。【结论】不同地理种群褐飞虱感染Arsenophonus和Wolbachia两类共生菌的感染率并不一致;总体上褐飞虱雌虫Wolbachia感染率要高于雄虫,褐飞虱体内感染的两类共生菌与其它昆虫体内的共生菌序列高度一致或类似,且在所有检测的地理种群中均未发现有Spiroplasma和Cardinium感染。

[Objectives] Insects are often infected by the endosymbiotic bacteria Arsenophonus, Wolbachia, Spiroplasma and Cardinium and the detection and analysis of these bacteria in different geographic populations of the brown planthopper could provide information helpful for the control of this pest. [Methods] Specimens from 14 geographic brown planthopper populations were collected in 2014 and 2015, and their endosymbiotic bacteria identified with PCR. Phylogenetic trees were constructed using Mega5.01 based on variation in the 23S rRNA gene of Arsenophonus and the 16S rRNA gene of Wolbachia detected in brown planthopper specimens. [Results] Spiroplasma and Cardinium were not detected in any samples. In 2014, the highest Wolbachia and Arsenophonus infection rates, 20% and 30%, respectively, were detected in the Hechi population. In 2015, the highest Wolbachia and Arsenophonus infection rates, 30% and 20%, respectively, were detected in the Nanjing and Changsha populations. Phylogenetic analysis revealed that Arsenophonus detected in the brown planthopper populations sampled was most closely related that found in the Homoptera. With the exception of the Haikou population, which was infected with the Wolbachia A supergroup, all other brown planthopper populations were infected with the Wolbachia B supergroup. There was no evidence of co-infection by Arsenophonus and Wolbachia. [Conclusion] The infection rates of Arsenophonus and Wolbachia varied among different geographical populations of the brown planthopper. More females were infected with Wolbachia than males. The Arsenophonus 23S rRNA gene and the Wolbachia 16S rRNA genes found in brown planthoppers are similar to those in other insects. There was no evidence of co-infection of by Arsenophonus and Wolbachia in the brown planthopper populations sampled, nor were Spiroplasma and Cardinium detected in any of the sampled populations.