淡紫褐链霉菌NBF715防控黄瓜猝倒病及其机制的初步研究

Control effect of Streptomyces enissocaesilis NBF715 on damping-off of cucumber and its preliminary antifungal mechanism

为明确淡紫褐链霉菌NBF715对黄瓜猝倒病的防控效果和抑菌机制,对其进行了对峙培养、抑菌活性、抑菌物质测定和盆栽防效测定。结果表明,对峙培养条件下NBF715对瓜果腐霉抑菌率为55.6%,无菌发酵液稀释10、25、50倍和100倍对瓜果腐霉抑菌率分别为84.1%、69.2%、47.8%和36.5%。光学显微镜和扫描电镜下观察,与对照相比,NBF715处理后瓜果腐霉菌丝发生扭曲、肿胀变形和消解。NBF715菌株能产生淀粉酶、纤维素酶、β-1,3-葡聚糖酶和嗜铁素。发酵液原液和稀释5倍发酵液浸种处理,对黄瓜猝倒病防效分别为97.1%和80.2%。NBF715菌株具有较好的生防应用前景。

In order to clarify the control effect of Streptomyces enissocaesilis strain NBF715 against damping-off of cucumber and its antifungal mechanism,the confrontation culture,antibacterial activity,determination of antibacterial substances and pot control effect were carried out.The results showed that the inhibition rate was 55.6%against Pythium aphanidermatum in the confrontation culture.The inhibition rates of 10,25,50 or 100 times dilution of NBF715 fermentation filtrate against P.aphanidermatum were 84.1%,69.2%,47.8%and 36.5%,respectively.Observed under the optical microscope and scanning electron microscope,NBF715 caused the mycelium to distort,enlarge and digestion.The strain could produce amylase,cellulase,β-1,3-glucanase and siderophore.The control effects were 97.1%and 80.2%on damping-off of cucumber,respectively,by treating seeds with original or five times diluted fermentation filtrate.NBF715 strain has a good prospect for biocontrol application.