苏丹草大斑病菌的生物学特性研究

Biological Characteristics of the Pathogenic Fungus Sudan Grass Large Leaf Spot Pathogen

对苏丹草大斑病菌生物学特性的研究，为进一步探讨该病的流行规律及制定综合防治措施提供理论依据。本试验研究了温度、pH、光照、营养条件对苏丹草大斑病菌营养生长的影响及温度、pH、湿度、营养条件对该菌孢子萌发的影响。结果表明，苏丹草大斑病菌生长的温度范围为10～35℃，最适温度为25℃；pH范围5．0～9．0，最佳为8．0；光照对菌丝生长无显著影响。在试验的培养基中以PDA＋苏丹草种子煎汁是生长最好的。该菌孢子萌发的温度为10-35℃，最适温度为20℃；pH范围3．0～9．0；在相对湿度为100％的条件下容易萌发，水滴中更易萌发。1％的葡萄糖液、1％乳糖液、1％蔗糖液及2％苏丹草种子煎汁都能促进孢子萌发，而1％蔗糖液是最适宜该菌孢子萌发的液体环境。生物学特性表明，该菌对营养要求不高，对环境适应力较强的病原菌。

Study on biological characteristics of sudan grass large leaf spot pathogen in order to provides theoretical basis for further in vestigate on epidemic law and making comprehensive control measures of the pathogen. Effect of temperature, pH, light, nutrition conditions on vegetative growth and spore germination of Sudan grass large leaf spot pathogen was studied. The results show that the pathogenic fungi could grow within temperature 10 - 35 ℃, optimal temperature was 25℃ ; The suitable pH range is 5.9 - 9.0, optimal pH was 8.0 ; Light gave no significant effect on the mycelium growth. PDA and the decoct juice of Sudan grass seed meal agar were optimal medium. Temperature range for spore germination was 10 - 35 ℃, optimal temperature was 20 ℃ ; pH range was 3.0 - 9.0 ; 1% glucose solution, 1% sucrose solution, 1% lactose solution and 2% the decoct juice of Sudan grass seed all can increase the speed of spore germination and 1% sucrose solution was the optimal condition. Biological characters observation shows that this strain is pathogenic one with lower nutrition requirements but strong adaption ability to environment.