番茄叶霉病菌对多菌灵抗药性的诱导及抗性菌株特性研究

采用紫外线诱导及药剂驯化两种方法对番茄叶霉病菌的目标菌株进行多菌灵抗性诱导,分别经7、9代诱导后获得抗性突变体。突变体菌株的EC₅₀均大于500μg／mL,达高抗水平。突变体菌株与自然抗性菌株无药继代培养10代后,抗性程度没有明显变化。与亲本菌株比较,突变体菌株菌落生长速率、产孢量及产毒量有所下降。室内交互抗性测定表明:多菌灵与苯菌灵、菌核净及克霉灵之间具有正交互抗性,与瑞毒霉、扑海因及速克灵无交互抗性。乙霉威对多菌灵的高抗菌株表现负交互抗性或无交互抗性,但对敏感菌株不表现负交互抗性。

Resistance induction of Fulvia fulva (Cooke) Ciferri to carbendazim and bionomics of resistant-mutants

Carbendazim(MBC)-resistant mutants have been obtained by ultraviolet-induction and chemical-taming of Ful-via fulva(Cooke) Ciferri. The resistant index of mutants were higher than 5 000, belonging to high-level resistance. The fungicide resistance of mutants and wild-mutants were stable. The growth of colony, sporification and the production of phytoalexin were lower than their parent strains. MBC-resistant and sensitive isolates showed positive cross-resistance to benomyl, hzymexazol and imexazol. No cross-resistance to metalaxyl, procymidone and iprodione were observed. High-MBC resistant isolates showed negative cross-resistance or no cross-resistance to diethofencarb, but MBC-sensitive isolates showed no negative cross-resistance to diethofencarb.