辽宁省玉米北方炭疽病菌的分离鉴定及生物学特性
Isolation, identification and biological characteristics of Aureobasidium zeae in Liaoning Province

为明确辽宁省疽病的致病菌及其生物学特性,通过形态学和分子生物学方法鉴定了致病菌,并利用十字交叉法和血球计数板计数法研究了致病菌的生物学特性。系统发育树显示,分离菌株SYND-12与出芽短梗霉Aureobasidium pullulans亲缘关系最近,位于同一分支,并与玉蜀黍出芽短梗霉Aureobasidium zeae聚为一类,分子鉴定结果与形态学鉴定结果一致,表明引起辽宁省玉米北方炭疽病的致病菌为玉蜀黍出芽短梗霉A. zeae (Narita et Hiratsuka) Dingley。该病菌菌丝生长温度范围为10~30℃,最适温度为25℃,最适pH为7,光照条件为全黑暗,适宜的碳、氮源和培养基分别为蔗糖、硝酸钾和马铃薯葡萄糖琼脂培养基;其分生孢子产生的最适碳源为葡萄糖,其它最适宜生长条件与菌丝相同,该病菌在添加不同氮源的水琼脂培养基中均不产生分生孢子;其分生孢子萌发的最适条件为28℃、pH 8、光暗交替,最适碳、氮源分别为麦芽糖和牛肉膏,单一氮源条件对分生孢子的萌发有抑制作用。
In order to clarify the causal agent and its morphological characteristics of maize eye spot, the pathogenic fungus of maize eyespot disease was identified by using morphological and molecular methods, and morphological characteristics of Aureobasidium zeae were studied with crossing method and hemocytometer. The results showed that SYND-12 had the closest relationship with A. pullulans located in the same branch, and clustered with A. zeae; morphological and molecular proofs indicated that maize eyespot disease was caused by A. zeae (Narita et Hiratsuka) Dingley in Liaoning Province. A. zeae could grow under 15-30℃, with optimal condition at 25℃, pH 7, dark, sucrose, potassium nitrate, PDA, and the largest sporulation quantity was observed at 25℃, pH 7, dark, glucose, and the largest conidial germination was found at 28℃, pH 8, alternating light and dark, maltose, and beef extract. No conidial production of A. zeae was observed by adding different nitrogen sources into water agar plates and conidial germination was inhibited by adding single nitrogen source.