辣椒主要病害广谱生防木霉菌的筛选与评价及鉴定OA

[Objective]The Trichoderma strains with a broad-spectrum biocontrol effect against 4 major diseases of Fusarium oxysporum,Phytophthora capsici,Athelia rolfsii and Colletotrichum capsici in chili pepper were isolated and screened to provide biocontrol resources for sustainable prevention and control of major diseases in chili peppers.[Method]The Trichoderma strains with an optimal antagonistic effect against 4 common diseases were isolated and screened from the rhizosphere soil of chili peppers at different growth stages by the gradient dilution method and plate confrontation method.The inhibition activity of the fermentation liquid of Trichoderma strains was determined by the colony diameter method.Meanwhile,the biocontrol effect was evaluated by the pot and in vitro pepper prevention and control experiments.The screened strains were identified in morphology and molecular biology.[Result]10 Trichoderma strains were isolated from the soil samples.The inhibitory rate of strain YDMM-07 against F.oxysporum,A.rolfsii,P.capsici and C.capsici was 83.71%,81.79%,93.24%and 85.51%respectively.The inhibitory rate of strain YDMM-07 sterile fermentation broth against F.oxysporum,A.rolfsii,P.capsici and C.capsici was 49.63%,31.82%,58.30%and 63.22%,separately.The prevention and control rate of strain YDMM-07 fermentation broth containing mycelia against F.oxysporum,P.capsici and A.rolfsii was 66.98%,71.00%and 62.98%in the pot experiment respectively,and the control rate of the sterile fermentation broth against C.capsici of in vitro pepper reached 52.39%.Strain YDMM-07 was identified as Trichoderma longibrachiatum according to its morphology and molecular biology.[Conclusion]T.longibrachiatum YDMM-07 strain with a good prevention and control effect against 4 major diseases of F.oxysporum,P.capsici,A.rolfsii and C.capsici can be used in development of antibiological agents against diseases in chili pepper.