Abstract:

 Wolbachia is a common and widespread group of symbiotic bacteria found in arthropods, which is transmitted through the egg cytoplasm and can manipulate reproduction in their hosts in various ways. So, it has important potential significance on the research of evolution of arthropods and may be used in pest bio-control. Taking the Asian citrus psyllid (Diaphorina citri), the vector of the Huanglongbing(HLB) pathogen, as the research object, we detected the natural populations of Diaphorina citri from five areas, i.e., Beihai and Liuzhou in Guangxi, Shenzhen and Yangchun in Guangdong, and Fuzhou in Fujian, based on PCR amplification, cloning and sequencing of 16S rRNA, ftsZ and wsp genes. The obtained sequences were aligned with the published ones in database of NCBI, and the phylogenetic relationships among Wolbachia types found in D. citri and other insect species were analyzed. The results indicated that all the five populations of D. citri were infected by Wolbachia. The three gene sequences of Wolbachia and the phylogenetic tree analysis showed that Wolbachia population in D. citri belongs to supergroup B.  Further phylogenetic analysis based on the wsp gene sequences showed that the Wolbachia of D. citri belongs to Con subgroup. The 16S rRNA, ftsZ and wsp gene sequences were almost identical in the five geographic populations, respectively, and the identity is up to 99%, showing that these three gene sequences of Wolbachia in different geographic populations of D. citri had no significant difference. The results can provide useful information for understanding evolution of citrus psyllids and their integrated control.

Key words: Diaphorina citri, Wolbachia, 16S rDNA, ftsZ, wsp, phylogeny, Huanglongbing(HLB)