布朗李叶枯病菌生物学特性研究

对布朗李叶枯病菌(Macrophoma kawatsukai Hara)生物学特性研究表明,该菌最适生长和产孢的培养基为布朗李果汁。菌丝生长和产孢的最佳碳源分别为蔗糖、麦芽糖和果糖;氮源分别为酪氨酸、谷氨酰胺、天门冬酰胺和半胱氨酸。菌丝生长最适温度25℃,最适pH5～7;分生孢子形成最适温度25～30℃,最适pH8,饱和湿度有利于产孢,阳光照射形成分生孢子器最多,紫外光照射对分生孢子器形成有一定的抑制作用。孢子萌发最适温度为20～30℃,最适pH6～9,相对湿度为90%～100%,以在水滴中萌发最好。布朗李杆煎汁和布朗李果汁对孢子萌发有促进作用。

Biological characteristics of the pathogenic fungus causing leaf spot disease of Prunus americana

The biological characteristics of Macrophoma kawatsukai Hara causing leaf spot disease of Prunus americana were investigated in vitro.The results indicated that one of the optimum media for its growth and sporulation was the fruit juice of Prunus americana.For its growth and sporulation,the best carbon sources were sucrose,maltose and fructose,while the best nitrogen sources were tyrosine,glutamine,asparagine and cysteine.For mycelial growth,the optimum temperature was 25℃ and the optimum pH was 5-7.25-30℃,pH 8 and RH100% were the best conditions for sporulation.Sunlight was beneficial for sporulation but treatment of ultraviolet light could cause significant reduction in sporulation.The optimum temperature for conidial germination was 20-30℃ and the optimum pH was 6-9.If the relative humidity reached 100% or the conidia were in water,the percentage of conidial germination was the highest.The stem tissue extracts and fruit juices of Prunus americana could promote conidial germination.