新疆苹果黑星病菌野生型菌株对腈菌唑的敏感性基线

Baseline sensitivities of apple scab(Venturia inaequalis)to myclobutanil in Xinjiang,northwestern China

为建立苹果黑星菌对腈菌唑的敏感性基线,对田间苹果黑星菌的抗药性监测和病害防治提供科学指导,选用从新疆长期未施任何化学农药的废弃果园中采集分离的37个苹果黑星菌野生型菌株,采用分生孢子萌发法和菌丝生长速率法进行不同浓度梯度杀菌剂腈菌唑(myclobutanil)的敏感性测定。结果表明:苹果黑星菌对腈菌唑的敏感性分布范围为0.028-1.017mg/L,平均值为0.283mg/L。本研究结果和检测方法对监测施药果园中苹果黑星菌对腈菌唑敏感性的动态变化,以及为指导病害防治有效药剂的选择和风险评估提供了理论依据。

Thirty-seven wild isolates of Venturia inaequalis,causal agent of apple scab,were collected from abolished orchards without application of fungicides in Xinjiang for determining the baseline sensitivity of the pathogen to myclobutanil in order to monitor fungicide-resistance of the pathogen and disease control in the field.Baseline sensitivity of Venturia inaequalis to myclobutanil were tested by use of in vitro bioassay methods of determining conidial germ tube elongation and monoconidial hyphal growth rates of the fungus cultivated on fungicide-amended agar with various concentrations of myclobutanil.The EC50 of the baseline population was determined,ranging from 0.028 mg/L to 1.017 mg/L,with a mean value of 0.283 mg/L.The tested isolates show certain sensitivities to myclobutanil,and no resistant isolates are found in the treated orchard.The in vitro tests imply that the baseline of 0.460 mg/L could be used as a value to monitor V.inaequalis resistance to myclobutanil and disease control risk assessment for fungicide application in orchard.