Identification Of Bacillus Of WJ-1 And Study On The Control Of Rice Sheath Blight And Sclerotinia Stem Rot By Bacillus Strain WJ-1

WJ-1 strain is from our lab. In this study, Bacillus strain WJ-1 was identified as Bacillus subtilis with 16S rDNA sequence analysis and its characterization of morphological and physiological and biochemical features.Bacillus strain WJ-1 is able to inhibit mycelial growth of Gibberella zeae、Alternaria alternat、Sclerotinia sclerotiorum、Botrytis cinerea、Fusarium oxysporum、Colletotrichum gossypii、Fusarium solani and other pathogenic fungi. Cultural filtrates of Bacillus subtilis WJ-1 efficiently inhibited mycelial growth of Fusarium solani and Sclerotinia sclerotiorum, which is able to lead to hyphae monstrous growth, and internal material leaked. Fermentation Solution and cultural filtrates of Bacillus subtilis WJ-1 could inhibit germinated sclerotia of Sclerotinia sclerotiorum with the efficacy of 100%.Bacillus strain WJ-1 could excellent control to rice sheat blight effeciently. In vitro trial of control effect showed that by the use of Bacillus strain WJ-1 on time could control Fusarium solani effectiveiy by infecting primary hyphae of Fusarium solani. Control effect in vivo trial proved that Bacillus strain WJ-1 in all treatment have not significant difference with Amy and Jinggangmycin. In field trials, control effects of cell suspension of Bacillus strain WJ-1 were 70.88% and 84.80%. And no significant difference with Amy and Jinggangmycin in control effect. Control effect in vitro trial of Sclerotinia sclerotiorum showed that cultural filtrates of Bacillus subtilis WJ-1 have best control effect, which is more than 50%.The cultural filtrates of Bacillus subtilis WJ-1 were autoclaved at 121℃for 20min, but it could also inhibit mycelial growth of Sclerotinia sclerotiorum. It indicates that there are some antimicrobial substance that has a high thermal stability. The cultural filtrates of Bacillus subtilis WJ-1 have bacteriostasis activity with ammonium sulfate precipitation and protease K, which proved that antimicrobial substance except protein for Antibacterial substanceThis results laid a solid foundation for using Bacillus subtilis WJ-1 against rice sheath blight in the future.