福建省玉米小斑病菌的生物学特性研究

[目的]为明确福建省玉米小斑病病菌的生物学特性，[方法]以选自福建省建瓯、沙县和福州地区的3株玉米小斑病菌菌株为研究对象，研究了温度、湿度、pH值、光照、营养对病菌菌丝生长、产孢量和孢子萌发的影响。[结果]结果表明，菌丝生长最适温度和pH分别为30℃和6；产孢最适温度和pH分别为25℃和6~7；孢子萌发最适温度和pH分别为25~28℃和6。光照能显著抑制病菌产孢，在相对湿度为85%、95%条件下或在水琼脂培养基表面上，孢子萌发率分别达50%、88%和90%。葡萄糖、乳糖、甘露醇、可溶性淀粉适宜病菌菌丝生长和孢子形成，而尿素、硫酸铵、硝酸铵、氯化铵能显著抑制菌丝生长、孢子形成和孢子萌发。菌丝体的致死温度为65℃、10 min或60℃、30 min，分生孢子的致死温度为60℃、10 min或55℃、30 min。[结论]3个菌株的产孢特性、菌丝致死温度和致病力均存在明显的差别。

Biological Characteristics of Bipolaris maydis in Fujian Province

To determine the biological characteristics of Bipolaria maydis in Fujian Province, three B. maydis isolates, collected from Jian’ou, Shaxian and Fuzhou areas, were selected as research objective. The effects of temperature, moisture, pH values, light and nutrition on the mycelial growth, sporulation quantity and conidia germination were studied. The results showed that the optimum temperature and pH value for mycelium growth were 30℃ and 6; the optimum temperature and pH value for spore production were 25℃ and 6-7; and the optimum temperature and pH value for conidia germination were 25-28℃ and 6. Light could significantly inhibit the sporulation. Under the condition of relative humidity of 85%, 95% or on water agar, the percentage of conidia germination reached 50% , 88% and 90% , respectively. Glucose, lactose, mannitol and soluble starch were suited for mycelial growth and sporulation. However, urea, ammonium sulphate, ammonium nitrate, ammonium chloride could significantly inhibit the mycelial growth, spore production and conidia germination. The lethal temperature for hypha was 65℃ for 10 min or 60℃ for 30 min, while the lethal temperature for the spores was 60℃ for 10 min or 55℃ for 30 min. Three isolates were obviously different in characteristics of sporulation, lethal temperature of hypha and the pathogenicity.