Variation of Microbial Community in Healthy and Disease-Susceptible Tobacco Soils

Soil microbes are vital for the development of plant growth. Little is known about how the discrepancy of microbes mediate the microbial community structure of healthy (CK) and disease-susceptible soils with black root rot (BR, Thielaviopsisbasicola ) and root-knot nematode (RK, Meloidogyne incognita; M. javanica ) of flue-cured tobacco ( Nicotianatabacum L.). In this study, we analyzed the soil and microbial properties, and showed the differences of soil microbial composition and diversity between soils. Specially, soil was more acid with lower diversity, higher nutrient content with higher abundance of Proteobacteria , Ascomycota , Basidiomycota in the disease-susceptible soils. While, compared with disease-susceptible soils, the protease and urease activities, as well as soil pH, available potassium content, and the relative abundance of beneficial bacterial and fungal genera (including Bacillus , Micromonospora , Lysobacter , Microvirga , Chaetomium and Arthrobotrys ) were higher in CK soils. The variations of soil physiochemical factors and enzyme activities resulted in differences in microbial community structure and composition between healthy and disease-infected flue-cured tobacco soils. Our results bring novel insights to control the disease-susceptible of flue-cured tobacco fields through management of rhizosphere community struture.