杧果露水斑病病原菌生物学特性测定

Biological characteristics of Cladosporium cladosporioides causing mango sooty blotch disease

【目的】明确杧果新病害露水斑病病原菌(Cladosporium cladosporioides)的生物学特性,以便为该病害的发生规律研究提供理论依据。【方法】测定了不同条件对病原菌菌丝生长、产孢量和孢子萌发的影响。【结果】菌丝在杧果葡萄糖琼胶培养基和PDA培养基上生长最佳,最适生长温度20℃,最适p H值7~8,光照对菌丝生长影响不明显,菌丝对有机碳源乳糖和有机氮源氨基乙酸利用最好,菌丝致死温度为50℃、10 min;产孢量以25℃、p H 6、光暗交替、麦芽糖为碳源、L-胱氨酸为氮源时最大;分生孢子萌发率以25℃、p H7、液态水、有机碳源阿拉伯糖、有机氮源L-天冬氨酸为最适条件,分生孢子致死温度50℃、10 min。【结论】杧果露水斑病菌喜好20~25℃、弱酸至弱碱、高湿、富含有机营养的环境。

【Objective】To provide a scientific basis for studying the epidemiology of mango sooty blotchdisease in field,a new disease on mango fruit,the biological characteristics of Cladosporium cladosporioides was tested.【Methods】This paper studied the effect of different conditions on mycelium growth,sporu-lation and spore germination of C. cladosporioides.【Results】For mycelial growth,the optimal mediumwas mango dextrose agar medium rich in organic nutrition. The optimum temperature was 20 ℃ and theoptimum p H value was 7-8. The effect of light was not significant. Lactose or nitrogen source glycine wasrespectively the optimum carbon or nitrogen source. Lethal temperature of mycelium was 50 ℃ for 10 min.For sporulation,the optimum temperature was 25 ℃ and the optimum p H value was 6. Alternation of lightand dark,maltose and L-acystine were in favour of sporulation. For spore germination,the optimum tem-perature was 25 ℃,the optimum p H value was 7,and the optimum RH was liquid water. Organic carbonsource arabinose or nitrogen source L-asparaginate were in favor of spore germination. Lethal temperatureof spore was 50 ℃ for 10 min.【Conclusion】It showed that the environment of 20-25 ℃,p H 6-8 withhigh humidity,and medium rich in organic nutrition were favorite to C. cladosporioides.