Abstract:To investigate the inhibitory effect of biocontrol agent against Magnaporthe oryzae, 3 biocontrol fungi which have obvious antifungal effect were screened out from rhizosphere of Ginseng with plate-screening method.The strain GS-1, which exhibited the best antifungal performance, was identified as Bacillus velezensis based on physiological and biochemical characteristics, as well as 16S rDNA sequence analysis. The antifungal spectrum showed that biocontrol bacterium GS-1 demonstrated a degree of inhibitory activity against M. oryzae, Fusarium graminearum, Rhizoctonia solani, Setosphaeria turcica, Sclerotinias sclerotiorum and Botrytis cinerea, respectively. The inhibitory rate of GS-1 fermentation broth and n-butyl alcohol extract to M. oryzae was 90% and 57%, respectively.The conductivity and MDA content of M. oryzae was significantly increased under GS-1 treatment, so GS-1 would be a potential biocontrol strain against rice blast, which laid a basis for the development of a microbial agent to control rice blast disease in future studies.