苹果绵蚜体内共生细菌组成及高温对其多样性的影响

Composition of Symbiotic Bacteria in Eriosoma lanigerum(Hemiptera:Pemphigidae)and Effects of High Temperature on Their Diversity

苹果绵蚜是苹果园中的重要害虫,高温不利于其发生为害,为明确苹果绵蚜体内共生细菌的物种组成及共生细菌是否介导高温影响苹果绵蚜适合度,本研究利用Illumina MiSeq测序平台测定苹果绵蚜体内共生细菌的16S rDNA序列,并分析物种组成及高温对共生细菌多样性和相对丰度的影响。通过测序共获得823 258条高质量序列,5 139个OTUs,变形菌门(Proteobacteria)为优势菌门,γ-变形菌纲(Gammaproteobacteria)、拟杆菌纲(Bacteroidia)和α-变形菌纲(Alphaproteobacteria)为优势菌纲,拟杆菌目(Bacteroidales)、β-变形杆菌目(Betaproteobacteriales)和肠杆菌目(Enterobacteriales)为优势菌目;若蚜的共生细菌各龄期高度相似,与成蚜有较大差异,其中成蚜中的果胶杆菌属(Pectobacterium,29.76%)和苍白杆菌属(Ochrobactrum,13.68%)相对丰度高于若蚜,而栖热菌属(Thermus,2.72%)和贪铜菌属(Cupriavidus,1.42%)相对丰度低于若蚜;在高温下苹果绵蚜体内共生细菌多样性显著降低,同时,具杀虫作用的假单胞菌属(Pseudomonas)相对丰度随温度升高逐渐升高,有利于宿主取食的果胶杆菌属和维持存活的不动杆菌属(Acinetobacter)相对丰度随温度升高逐渐降低,推测以上3种共生细菌的变化是高温降低苹果绵蚜适合度的关键。本研究明确了苹果绵蚜体内共生细菌的物种组成及高温对共生细菌的影响,可为研究共生细菌与宿主间互作,解析高温降低苹果绵蚜适合度机制奠定理论基础。

Eriosoma lanigerum is an important pest in apple orchards,and high temperature is unfavor-able for its occurrence.To clarify the composition of symbiotic bacteria in E.lanigerum and whether the symbiotic bacteria mediating the effect of high temperature on the fitness of E.lanigerum,the Illumina MiSeq sequencing platform was used to determine the 16S rDNA sequences of the symbiotic bacteria in E.lanigerum,and the species composition and the effects of high temperature on diversity and relative abundance of symbiotic bacteria were analyzed.Through sequencing,a total of 823258 high-quality sequences and 5139 OTUs were obtained.The Proteobacteria was the dominant phylum with the Gammaproteobacteria,Bacteroidia and Alphaproteobacteria being dominant classes,and the Bacteroidales,Betaproteobacteriales and Enterobacteriales being dominant orders.The symbiotic bacteria of the nymphs were highly similar among instars,showing significant differences from those of the adults.Specifically,the relative abundance of Pectobacterium(29.76%)and Ochrobactrum(13.68%)in adults was higher than that in nymphs,while that of Thermus(2.72%)and Cupriavidus(1.42%)was lower than that in nymphs.Under high temperature,the diversity of symbiotic bacteria within E.lanigerum bodies significantly decreased.Concurrently,the relative abundance of the entomopathogenic Pseudomonas genus gradually increased with temperature rising.In contrast,the relative abundance of the Pectobacterium genus,which was advantageous for host’s feeding,and the Acinetobacter genus,which was crucial for survival,gradually decreased with temperature increasing.It was speculated that the changes of the above three species of symbiotic bacteria should be key to the reduction in fitness of E.lanigerum under high temperature.This study clarified the species composition of symbiotic bacteria in E.lanigerum and the effect of high temperature on them,which would provide a theoretical basis for the interaction between symbiotic bacteria and hosts,and lay the theoretic foundation for elucidating the mechanism of high temperature reducing the fitness of E.lanigerum.