伽师甜瓜猝倒病生防放线菌的筛选

Screening of antagonistic actinomycetes against 'Jiashi' Cucumis melo L. damping-off

【目的】分离、鉴定引起伽师甜瓜(Cucumismelo L.)猝倒病的病原菌,筛选可用于甜瓜猝倒病生物防治的拮抗性放线菌。【方法】采用组织分离法分离伽师甜瓜猝倒病的病原菌,用琼脂块法和无菌发酵滤液抑菌性试验筛选拮抗瓜果腐霉的生防放线菌,搭片法观察生防放线菌菌丝与瓜果腐霉菌丝间的相互作用。【结果】伽师甜瓜猝倒病的病原菌为瓜果腐霉(Pythium aphanidermatum);筛选出7株对瓜果腐霉具有显著拮抗性的生防放线菌,其中8号放线菌对瓜果腐霉的拮抗环宽度为13.3mm,其无菌发酵滤液对瓜果腐霉的抑菌率在培养120h时高达88.3%。【结论】7株生防放线菌对由瓜果腐霉引起的伽师甜瓜猝倒病均有显著抑制作用;7株生防菌可通过产生抗菌物质或缠绕、消解菌丝的方式抑制瓜果腐霉生长。

[Objective] This study was to isolate and identify the pathogen causing Cucumis melo L. damping-off,as well as screen antagonistic actinomycetes of Pythium aphanidermatum. [Method] Tissueisolating method was used to isolate the pathogen, antagonistic actinomycetes of Pythium aphanidermatum was screened through both agar block method and axenic fermentation extract experiment, and the method of building pieces on plate was adopted in observing the mutual effects between antimicrobial actinomycetes and Pythium aphanidermatum. [Result] The phytopathogenic fungus Pythium aphanidermaturn was isolated;7 strains of antagonistic actinomycete, which had obvious inhibitory effects on Pythium aphanidermature were screened. The inhibitory ring of No. 8 strain was 13.3 ram,and reached 88.3% when cultivated for 120 h. [Conclusion] 7 antimicrobial strains had strong inhibitory effects on the growth of Pythium aphanidermatum ,which caused ‘Jiashi＇ Cucumis melo L. damping-off, by producing antibiotic and mutual effect between mycelia,such as winding and decomposition.