白三叶草一种叶斑病病原菌的分离鉴定

明确在山东省聊城市白三叶草上发现的一种叶斑病的病原菌,以期为该病害的防控提供参考.2019年采集山东省聊城市东昌府区具有叶斑病的白三叶叶片,利用组织分离法分离病原菌,并依据柯赫式法则验证致病性.在形态学观察的基础上,对病原菌进行分子生物学鉴定,构建系统发育树,分析其遗传多样性.从发病叶片中分离得到病原菌(标记为SY1)...

Isolation and Identification of the Pathogen Causing Leaf Spot on Trifolium repens

An investigation in Liaocheng of Shandong Province shows that a pathogen causing leaf spot was found on Trifolium repens. Therefore, it is of great significance to find out the pathogen species and provide reference for the prevention and control of the disease. The leaves of T. repens with spot disease collected from Liaocheng were used as materials. The pathogenic bacteria were separated by tissue separation method, and the pathogenicity was verified by Koch's rule. Based on morphological observation, molecular biological method was used to identify pathogenic bacteria. The phylogenetic tree was constructed to analyze the fungus genetic diversity. The pathogenic bacteria (labelled SY1) isolated from diseased leaves were pathogenic and consistent with the field symptoms. To further classify the taxonomic status of the pathogen, the generic fungal primers ITS4/ITS5 were used for PCR amplification and sequencing. Sequence analysis showed that the SY1 was 100% similar to Alternaria arborescens (serial number: KC464334.1), and gathered together on the phylogenetic tree. According to the morphological characteristics and gene sequence identification results, the pathogen of T. repens leaf spot was identified as A. arborescens, which was the first report of A. arborescens causing T. repens leaf spot in China.