抗氰烯菌酯假禾谷镰孢突变体的诱导及其生物学特性

为评估引起小麦茎基腐病的病原菌假禾谷镰孢Fusarium pseudograminearum对氰烯菌酯的抗性风险，对5株敏感菌株进行了室内药剂驯化，获得33株抗性突变体，突变频率为16.5%,其对氰烯菌酯的抗性水平范围为7.39～1 665.76倍，3株表现低抗，4株表现中抗，26株表现高抗；发现在myosin-5基因上存在11种抗性突变类型，其中217位的丝氨酸突变为亮氨酸(S217L)、420位的谷氨酸突变为赖氨酸(E420K)和135位的丙氨酸突变为苏氨酸(A135T)为主要突变类型，其比例分别为45.5%、15.2%和9.1%。S217L型抗性突变体的产孢量显著下降，菌丝生长速率和致病力与亲本菌株无显著差异。E420K型抗性突变体的菌丝生长速率和致病力显著下降，产孢量与亲本菌株无显著差异。A135T型抗性突变体的菌丝生长速率和产孢量与亲本菌株无显著差异。研究结果表明假禾谷镰孢在药剂选择压力下易形成氰烯菌酯的抗性群体，对氰烯菌酯存在中到高等的潜在抗性风险，其myosin-5的点突变与其对氰烯菌酯的抗性相关。

Induction and biological characteristics of phenamacril-resistant mutants of Fusarium pseudograminearum

In order to assess the resistance risk of Fusarium pseudograminearum to phenamacril, a total of 33 phenamacril-resistant mutants were obtained through spontaneous selection with a mutation frequency of 16.5%, and the resistance level of these mutants to phenamacril ranged from 7.39 to 1 665.76 times, with three mutants showing low resistance, four mutants showing moderate resistance and 26 mutants showing high resistance. Eleven types of resistance mutations were found in myosin-5 gene. A serine (S) to leucine (L) transition at position 217 (S217L), a glutamic (E) to lysine (K) transition at position 420 (E420K), and an alanine (A) to threonine (T) transition at position 135 (A135T) were major mutation types, with a frequency of 45.5%, 15.2% and 9.1%, respectively.compared with the parental strains, the spore production of the type S217L resistant mutants was significantly decreased, but there was no significant difference in mycelial growth rate and pathogenicity. Mycelial growth rate and pathogenicity of the type E420K resistant mutants were significantly decreased, and no significant difference was observed in spore production. The point mutation of myosin-5 was related to its resistance to phenamacril. The pathogenicity, mycelial growth rate and spore production of A135T resistant mutants were not significantly different from the parental strains The results suggested that F. pseudograminearum could easily form the phenamacril-resistant population under the pressure of fungicide selection, and had a moderate or high risk of resistance to phenamacril.