2种不同寄主对桉树枝瘿姬小蜂体内细菌多样性的影响

Effects of two different hosts on the bacterial diversity in Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae: Tetrastichinae)

【目的】桉树枝瘿姬小蜂是一种林业的重要入侵害虫,为了探明桉树枝瘿姬小蜂的寄主适应机制,研究2种不同寄主植物对桉树枝瘿姬小蜂体内细菌群落组成及多样性的影响。【方法】以分别取食巨园桉DH 201-2和窿缘桉的桉树枝瘿姬小蜂雌性成虫为材料,采用Illumina Hi Seq高通量测序技术对桉树枝瘿姬小蜂体内细菌16S r DNA基因的V3+V4区进行测序分析。【结果】取食2种寄主植物的桉树枝瘿姬小蜂体内细菌16S r DNA基因序列文库共得到273461条有效序列,在97%相似度聚类分析得到230个细菌OTUs,其中取食巨园桉DH201-2的雌成虫体内鉴定出206个OTUs,取食窿缘桉的雌成虫体内鉴定出171个OTUs。取食巨园桉DH201-2的雌成虫体内细菌的种类更多,细菌群落丰富度更高,但多样性较低;取食窿缘桉的雌成虫体内细菌种类较少,细菌群落丰富度更低,多样性更高。取食2种寄主植物的桉树枝瘿姬小蜂雌成虫体内细菌共注释得到14门24纲41目73科123属,有83个注释到了种;两者体内细菌的优势菌门均为变形菌门,相对丰度均大于90%。取食巨园桉DH201-2的雌成虫体内细菌的优势菌属为立克次氏体属,相对丰度高达93.11%,物种多样性较低;取食窿缘桉的雌成虫体内细菌的优势属为立克次氏体属,其相对丰度为73.61%,物种多样性较高。【结论】取食2种不同寄主植物的桉树枝瘿姬小蜂体内细菌群落丰富度和多样性有明显差异,说明寄主植物能够影响害虫体内细菌的组成与结构。

【Aim】 Leptocybe invasa is an important invasive forestry pest. We examined the host adaptation mechanism of L. invasa by studying the influence of different hosts on its bacterial community composition and diversity. 【Method】 Illumina HiSeq high-throughput sequencing was used to analyze the V3+V4 region of bacterial 16 S rDNA from L. invasa adult females, which were fed on DH201-2(Eucalyptus grandis×E. tereticornis) and E. exserta. 【Result】 A total of 273461 valid reads were obtained from the 16 S rDNA sequence library of the two samples, and 230 bacterial operational taxonomic units were identified using a 97% similarity clustering analysis, of which 206 were identified from DH201-2 and 171 from E. exserta. Adult females fed on DH201-2 had more bacterial species and higher bacterial community richness but lower diversity. Female adults of L. invasa fed on E. exserta had fewer bacterial species and lower bacterial community richness but higher diversity. Fourteen phyla, 24 classes, 41 orders, 73 families, 123 genera, were identified among the bacteria in the two samples. The dominant bacterial phylum in both populations was Proteobacteria, with a relative abundance of >90%. The dominant bacterial genus in L. invasa feeding on DH201-2 was Rickettsia, accounting for 93.11%, reflecting low diversity, and the relative abundance of Rickettsia in individuals feeding on E. exserta was 73.61%, showing higher species diversity. 【Conclusion】 The richness and diversity of bacterial communities significantly differed in L. invasa fed on different host plants, suggesting that host plants can affect the composition and structure of bacteria in the larvae of L. invasa.