烟粉虱复合种内共生菌多样性及其生物学意义

Diversity of endosymbionts in Bemisia tabaci (Gennadius) complex and their biological implications

烟粉虱复合种Bemisiatabaci(Gennadius)complex内共生菌的种类可分为5类:变形菌门(Proteobacteria)γ变形菌纲的初级内共生菌CandidatusPortieraaleyrodidarum和次级内共生菌,变形菌门α变形菌纲Wolbachia属细菌,衣原体门(Chlamydiae)衣原体纲细菌CandidatusFritscheabemisiae以及拟杆菌门(Bacteroidetes)类噬胞细菌(Cytophagalikeorganism,CLO)。系统发育分析表明,烟粉虱初级内共生菌分为2支,一些初级内共生菌和宿主系统发育并不严格一致;次级内共生菌分为3支,一些次级内共生菌可能存在水平传播或多次侵入的现象。上述5类内共生菌在烟粉虱不同生物型地理种群内的分布存在差异。B型烟粉虱可能具有独特的初级、次级内共生菌,并且不含有或很少含有Wolbachia属细菌、衣原体纲细菌CandidatusFritscheabemisiae以及类噬胞细菌(CLO)。最后探讨了不同内共生菌对烟粉虱宿主的生物学意义及其研究方向。

There are about 5 kinds of endosymbionts in Bemisia tabaci （Gennadius） complex including primary endosymbionts, secondary endosymbionts, Wolbachia, Candidatus Fritschea bemisiae and Cytophaga-likeorganism. Phylogenetic analysis showed that primary endosymbionts in B. tabaci complex could be divided into two clades based on the 16S rDNA sequences. The phylogeny of primary endosymbionts in B. tabaci was not strictly congruent with that of their host B. tabaci. Secondary endosymbionts in B. tabaci complex could be divided into three clades based on the 16S rDNA sequences, and horizontal transmission and/or multiple infections might have occurred in these secondary endosymbionts. The distribution of the endosymbionts in B. tabaci biotypes was different, and some peculiar primary and secondary endosymbionts were found in B. tabaci Biotype B. Wolbachia, Candidatus Fritschea bemisiae and Cytophaga-like-organism were not found or scarcely found in B. tabaci Biotype B. Finally the biological implications of different endosymbionts for B. tabaci and future research directions are discussed.