木薯器官浸提液对香蕉尖孢镰刀菌的抑菌作用

Antifungal Effects of Extracts of the Cassava Organ on Fusarium oxysporum f. sp. cubense in Banana

香蕉枯萎病是一种由尖孢镰刀菌引起的土传病害,枯萎病的发生对香蕉产业造成严重的冲击。本文针对香蕉枯萎病难以防控的难题,采用生长速率法探讨木薯地上地下部器官的乙醇和水浸提液在不同培养时间对香蕉尖孢镰刀菌的抑菌作用,为香蕉枯萎病的防治提供理论依据。结果表明：（1）木薯器官的乙醇和水浸提液对香蕉尖孢镰刀菌的生长均有一定程度的抑菌效果;（2）木薯地下部器官浸提液的抑菌效果显著强于地上部器官;（3）浸提液质量浓度为50mg/L的抑菌效果显著高于清水对照和质量浓度为25mg/L的效果,而浸提液质量浓度为25mg/L和100mg/L的抑菌效果与清水对照无显著差异,即抑菌效果最佳浸提液质量浓度为50-100mg/L;（4）培养时间以24h抑菌率最高,且与72、96、120h培养时间的抑菌率差异显著。而培养时间为48、72、96和120h之间的抑菌率差异不显著,说明24-48h的培养时间抑菌效果最优。据此研究,木薯地下部器官作为防控香蕉枯萎病的植物源农药具有一定的应用前景。

Banana Fusarium wilt disease is caused by Fusarium oxysporum f. sp. cubense （FOC） race 4 and reported to be the most limiting factor in banana production worldwide. The antifungal effects of extracts of cassava organ on FOC population were investigated by growth rate method in this study. The above-ground and underground parts of the cassava organ during the stage of root formation were extracted by ethanol and water respectively. The results showed that the extracts had inhibition to the banana Fusarium oxysporum f. sp. cubense either by ethanol or by water. The antifungal effect of the underground organ was stronger than that of the aboveground. The antifungal effect of the 50 mg/L organ extracts were strongest in the 25 mg/L extracts and water, while the effect of the 25 mg/L and 100 mg/L extracts had no significance, therefore, the effect of 50 - 100 mg/L of the organ extracts were best. The inhibition rate at 24 h incubation time was highest, and had significantly diffidence in the 72 h, 96 h and 120 h.