为明确安徽舒城和巢湖地区甜瓜和栝楼蔓枯病的病原菌种类,2021-2022 年对该地区的甜瓜和栝楼蔓枯病的病组织进行病原菌的分离和培养,利用柯赫式法则验证其致病性.通过对分离菌株的形态学特征,以及ITS、LSU和TUB2 多位点序列分析,确定引起甜瓜及栝楼蔓枯病的病原菌为亚隔孢壳菌Stagonosporopsis citrulli.采用菌丝生长速率法测定了7 种杀菌剂对病原菌代表性菌株的室内毒力,结果显示,啶酰菌胺、咪鲜胺对其抑制效果较好,其EC50值在0.010 6~0.043 8 μg·mL-1,可优先选择这两种药剂进行轮换使用防治该病害.
To identify the pathogen causing gummy stem blight of Cucumis melo and Trichosanthes kirilowii,and screen effective fungicides for the management of this disease,symptomatic samples were collected from the fields lo-cated in Shucheng County and Chaohu City,Anhui Province in 2021 and 2022.Pure cultures were obtained consist-ently using tissue separation method,and five representative isolates were selected for morphological observation and molecular identification.Partial fragments of internal transcribed spacer(ITS)and large subunit(LSU)regions,be-ta-tublin 2(TUB2)genes of the isolates were amplified and sequenced.Pathogenicity assays were carried out to con-firm Koch's postulates.The pathogen was finally identified as Stagonosporopsis citrulli based on morphological charac-teristics and multi-loci sequence analysis.The indoor toxicity test results indicated that boscalid and prochloraz ex-hibited relatively higher inhibitory effects among seven fungicides,with both EC50 ranging from 0.010 6 to 0.043 8 μg·mL-1.The two fungicides could be preferentially utilized in rotation to control the disease caused by S.citrulli.