Fecha de publicación: 25/01/2022 Fuente: Wipo Tobacco Agriculture The invention relates to a bacterium. The bacterium is Bacillus velezensis WY2. The preservation place is Institute of Microbiology, Chinese Academy of Sciences, Dadn Road, Chaoyang District, Beijing, and the preservation number is CGMCC No.6662. According to the bacillus velezensis WY2 disclosed by the invention, the effective control on the tobacco root rot can be realized, and the relative control effect is over 60 percent; and the bacterium also has a very good bacteriostatic effect on phytophthora parasitica, botrytis cinerea, sclerotinia sclerotiorum, target leaf pathogen, mildew pathogen, alternaria alternata and the like. The bacterium is good in prevention and treatment effect and has high application and popularization value.