香蕉棒孢霉叶斑病病原菌生物学特性测定

[目的]明确香蕉棒孢霉叶斑病病原菌多主棒孢菌[Corynespora cassiicola(Berk&Curt)Wei]的生物学特性,为香蕉棒孢霉叶斑病的综合防治提供科学依据.[方法]以采集自云南省香蕉种植区的香蕉棒孢霉叶斑病病叶片为材料,采用常规组织分离法进行病原菌单孢分离,并对病原菌进行形态特征观察及致病性测定;应用平板培养法进行病原菌生物学特性测定.[结果]香蕉棒孢霉叶斑病病原菌菌丝生长的最适培养基为马铃薯葡萄糖琼脂培养基(PDA);最适碳源为乳糖和甘露醇,最适氮源为蛋白胨;适宜温度为25~35℃,最适温度为28℃;病原菌仅能在pH 6~8内生长,最适pH为7;光照处理对菌丝生长有一定影响,以全黑暗条件下病原菌菌丝生长最快.在玉米粉培养基(CMA)上病原菌产孢量最高,光照与黑暗交替有利于产孢.病原菌菌丝致死温度和时间为58℃处理15 min,分生孢子的致死温度和时间为51℃处理5 min.[结论]香蕉棒孢霉叶斑病病原菌菌丝生长温度范围较宽,偏好高温,但适应的pH较窄;病原菌产孢的关键因子是培养基营养成分和光照条件.

Biological characteristics of pathogenic bacteria causing banana leaf spot disease

[Objective]The biological characteristics of Corynespora cassiicola(Berk & Curt)Wei,a pathogenic bacteria causing corynespora leaf spot of banana were studied to provide basis for comprehensive control of it.[Method]Banana leaves with corynespora leaf spot in Yunnan banana planting areas were collected.Conventional tissue separation was applied to isolate monospore from pathogenic bacteria,and morphological characteristics and the pathogenicity of the pathogenic bacteria were investigated.Biological characteristics of the pathogenic bacteria were detected by plating meth-od.[Result]Potato dextrose agar(PDA)was the optimal medium for hyphal growth.The optimum carbon sources were lactose and mannitol,the optimum nitrogen source was peptone.The suitable temperature ranged between 25-35℃,the optimal one was 28℃.The pathogenic bacteria could grow in pH 6-8,and the most suitable pH was 7.0.Light had certain effects on hyphal growth,and hypha grew at the fastest speed in dark.Corn meal agar(CMA)medium was the optimal cul-ture medium for sporulation;alternating light and dark could promote sporulation.Lethal temperature and time for hypha of the pathogenic bacteria were 58℃for 15 min,and 51℃for 5 min for conidia.[Conclusion]The temperature range for hypha growth of C.cassiicola is wide,and high temperature is more suitable for its growth.But the pH range is narrow. The key factor to sporulation is nutrient components of the media and light condition.