蒲公英叶斑病病原分离鉴定与生物学特性研究

Pathogen Identification and Biological Characteristics of Dandelion Leaf Spot Disease

为明确甘肃省定西市渭源县等地蒲公英(Taraxacum mongolicum Hand.-Mazz)叶斑病病原菌及其生物学特性。采用组织分离法对病原菌进行分离,通过观察病原菌形态特征、柯赫氏法则致病性测定,并基于ITS、TEF1、rpb2基因序列分析,对病原菌进行鉴定。引起蒲公英叶斑病的病原真菌为细极链格孢(Alternaria tenuissima),其在PSA培养基上长势最好;最佳生长碳源为葡萄糖,可溶性淀粉最适合产孢;最佳生长氮源为有机氮源蛋白胨;最适生长的pH为8;最适生长温度为25℃。

To identify the pathogens and investigate the biological characteristics of Taraxacum mongolicum Hand leaf spot disease in Weiyuan County,Dingxi City,Gansu Province,the pathogenic bacteria were isolated using tissue separation method.The morphological characteristics of the original bacteria were observed,and the pathogenicity was determined according to Koch’s postulates.The pathogenic bacteria were identified through ITS,TEF1 and rpb2 gene sequence analysis.The results showed that Alternaria tenuissima was the pathogen of dandelion leaf spot,with optimal mycelium growth observed on PSA medium.The glucose was identified as the best carbon source for its growth,and preptone was the optimal organic nitrogen source.The pathogen exhibited optimal growth at a pH of 8 and a temperature of 25℃.This study elucidated the pathogenic bacteria responsible for dandelion leaf spot and characterized their biological traits,providing a theoretical foundation for the future prevention and management strategies.