向日葵黄萎病病原鉴定及其生物学特性研究

PathogenIdentify and Biological Characteristics of Verticillium wilt of Sunflower

为更好地研究向日葵黄萎病发病规律及其有效防治方法,对向日葵黄萎病菌的形态和生物学特性进行了研究。结果表明：该病菌在梅干培养基上分生孢子透明无色,孢子梗基部为黑褐色,后期有黑色念珠状菌丝产生,未发现微菌核和厚垣孢子,证实为黄萎轮枝菌（Verticillium albo-atrumReinke et Berthold）。其菌丝生长的最佳条件为PSC,25℃,pH5~6,最适碳氮源为蔗糖和甘氨酸。产孢的最佳条件为PSC,25~30℃,pH8,最适碳氮源为D-木糖和L-组氨酸。孢子萌发的最适温度为25℃,最适pH5.9,偏酸偏碱均可促进萌发,6 h以后孢子即可萌发,12 h萌发率可达80%以上。

In order to better study the law of Verticillium wilt of sunflower and its effective control method,the morphology and biological characteristics of Verticillium albo-atrum of sunflower were studied through cultivation on culture medium PLYA.The results showed that hyaline conidia with conidiophores of dark-brown bases were produced on the medium,and black dormant mycelium appeared later with prolonged time of culturing.Microsclerotia and chlamydospores were not found.It seemed that the mycelium could grow better on PSC medium and the optimum growth conditions of the pathogen were 25℃,pH 5～6,and the optimal carbon and nitrogen sources were sucrose and glycine,respectively.For spore germination of pathogen,the optimum conditions were PSC medium,25℃and pH 8,the suitable carbon and nitrogen sources were D-xylose and L-histidine.The optimal conditions for spore germination were 25℃and pH 5.9,and it could be promoted when the culture medium was partial alkaline acidic or partial base.The spores begin to germinate after 6 hours where it cultured at 25℃ Incubator,and the germination rate would reach above 80% after 12 hours.