关键词: 龟纹瓢虫, 共生微生物, 高通量测序, 优势菌群

Abstract: 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 16S rDNA 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.

Key words: Propylea japonica, symbiotic bacteria, Illumina MiSeq techniques, advantage flora