Abstract: This work is to select an antagonistic strain against Fusarium moniliforme in rice from the rhizosphere soil of rice,and study its primary inhibitory effect on plant pathogens and biocontrol effect. The strain was separated from the rhizosphere soil of rice by the plate dilution method,using the F. moniliforme as the indicator strain for the antagonistic strain being screened by plate confrontation method. It was identified based on morphological,physiological and biochemical characteristics and 16S rDNA phylogenetic analysis. The effects of the sterile fermented liquor of the strain on the hypha growth of F. moniliforme were analyzed,and its antagonistic spectrum was measured,also pot experiment was conducted. Six strains were isolated,and one SH15 presented highly antagonistic effect on F. moniliforme,and was identified as Paenibacillus polymyxa. Sterile fermented liquor of strain SH15 showed significant inhibitory effect on hypha growth of F. moniliforme. Strain SH15 had broad antimicrobial spectrum,antibacterial activity on F. moniliforme,Fusarium proliferatum,Fusarium oxysporum,Phytophthora capsici,Phytopthora infestans,and Alternaria cucumerina. Rice pot experiments revealed that inoculation of the P. polymyxa SH15 significantly reduced the disease index of Fusarium moniliforme in rice with the average efficiency 65.68%. Therefore,there is certain application value for P. polymyxa SH15 in biological control of rice bakanae disease.

Key words: Fusarium moniliforme, Paenibacillus polymyxa sterile, fermented liquid, antagonistic spectrum