Abstract: The coating plate method and plate confrontation method were used to isolate and screen the antagonistic fungi against soil-borne pathogens (Fusarium solani and Sclerotium rolfsii) from the rhizosphere soil of healthy Siraitia grosvenorii.The antagonistic fungi were identified according to their morphological and molecular biology characteristics. Mycelium growth rate method was employed to evaluate the antifungal activity of metabolites from antagonistic fungi.The purpose is to provide a scientific basis for the green control of soil-borne diseases of Siraitia grosvenorii.The results showed that a total of 25 fungi were isolated and 4 antagonistic fungi were screened out.The inhibitory rates of the four antagonistic fungi against Fusarium solani and Sclerotium rolfsii were 42.01%—63.56% and 59.81%—74.17%, respectively.The four antagonistic fungi were identified by morphological observation and molecular biology technique as Trichoderma asperellum,Aspergillus aculeatus,Talaromyces angelicus and Penicillium janthinellum, respectively.Under liquid fermentation conditions, the ethyl acetate extracts from Trichoderma asperellum,Aspergillus aculeatus and Talaromyces angelicus metabolites showed obvious antimicrobial activity against Fusarium solani,with EC₅₀ values of 1.290 1,2.637 0,3.646 9 mg/ mL,respectively.The ethyl acetate extracts from the fermentation products of Aspergillus aculeatus,Talaromyces angelicus and Penicillium janthinellum showed good antimicrobial activity against Sclerotium rolfsii with EC₅₀ values of 1.740 4,3.925 1,0.636 2 mg/mL,respectively.Under the conditions of solid rice fermentation, the fermentation product of Trichoderma asperellum had good antimicrobial activity against Fusarium solani and Sclerotium rolfsii,with EC₅₀ values of 2.339 4 mg/ mL and 1.941 8 mg/ mL.It is suggested that the 4 antagonistic fungi have potential application value for the control of soil-borne diseases of Siraitia grosvenorii.

Key words: Siraitia grosvenorii, Soil-borne disease, Antagonistic fungi, Fermentation product;Antimicrobial activity

摘要： 采用涂布平板法和平板对峙法从发病罗汉果果园健康植株根区土壤中分离、筛选对罗汉果土传病菌（根腐病菌和白绢病菌）有抑制作用的拮抗真菌，结合形态学和分子生物学特征对其进行鉴定，并采用菌丝生长速率法测定拮抗菌发酵产物的抗菌活性，旨在为罗汉果土传病害的绿色防控提供科学依据。结果表明，共分离出25 株真菌并从中筛选出4 株拮抗真菌，对根腐病菌、白绢病菌的抑菌率分别为42.01%~63.56%、59.81%~74.17%，通过形态学观察和分子生物学技术鉴定4株拮抗真菌分别为棘孢木霉（Trichoderma asperellum）、棘孢曲霉（Aspergillus aculeatus）、篮状菌（Talaromyces angelicus）和微紫青霉（Penicillium janthinellum）。在液体发酵条件下，棘孢木霉、棘孢曲霉、篮状菌发酵产物的乙酸乙酯萃取物均对罗汉果根腐病菌表现出明显的抑菌活性，EC₅₀值分别为1.290 1、2.637 0、3.646 9 mg/mL；棘孢曲霉、篮状菌、微紫青霉发酵产物的乙酸乙酯萃取物对白绢病菌表现出较好的抑菌活性，EC₅₀值分别为1.740 4、3.925 1、0.636 2 mg/mL。大米固体发酵条件下，棘孢木霉发酵产物对根腐病菌、白绢病菌均有较好的抑菌活性，EC₅₀值分别为2.339 4、1.941 8 mg/mL。可见，4种拮抗真菌在罗汉果土传真菌病害防治上具有潜在的开发应用价值。

关键词: 罗汉果, 土传病害, 拮抗真菌, 发酵产物, 抑菌活性