油茶抗性无性系茶皂素含量对茶籽象幼虫肠道菌群结构的影响

Effects of Saponin Content in Camellia oleifera Resistant Clones on the Gut Microbiome Structure of the Seed Pest Curculio chinensis(Coleoptera:Curculionidae)

【目的】明确基于茶皂素含量差异的油茶抗性无性系是否影响茶籽象存活量和肠道菌群结构;进一步明确茶皂素在抗茶籽象方面的作用,为油茶抗虫品种选育工作以及开发新的茶籽象绿色防控技术提供理论依据。【方法】通过将茶籽象回接于茶皂素存在含量差异的5个油茶无性系,待幼虫发育成熟后,测定不同无性系上幼虫存活量,并与茶果茶皂素含量进行相关性分析;通过16S rRNA扩增子测序,比较分析油茶无性系对茶籽象肠道菌群物种组成、Alpha多样性、Beta多样性以及标志物种的影响。【结果】茶籽象存活量与茶果果仁内茶皂素含量的相关性为y=0.2525x^(2)–10.096x+107.47(R^(2)=0.7189),茶籽象存活数随着茶皂素含量上升而下降;对茶籽象肠道菌群结构分析发现,长林166和长林40号这2种高含量茶皂素无性系中茶籽象肠道菌群Alpha多样性、Beta多样性均与长林55号、53号、3号茶籽象肠道样本存在显著差异(P<0.05);有51个差异OTUs在高含量茶皂素组的茶籽象肠道内显著富集,分别属于黄杆菌属、固氮螺菌属、阪岐肠杆菌属、假单胞杆菌属、不动杆菌属,其中假单胞杆菌属、不动杆菌属占比最高。【结论】高含量茶皂素的无性系可以明显影响茶籽象存活量、茶籽象肠道菌群多样性及组成结构差异;油茶茶皂素含量可以作为油茶抗虫品种选育的重要化学指标。

【Objective】The aims of this study are to determine whether the content of tea saponin among Camellia oleifera resistant clones affect the composition of C.sinensis’gut microbiota,and their survival rates,and further to clarify the role of tea saponin on C.sinensis resistance,so as to provide theoretical support for the selection and breeding of C.sinensis resistant varieties and the development of new green prevention and control techniques against C.chinensis.【Method】C.chinensis was inoculated into five C.oleifera clones with different content of tea saponin.After larvae matured,the survival of larvae on different clones was calculated and the correlation between the larvae survival rate and the content of tea saponin was analyzed.Sequence obtained from 16S rRNA region was used to compare and evaluate the effects of C.oleifera clones on taxonomic composition,alpha diversity,beta diversity and marker species of gut microbiota.【Result】The correlative regression analysis showed that the correlation between the survival of C.chinensis and the content of tea saponin was y=0.2525 x^(2)-10.096 x+107.47(R^(2)=0.7189).The survived number of C.chinensis decreased with the increase of tea saponin content.Through the analysis of the gut microbiota structure of C.chinensis,it was found that alpha and beta diversities of C.chinensis gut microbiota in Changlin 166,and 40 clones with higher content of tea saponin were significantly different from those in Changlin 55,53 and 3 clones(P<0.05).The result of marker species analysis showed that 51 differential OTUs were significantly enriched in the gut of C.chinensis with higher tea saponin group,residing in the genera of Flavobacterium,Azospirillum,Crolobacter,Pseudomonas and Acintobacter,and the last two genera accounted for the highest proportion.【Conclusion】Colones with high content of tea saponin can significantly affect survival of C.chinensis,its gut microbiota diversity,and microbial composition.The tea saponin content can be considered as an important chemical index for the breeding of insect resistant varieties for C.oleifera.