草莓根腐病菌C16-4的分离鉴定及生物学特性研究

Studies on isolation,identification and biological characteristics of pathogenic fungus strain C16-4 of strawberry root rot

【目的】针对近年来设施草莓根腐病普遍发生并逐年加重的现状，明确北京地区引起设施草莓根腐病的主要致病真菌的种类。【方法】以草莓根腐病（Strawberry root rot）为研究对象，采用组织分离法，从病株上共分离纯化得到5个菌株，对主要致病菌C16—4进行了鉴定和生物学特性研究。【结果】结果表明，最利于C16—4生长和产孢的培养基为PDA：最佳氮源为蛋白胨．最佳碳源为麦芽糖和淀粉。菌丝在10—35℃均可以生长，在本试验所设温度范围内，最适生长和产孢的温度分别为25℃和30℃。菌丝在pH值为5～7时均可以生长，最适pH值为7，中性条件下利于产孢。不同光照条件对菌丝生长影响不明显，在全黑暗情况下产孢量最大。【结论】通过培养性状、形态特征、致病性测定结果和ITS序列分析，将C16—4鉴定为尖孢镰刀菌（Fusarium oxysporium Schlecht）。

[Objective] In recent years, strawberry root rot occurs seriously in greenhouse of different re- gions. [Methods] Five pathogenic fungus strains from diseased root were isolated and C 16-4 was identi- fied and studied. [Results] Biological trait test showed that the optimal condition for C16-4 growth and sporulation was PDA medium with tryptone, maltose and starch as nitrogen and carbon source. Mycelium could grow between 10℃ and 35℃, and the optimal temperature for growth and sporulation was 25 and 30℃ respectively. Mycelium could grow between pH 5 to 7, but the optimal was pH 7. More spores could be produced under neutral conditions. Different light conditions had obvious effect on mycelium growth, and the most spores could be produced under full dark condition. [Conclusion] Via morphology, pathogenic assay and ITS sequenc analysis, C16-4 strain was finally identified as Fusarium oxysporium Schleeht.