Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China.
Food Inspection and Testing Institute of Henan Province, Zhengzhou 450000, Henan, China.
Plant Dis. 2021 Jul;105(7):1951-1959. doi: 10.1094/PDIS-08-20-1764-RE. Epub 2021 May 12.
Garlic leaf blight caused by was first reported in Jiangsu Province in China. The dicarboximide fungicide (DCF) procymidone is reported to possess broad-spectrum action in inhibiting filamentous fungi and is widely used to control leaf disease of various plants. Of 41 isolates collected in this study from commercial garlic farms in Pizhou and Dafeng counties of Jiangsu Province, eight isolates were resistant to procymidone. The following three phenotypes were categorized according to in vitro responses to DCFs: sensitive, low resistance to iprodione and procymidone, and high resistance to all iprodione and procymidone. The fitness of all resistant isolates was decreased in accordance with data on mycelial growth, conidiation, and virulence. After treatment with 10 µg/ml of procymidone for 4 h, mycelial intracellular glycerol concentrations of resistant isolates were significantly lower than those of sensitive isolates. Positive cross-resistance was observed between dicarboximides and phenylpyrroles, but there was no cross-resistance between dicarboximides and fluazinam or difenoconazole in the two resistant phenotypes. Nucleotide sequence alignment of two-component histidine kinase genes from sensitive and resistant isolates indicated that amino acid mutations were located at the histidine kinase, adenylyl cyclase, methyl-accepting chemotaxis protein and at the phosphatase domain of the N-terminal region and the response regulator domain of the C-terminal region. To our knowledge, this is the first report of DCF resistance in , and these findings will help establish a rational strategy to manage DCF-resistant populations of in the field.
江苏省首次报道了大蒜叶枯病由引起。二甲酰亚胺类杀菌剂（DCF）腐霉利被报道具有抑制丝状真菌的广谱作用，广泛用于防治各种植物的叶部病害。本研究从江苏省邳州市和大丰市商业大蒜农场采集了 41 个分离株，其中 8 个分离株对腐霉利具有抗药性。根据对 DCF 的体外反应，将以下三种表型分为：敏感、对异菌脲和腐霉利低抗性和对所有异菌脲和腐霉利高抗性。所有抗性分离株的适应性均根据菌丝生长、产孢和毒力数据下降。经 10µg/ml 腐霉利处理 4 小时后，抗性分离株的菌丝细胞内甘油浓度明显低于敏感分离株。二羧酸类和苯并吡咯类之间存在正交叉抗性，但在两种抗性表型中，二羧酸类与氟唑菌酰胺或烯唑醇之间没有交叉抗性。来自敏感和抗性分离株的双组分组氨酸激酶基因的核苷酸序列比对表明，氨基酸突变位于组氨酸激酶、腺苷酸环化酶、甲基接受趋化蛋白和 N 端区域的磷酸酶结构域以及 C 端区域的响应调节蛋白结构域。据我们所知，这是腐霉利对的首次报道，这些发现将有助于在田间建立管理腐霉利抗性种群的合理策略。
