Effects of control agents against tobacco root-knot nematode disease on bacterial community structure in rhizosphere soil of tobacco plants

In order to explore the effects of different control agents against tobacco root-knot nematode disease on the bacterial community structure in the rhizosphere soil of tobacco plants, the Illumina MiSeq high-throughput sequencing technology was used to detect the changes of the bacterial community structure in the rhizosphere soil of tobacco plants after treated with abamectin, Bacillus subtilis, Paecilomyces lilacinus, Pseudomonas fluorescens, Trichoderma harzianum, and abamectin+carbofuran. The results showed that compared with the control group (CK), the chemical agents significantly reduced the species richness and diversity of the bacterial community, as well as the stability of the community structure. Biocontrol agents significantly increased the species richness and diversity of the bacterial community. At phylum level, Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria were shared dominant bacteria phyla with the average relative abundances of 35.13%, 23.12%, 13.84%, 8.97% respectively. At genus level, Sphingomonas and Gemmatimonas were shared dominant bacterial genera with the average relative abundances of 5.67% and 3.29% respectively. The relative abundances of Pseudarthrobacter, Massilia, Streptomyces, and Blastococcus were significantly different after treatment. Therefore, the biocontrol agents can increase the species richness and diversity of the bacterial community in the rhizosphere soil, regulate the community structure, raise the relative abundance of beneficial bacteria, and improve the soil ecological environment.