中文摘要：

【目的】明确苹果轮纹病菌对二甲酰亚胺类杀菌剂腐霉利的敏感性现状,建立敏感基线。【方法】采用菌丝生长速率法,测定了采自山东、辽宁、河北、河南、山西和陕西等地的106株苹果轮纹病菌对腐霉利的敏感性,比较了不同省份苹果轮纹病菌对腐霉利的敏感性差异。【结果】腐霉利对供试的106个苹果轮纹病菌菌株的EC50值差别不大,在0.327 0～3.322 8 mg·L-1,平均EC50为（1.289 1±0.060 0）mg·L-1,呈连续性偏正态分布,可以作为田间苹果轮纹病菌对腐霉利的敏感基线。其中,陕西省的苹果轮纹病菌对腐霉利的敏感程度最高,其他依次为山西省、河北省、辽宁省和河南省,山东省的敏感性最低,山东省的EC50平均值是陕西省2.63倍。【结论】田间苹果轮纹病菌对腐霉利的敏感性水平较高,未发现敏感性下降的抗药性群体,所测得的EC50平均值可作为苹果轮纹病菌对腐霉利的敏感基线。

英文摘要：

[ Objective ]Apple ring rot, caused by Botryosphaeria dothidea, is one of the most important dis- eases in apples and it is widely distributed in most apple production areas in China. The most effective management strategy for controlling this disease is the application of chemical fungicides. The wide appli- cation of chemical fungicides inevitably leads to serious fungicide-resistance problems, and results in more difficulties to control this disease in the fields, Procymidone is a dicarboximides fungicide, which has been widely used to protect apples from fungal infection in both the growing season and postharvest period. The objective of this study was to determine the sensitivity level and baseline of B. dothidea to pro- cymidone using 106 field isolates collected from Shandong, Hebei, Henan, Liaoning, Shanxi and Shaanxi, respectively. [Methods] The sensitivity of each isolate to procymidone was determined by using a mycelial growth assay by PDA containing serial concentrations of procymidone. Techincal grade procymidone （a.i. 98.3%） was dissolved in 100% acetone, adjusted to a concentration of 10 000 mg·L-1 stock solution, and was diluted with 0.1% （60） polysorbate 80 in water to seven concentrations： 1.25, 2.5, 5.0, 10.0, 20.0, 40.0 and 80.0 mg· L-1, then added to the PDA medium to produce eight standard concentrations： 0, 0.125, 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0 mg of procymidone per liter of the medium. A 7 mm mycelial plug, cut from the edge of 4 days old B. dothidea colony, was placed on the center surface of the PDA plate and amended with each concentration of the procymidone. Four replicate plates were used for each concentration. The radial growth was determined by measuring the diameter of the colonies after 4 days of incubation. The ef-fective concentration EC50 （concentration which reduced mycelial growth by 50%） was calculated by re- gressing the radial growth values （100% control） against the log 10 values of the fungicide concentrations using SPSS16.0 software. The cumulat