Analysis of microbial diversity in inter-root soil of healthy, diseased and applied biocontrol solution X216 oilseed rape

Rhizoctonia is a devastating soil-borne disease caused by the infection of Rhizoctonia brassicae (Plasmodiophora brassicae), mainly affecting cruciferous plants. Soil microbial diversity is an essential indicator of soil quality. To investigate the effect of soil microbial diversity on Rhizoctonia brassicae infection in Brassica napus, this paper measured the physicochemical properties. It analyzed the high throughput sequencing of soil bacteria and fungi in the inter-root soils of Brassica napus under different treatment conditions. Proteobacteria, Chloroflexi, Rozellomycota, and Basidiomycota were critical species in the development of Rhizoctonia. Principal coordinate analysis showed that soil microbial structure varied greatly in the bacterial community, and there was no significant difference in soil structure in the fungal community. The occurrence of Rhizoctonia affected the inter-root soil microbial community composition structure, resulting in a decrease in soil community diversity. At the same time, the application of biocontrol fungus X216 increased soil microbial diversity. It effectively reduced the occurrence of Rhizoctonia, and this paper provides a basis for the study of microbial diversity in Brassica juncea crops.