Endosymbiont detection and phylogeny of Wolbachia in Diaphorina citri and Dialeurodes citri

Author of the article:SUN Xiu-Xin1 ** SHI Pei-Qiong1 XU Wei-Ming1 QIN Zhen-Qiang2 REN Shun-Xiang1 QIU Bao-Li1 ***

Author's Workplace：1. Key Laboratory of Bio-pesticide Innovation and Application, Engineering Technology Research Center of Agricultural Pest Biocontrol of Guangdong Province, Department of Entomology, South China Agricultural University, Guangzhou 510640, China; 2. Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China

Key Words：citrus psyllid, citrus whitefly, endosymbionts, Wolbachia, phylogeny

Abstract：

 [Objectives]  To survey the infection rates of different symbiotic bacteria in different geographic populations of the citrus psyllid and citrus whitefly, and to analyze the phylogenetic relationships between different Wolbachia populations in order to provide endosymbiont-based scientific support for the continuous management of the citrus psyllid and citrus whitefly. [Methods]  Endosymbionts in citrus psyllids from Guangzhou, Zhanjiang, Xiamen, Guilin and Nanning, and citrus whiteflies from Guangzhou, were detected using PCR. The phylogenetic relationships of Wolbachia were analyzed using a phylogenetic tree constructed with MEGA 5.0 based on the Wolbachia wsp and MLST genes detected in citrus psyllids and citrus whiteflies. [Results]  All citrus psyllid and whitefly populations in the current study were infected with the primary endosymbiont Portiera and the secondary endosymbionts Wolbachia, Cardinium, Rickettsia, but infection rates of these three endosymbionts varied between different geographical populations. Arsenophonus was only detectable in Guangzhou and Zhanjiang psyllid populations. Phylogenetic analysis revealed that Wolbachia endosymbionts in all citrus psyllid and whitefly populations were very similar and belonged to the Con group of the Wolbachia B supergroup. [Conclusion]  The species and infection rates of endosymbionts varied among different geographical populations of the citrus psyllid and whitefly. There is no apparent coevolutionary relationship between Wolbachia and its psyllid hosts. Indeed, the high homology of Wolbachia in different hosts suggests plant-mediated horizontal transmission of Wolbachia between different psyllid hosts.