Composition analysis of beneficial microorganisms in disease-suppressive soils against tobacco bacterial wilt

In order to explore the beneficial microbial resources for disease-suppressive soils against tobacco bacterial wilt, field experiments were conducted to analyze the microbial community structure and the relative abundances of Ralstonia solanacearum and antagonistic bacteria in disease-suppressive soils and disease-conducive soils at different altitudes. The results showed that at phylum level, the relative abundances of beneficial bacteria (Actinobacteria, Firmicutes, Cyanobacteria) and beneficial fungi (Zygomycota, Chytridiomycota) in disease-suppressive soils were higher than those in disease-conducive soils. At genus level, the relative abundances of some beneficial microorganisms (Mesorhizobium, Nitrosospira) and antagonistic microorganisms (Pseudomonas, Flavobacterium, Rhizobium, Aspergillus, Trichoderma, Myrothecium) in disease-suppressive soils were significantly higher than those in disease-conducive soils, which all had obviously negative correlations with the incidence of bacterial wilt. However, the relative abundance of pathogenic microorganism (Ralstonia) in disease-suppressive soils was significantly lower than that in disease-conducive soils. To sum up, there were abundant antagonistic microorganisms in disease-suppressive soils against tobacco bacterial wilt.