3株甘薯干腐病菌的生物学特性研究

Study on Biological Characteristics of Three Pathogenic Strains of Dry Rot in Sweet Potato

为了明确3株甘薯干腐病菌的生物学特性,采用单因素试验并利用十字交叉法和血球计数对其菌丝生长和产孢数量进行了研究。结果表明:菌株GF1Y和GF2Y在碱性较强的环境下菌丝生长速度更快,而菌株GF3Y对酸碱度不敏感;GF1Y和GF2Y对光照不敏感,而GF3Y在完全光照条件下生长速度最慢;3个菌株在不添加碳源或氮源条件下均能较快生长,但是其菌丝均较稀薄;3个菌株的产色素能力随着pH值、氮源等条件的不同而变化;GF1Y的菌丝致死温度为58℃,10 min,GF2Y和GF3Y的菌丝致死温度均为60℃,10 min;GF1Y的孢子致死温度为48℃,10 min,而GF2Y和GF3Y的孢子致死温度均为50℃,10 min;GF1Y和GF3Y的产孢量很低,因此不同条件对其产孢量的影响较小;GF2Y的最适产孢条件为pH 9、完全光照、以葡萄糖为碳源,以尿素为氮源。

In order to identify the biological characteristics of three pathogenic strains of dry rot in sweet potato,we carried out single-factor experiments to study the mycelial growth and sporulation quantity of these strains by using cross method and blood cell count.The results showed that the mycelial growth of strains GF1Y and GF2Y was faster under alkaline environment,while strain GF3Y was not so sensitive to pH-value.GF1Y and GF2Y were not sensitive to illumination,while the mycelial growth of GF3Y was the slowest under the condition of 24-h illumination.Under the condition of not adding any carbon source or nitrogen source into culture medium,these 3 strains all could grow rapidly,but their mycelia were relatively thin.The pigment-producing capacity of three strains varied with the changes in pH-value and nitrogen source of culture medium.The hyphal lethal temperature of GF1Y,GF2Y and GF3Y was 58℃,60℃and 60℃for 10 min,respectively.The sporular lethal temperature of GF1Y,GF2Y and GF3Y was 48℃,50℃and 50℃for 10 min,respectively.Various conditions had little influences on the sporulation quantity of GF1Y and GF3Y due to their very low sporulation quantity.The best conditions for the sporulation of GF2Y were:pH 9,24-h illumination,using glucose as carbon source,and using urea as nitrogen source.