九种杀菌剂对新拟盘多毛孢病菌的室内毒力作用

新拟盘多毛孢叶斑病是在草莓上发现的一种新病害。本研究对采自北京昌平、山东诸城、云南保山及广东惠州等地草莓Fragaria × ananassa发病叶片进行了组织分离，结合形态特征和ITS系统发育分析对所分离获得的8株疑似拟盘多毛孢叶斑病病菌进行了鉴定，并采用菌丝生长速率法测定了病原菌对8种代表性杀菌剂及新型药剂——双苯菌胺的敏感性。结果表明:所分离得到的病原菌为新拟盘多毛孢Neopestalotiopsis clavispora；双苯菌胺对8株新拟盘多毛孢 N. clavispora的毒力最强，平均EC₅₀值为 (0.004 ± 0.002) μg/mL，可作为防治草莓叶斑病的首选药剂；其次为咪鲜胺、嘧菌酯、戊唑醇、氟环唑、苯醚甲环唑和腈菌唑，平均EC₅₀值在0.006~0.803 μg/mL之间；百菌清毒力较低，而代森锰锌对新拟盘多毛孢 N. clavispora几乎没有抑制作用。研究结果对合理使用杀菌剂防治草莓新病害——新拟盘多毛孢叶斑病提供参考。

Laboratory toxicity of nine fungicides against Neopestalotiopsis clavispora

Neopestalotiopsis leaf spot is a new disease on strawberry. The pathogens of the new strawberry leaf spot disease from Changping district, Beijing, Zhucheng city, Shandong Province, Baoshan city, Yunnan Province, Huizhou city, Guangdong Province and other regions were isolated and identified. The pathogen was identified by morphological analysis and ITS phylogenetic analysis. Sensitivities of 8 isolates to 8 commonly used fungicides and SYP-14288 were determined by indoor inoculation. The results showed that the pathogen was Neopestalotiopsis clavispora. SYP-14288 had a strong inhibitory effect on the mycelia growth of 8 isolates of N. clavispora, with an average EC₅₀ value of (0.004 ± 0.002) μg/mL, which could be used as the first choice for the control of strawberry leaf spot disease. The mean of EC₅₀ values were 0.006-0.803 μg/mL for prochloraz, azoxystrobin, tebuconazole, epoxiconazole, difenoconazole, and myclobutanil, respectively. Chlorothalonil exhibited lower toxicity. while mancozeb had the lowest inhibitory activity. Those results are important for the rational application of fungicides in the chemical control of Neopestalotiopsis leaf spot, a new disease of strawberry.