The phylogeny of south China populations of Bemisia tabaci and Encarsia parasitoid wasps in relation to infectionwith the Cardinium endosymbiont
Author of the article:YIN Xiang-Jie** SUN Xiu-Xin Muhammad Z Ahmed REN Shun-Xiang QIU Bao-Li***
Author's Workplace：Department of Entomology, South China Agricultural University; Engineering Research Center of Biological Control, Ministry of Education,Guangzhou 510640, China
Key Words：Bemisia tabaci, aphelinid parasitoid, Cardinium, endosymbiont, coevolution, horizontal transmission
Abstract： [Objectives] To investigate the relationship between the phylogeny of four Bemisia tabaci cryptic species (six populations), two species of Encarsia parasitoid (two populations), and infection with the Cardinium endosymbiont. [Methods] Whitefly and parasitoid samples were collected from Guangzhou, Zhaoqing, Nanning, Kunming and Xiamen, respectively. The Cardinium endosymbiont was first detected by PCR with special primers. Its cophylogeny with whitefly and parasitoid hosts was analyzed based on its 16S rRNA sequences and hosts’ mt COⅠ sequences. [Results] Whitefly B. tabaci AsiaII1 and AsiaII7 from Guangzhou, MEAM1 from Nanning and Zhaoqing, Mediterranean from Xiamen and Kunming, as well as Encarsia formosa and E. bimaculata, were all infected with Cardinium. Infection rates of the B. tabaci Mediterranean, AsiaII1 and AsiaII7 strains were much higher (65.2%-92.5%) than in the B. tabaci MEAM1 and two Encarsia parasitoids (16.7%-18.6%). No copholygenetic relationships were found between Cardinium and the different whitefly and parasitoid hosts. However, the sequence homology of Cardinium from B. tabaci populations from China and seven other countries and the two Encarsia parasitoids was > 98.0%. [Conclusions] There is a high probability for Cardinium to be horizontally transmitted between different whitefly populations and parasitoids may be an intermediate host for the horizontal transmission of Cardinium.