龟纹瓢虫幼虫体内主要共生菌种类分析

Analysis of Symbiotic Bacteria of Propylea japonica Larvae

共生菌和昆虫是互利共生的关系,它参与宿主生殖、代谢、解毒等生理过程。龟纹瓢虫为农田生态系统重要天敌昆虫,同时具有取食植物花粉的习性。为明确龟纹瓢虫体内共生菌的种类与群落结构,通过Illumina MiSeq平台对龟纹瓢虫幼虫体内共生菌的16S r DNA V3~V4区进行高通量测序,生物信息学方法分析共生菌的种类和多样性。结果显示,共获得3910个OTUs,长度为360~480 bp的序列占99.54%;OTU注释结果表明,龟纹瓢虫共生菌包括37个门,75个纲,143个目,261个科,605个属;变形菌门Proteobacteria(51.84%)、厚壁菌门Firmicutes(21.81%)、放线菌门Actinobacteria(11.35%)、蓝藻菌门Cyanobacteria(7.06%)、拟杆菌门Bacteroidetes(4.49%)为龟纹瓢虫幼虫的5个优势种群。在属水平上葡萄球菌Staphylococcus(16%)、不动杆菌属Acinetobacter(8.54%)、Paracocccus(4.93%)、假单胞菌Pseudomonas(3.59%)、Boechera gunnisoniana(3.34%)、棒状杆菌属Corynebacterium(2.18%)、阪崎肠杆菌Cronobacter(2.04%)、考克氏菌属Kocuria(1.50%)、链球菌属Streptococcus(1.15%)和芽胞杆菌Bacillus(1.11%)为优势菌群。本研究初步明确了龟纹瓢虫幼虫体内共生菌种群组成与结构,为通过共生菌提高龟纹瓢虫人工繁殖效率提供参考,同时为转基因植物对龟纹瓢虫的安全评价提供新的思路。

Symbiotic relationships between bacteria and insects are common in nature. Symbiotic bacteria participate in host＇s physiological processes of reproduction, metabolism and detoxification. Propylaea Japonica（Coleoptera： Coccinellidae） is an important natural enemy of insect pests in agroecosystems. To clarify the community structure and diversity of bacteria in this insect, the V3―V4 regions of 16 S r DNA genes of bacteria were investigated in the beetle larvae using high-throughput sequencing of Illumina MiSeq techniques and bioinformatics methods. A total of 3910 OTUs were obtained, of which sequences of a length 360―480 bp accounts for 99.5%. The bacteria were identified to 37 phylum, 75 classes, 143 orders, 261 families, and 605 genera. Bacteria species of Proteobacteria（51.84%）, Firmicutes（21.81%）, Actinobacteria（11.35%）, Cyanobacteria（7.06%）, and Bacteroidetes（4.49%） were dominant in P. japonica. On the genus level, Staphylococcus（16%）, Acinetobacter（8.54%）, Paracocccus（4.93%）, Pseudomonas（3.59%）, Boechera gunnisoniana（3.34%）, Corynebacterium（2.18%）, Cronobacter（2.04%）, Kocuria（1.50%）, Streptococcus（1.15%）, and Bacillus（1.11%） were dominant. The preliminarily defined structure and composition of symbiotic bacteria in the P. japonica larvae provide a basis for improving its artificial rearing and a new perspective for the safety evaluation of transgenic plant for P. japonica.