紫花苜蓿菌核病病原鉴定及其主要生物学特性

Identification and control of Medicago sativa sclerotinia stem rot occurred in south Jiangsu hilly area

菌株NJ1分离自苏南丘陵地区苜蓿菌核病株.通过病原菌致病性测定和形态学特征观察,结合病原菌核糖体转录间隔区(ITS)序列分析,将病原菌鉴定为三叶草核盘菌(Sclerotinia trifoliorum).对该病原菌生物学特性研究表明,菌株NJ1菌丝生长最适温度为18～23℃;最适pH值为5～9;病原菌对硫酸铵利用能力强,对L-半胱氨酸利用能力差;对甘露醇和乳糖利用最好,D-果糖和D-木糖利用较差,不能利用柠檬酸.

Strain NJ1 was isolated from M. sativa sclerotinia rot stem in south Jiangsu hilly. It was identified as Sclerotinia trifoliorum through pathogenicity determination, morphology observation and analysis of nucleotide sequence of internal transcribed spacer (ITS). Further biological study on strain NJ1 revealed that the optimal temperature for sclerotium germination and mycelium development was between 18-23℃. Mycelium of NJ1 could grow at pH 3-12, with the optimum 5-9. Ammonium sulphate was the favorable nitrogen source for mycelium growth, whereas cysteine nearly could not be used by strain NJ1. Among the tested carbon sources, luscious and lactose were useful types, whereas citric acid was not.