贝莱斯芽胞杆菌S297对生菜菌核病的防治效果

Control Effect of Bacillus velezensis S297 on Lettuce Sclerotinia

生菜菌核病是由核盘菌Sclerotinia sclerotiorum引起的一种植物病害,主要危害生菜的茎基部。本研究以前期分离获得的贝莱斯芽胞杆菌Bacillus velezensis S297为研究对象,研究其对生菜菌核病的生防作用。结果显示,贝莱斯芽胞杆菌S297能抑制核盘菌菌丝的生长、菌核的生成和萌发。以5×10^(7)cfu/mL浓度S297发酵液处理核盘菌侵染离体生菜叶片36h后的防效达84.65%;贝莱斯芽胞杆菌S297与木霉菌协同使用,防效提高至97.52%,与50%啶酰菌胺1mg/mL处理的防效无显著差异。田间试验中,贝莱斯芽胞杆菌S297发酵液(5×10^(7)cfu/mL)防效为81.08%,与木霉菌协同使用防效为85.14%,与50%啶酰菌胺1 mg/mL处理无显著差异。贝莱斯芽胞杆菌S297对核盘菌的作用结果表明,菌株S297可使核盘菌菌丝变形,抑制核盘菌果胶甲基半乳糖醛酸酶(PMG)、多聚半乳糖醛酸酶(PG)和纤维素酶(CL)的酶活性,亦抑制核盘菌在侵染生菜过程中草酸的产生。

Lettuce sclerotinia is a plant disease caused by Sclerotinia sclerotiorum,which mainly affects the stem base of lettuce.In this study,Bacillus velezensis S297 isolated from the previous stage was taken as the research object to investigate its biological control effect on lettuce sclerotinia.The results showed that S297 inhibited the growth of S.sclerotiorum,the formation of sclerotia and germination of sclerotia.The effect of S297 fermentation broth at 5×10^(7) cfu/mL on isolated lettuce leaves infected with S.sclerotiorum reached 84.65%after 36 h treatment.When Bacillus velezensis S297 was mixed with Trichoderma,the control effect was increased to 97.52%,and there was no significant difference between the control effect of 50%Boscalid at 1 mg/mL.In the field experiment,the control efficiency of Bacillus velezensis S297 fermentation broth(5×10^(7) cfu/mL)was 81.08%.The control effect of the combined treatment group of Bacillus velezensis S297 and Trichoderma was 85.14%,and there was no significant difference in the control effect compared to 50%Boscalid at 1 mg/mL.Bacillus velezensis S297 deformed the mycelium of lettuce sclerotinia,and inhibited the activities of polymethylgalacturonases(PMG),polygalacturonases(PG)and cellulose(CL)of Sclerotinia sclerotiorum.Bacillus velezensis S297 also significantly inhibited the production of oxalic acid during the infection of lettuce.