Analysis of the structure of bacterial and fungal communities in disease suppressive and disease conducive tobacco-planting soils in China

To clarify the differences between microbial communities resident in disease suppressive soil (DSS) and disease conducive soil (DCS) in tobacco cultivation, representative soil samples were collected from tobacco plantations in Shengjiaba, China, and the structure and diversity of the resident bacterial and fungal communities were analysed using high-throughput sequencing technology. Our results showed a greater number of operational taxonomic units associated with bacteria and fungi in DSS than in DCS. At the phylum level, abundances of Chloroflexi, Saccharibacteria, Firmicutes, and Planctomycetes in DSS were lower than in DCS, but abundance of Gemmatimonadetes was significantly higher. Abundances of Zygomycota and Chytridiomycota were higher in DSS than DCS, but abundance of Rozellomycota was significantly lower. At the genus level, abundances of 18 bacterial and nine fungal genera varied significantly between DSS and DCS. Relative abundances of Acidothermus, Microbacterium, Curtobacterium, and Colletotrichum were higher in DCS than DSS. The Shannon and Chao1 indices of DSS microbial communities were higher than those of DCS communities. High microbial diversity reduces the incidence of soil-borne diseases in tobacco plantations and promotes the formation of DSSs.