In this study, we isolated and identified the pathogens by fulfilling Koch\'s postulates. Disease samples with typical spot blight symptoms were collected and pathogens were isolated from the diseased tissues. The pathogen was identified based on its biological characteristics and molecular analysis of internal transcribed (rDNA-ITS) and large subunit (LSU) sequences. Phylogenetic tree were constructed using MEGA7 software and pathogenicity tests were performed using in vivo inoculation. Finally, the pathogen was recovered and identified from the inoculated plants.
Based on Koch\'s postulates, we identified the pathogen causing spot blight on P. ternata as Stagonosporopsis cucurbitacearum. To our knowledge, this is the first study to explore spot blight on P. ternata caused by S. cucurbitacearum in China.
在这项研究中,我们通过履行科赫的假设来分离和鉴定病原体。收集具有典型斑点疫病症状的疾病样品,并从患病组织中分离病原体。根据其生物学特性和内部转录(rDNA-ITS)和大亚基(LSU)序列的分子分析鉴定了病原体。使用MEGA7软件构建系统发育树,并使用体内接种进行致病性测试。最后,从接种的植物中回收并鉴定病原体。
根据科赫的假设,我们确定了引起三叶斑枯病的病原体为南瓜孢霉。据我们所知,这是中国首次探索由葫芦枯病引起的斑点病的研究。