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【目的】研究外源过氧化氢(H2O2)处理对采后马铃薯块茎干腐病的控制效果及作用机理。【方法】在离体条件下通过扫描电镜、透射电镜等方法观察分析外源H2O2对马铃薯干腐病菌(Fusarium sulphureum)生长、菌落形态及其超微结构的影响,并以陇薯3号马铃薯为试材,分别在处理前后接种F.sulphureum,研究外源H2O2对病害的治愈和预防作用。【结果】外源H2O2处理强烈抑制了F.sulphureum的菌丝生长和孢子萌发且表现出明显的浓度效应,显著增大了F.sulphureum的细胞膜透性;扫描电镜观察发现H2O2处理过的F.sulphureum菌落分布不均匀,菌丝缠绕、扭曲在一起,部分菌丝出现断裂、塌陷等现象;透射电镜进一步观察到H2O2处理过的菌丝细胞壁加厚且内部出现空腔。体内试验结果表明,外源H2O2处理对处理前后接种F.sulphureum的马铃薯块茎干腐病均具有一定控制作用。【结论】H2O2不仅对病原物具有直接的抑制作用,还能有效提高马铃薯块茎组织的抗病性,因此H2O2可以作为一种具有潜力的天然防腐剂应用于马铃薯采后病害的控制。
【Objective】 The purpose of this study was to investigate the control effect and mechanism of exogenous hydrogen peroxide (H2O2) on postharvest potato tuber rot disease. 【Method】 The effects of exogenous H2O2 on growth, colony morphology and ultrastructure of Fusarium sulphureum were observed under scanning electron microscopy and transmission electron microscopy. The effects of exogenous H2O2 The test materials were inoculated with F.sulphureum before and after treatment to study the effect of exogenous H2O2 on the cure and prevention of the disease. 【Result】 Exogenous H2O2 strongly inhibited the mycelial growth and spore germination of F.sulphureum and showed a significant concentration effect, which significantly increased the membrane permeability of F.sulphureum. The H2O2-treated F was observed by scanning electron microscopy. The results showed that the mycelia were entangled and twisted together with some hyphae breaking and collapsing. Transmission electron microscopy (TEM) revealed that the hyphal cell walls of H2O2-treated mycelium were thickened and cavities appeared inside. In vivo experiments showed that exogenous H2O2 treatment had certain control effects on the dry rot of potato tubers inoculated with F.sulphureum before and after treatment. 【Conclusion】 H2O2 not only has a direct inhibitory effect on pathogens, but also can effectively improve the disease resistance of potato tubers. Therefore, H2O2 can be used as a potential natural preservative in the control of postharvest diseases of potato.