番茄早疫病菌对异菌脲的敏感基线及其抗性突变体的生物学特性

采用菌落直径法测定了山西省五寨县42株番茄早疫病菌Alternaria solani菌株对异菌脲的敏感性。结果表明,异菌脲对各菌株的EC50值在1.225~2.674 μ g/mL之间,平均为2.556 μ g/mL, 由于所有菌株均采自未使用过异菌脲的地区,该平均值可作为番茄早疫病菌对异菌脲的相对敏感基线。为了评价番茄早疫病菌对异菌脲的抗性风险,以敏感菌株为试材,通过紫外诱导和药剂驯化(10代)的方法获得了21株抗性突变体,比较了敏感菌株和突变体的生物学特性。结果表明:异菌脲对突变体的EC50值均大于100 μ g/mL,达到高抗性水平;突变体的抗药性稳定,在无药PDA平板上继代培养10次后抗性不丧失;突变体在生长速率及致病力方面较敏感菌株有所下降,产孢量及分生孢子萌发率与敏感菌株相比无显著差异,孢子的竞争能力明显弱于敏感菌株。

Baseline sensitivity of Alternaria solani to iprodione andcharacteristics of the resistant mutants

The sensitivity of 42 strains of Alternaria solani collected from Wuzhai in Shanxi Province to iprodione was measured.The results showed that EC50 values of different strains of A.solani varied from 1.225 μ g/mL to 2.674 μ g/mL with the mean value of 2.556 μ g/mL,which could be regarded as the baseline sensitivity of A.solina to iprodione because the 42 strains were collected from the field where iprodione were never applied.To evaluate the resistant risk of A.solina to iprodione,21 iprodione-resistant mutants were induced by UV irradiation and 10 generation fungicide adaption in laboratory,and the characteristics of resistant mutants and sensitive strains were measured.The results showed that EC50 values of mutants were more than 100 μ g/mL which were high resistance level.And the resistance obtained was stable.Compared with sensitive strains,the mycelium growth and pathogenicity,especially the competition ability of the mutants were declined.However,the sporulation and germination were similar with that of the sensitive ones.