作 者：
成世杰;范昆;张彬彬;张凯伦;付丽;夏晓明
关键词：
苹果轮纹病菌;甲基硫菌灵;克菌丹;代森联;敏感性
摘 要：
【目的】检测我国主要苹果产区田间苹果轮纹病菌对甲基硫菌灵、克菌丹和代森联3种杀菌剂的敏感性现状。【方法】采用菌丝生长速率法,检测了我国6个省份的106株苹果轮纹病菌对3种杀菌剂的敏感性,采用Spearman’s秩相关系数法对3种杀菌剂的敏感性分别进行两两相关分析,比较了不同省份苹果轮纹病菌对同一种杀菌剂的敏感性差异。【结果】甲基硫菌灵对苹果轮纹病菌的EC50值介于0.814 5~10.700 8 mg·L~(-1),平均为(3.357 9±0.160 7)mg·L~(-1),敏感性频率分布呈连续性偏正态分布,田间苹果轮纹病菌对甲基硫菌灵仍然较为敏感。克菌丹的EC50值介于1.672 2~38.487 3 mg·L~(-1),呈不连续单峰曲线,有敏感性下降的菌株XY7(采自河南信阳,EC50为38.487 3 mg·L~(-1))出现。剔除该菌株后,剩余105个菌株对克菌丹的敏感性频率分布呈连续偏正态分布,EC50平均值为(10.268 1±0.460 0)mg·L~(-1),可建立田间苹果轮纹病菌对克菌丹的敏感基线。代森联的EC50值介于1.276 3~32.132 4 mg·L~(-1),平均为(15.511 9±0.710 7)mg·L~(-1),敏感性频率分布呈连续性偏正态分布,可建立田间苹果轮纹病菌对代森联的敏感基线。相关性分析结果表明,甲基硫菌灵和代森联、克菌丹和代森联之间的敏感性不存在相关性,但甲基硫菌灵和克菌丹的敏感性呈显著正相关。不同省份苹果轮纹病菌对同一种杀菌剂的EC50平均值不存在明显差异(P>0.05)。【结论】田间苹果轮纹病菌对甲基硫菌灵、克菌丹和代森联的敏感性水平相对较高,并建立了田间苹果轮纹病菌对克菌丹和代森联的敏感基线。
译 名：
The sensitivity of Botryosphaeria dothidea to thiophanate-methyl,captan and metiram
作 者：
CHENG Shijie;FAN Kun;ZHANG Binbin;ZHANG Kailun;FU Li;XIA Xiaoming;College of Plant Protection, Shandong Agricultural University;Shandong Institute of Pomology;
单 位：
College of Plant Protection, Shandong Agricultural University%Shandong Institute of Pomology
关键词：
Botryosphaeria dothidea;;Thiophanate-methyl;;Captan;;Metiram;;Sensitivity
摘 要：
【Objective】Botryosphaeria dothidea is widely distributed in most apple growing regions in China, causing ring rot disease of apple. For many years, use of chemical fungicides has been effective for controlling the disease in the areas of apple production. However, the effectiveness of these fungicides has been threatened by the emergence of resistant pathogens in the field. Thiophanate-methyl, captan and metiram have been widely used for controlling the disease in China for many years. So far there has been no report on the sensitivity of B. dothidea to these fungicides in China. The objective of this study was to detect the sensitivity level of B. dothidea to thiophanate-methyl, captan and metiram using 106 field isolates collected from Shandong, Hebei, Henan, Liaoning, Shanxi and Shaanxi, respectively.【Methods】The sensitivity of B. dothidea to fungicides was assessed based on inhibition of mycelial growth by PDA containing serial concentrations of fungicides. Technical grade thiophanate-methyl(a.i. 95.0%), captan(a.i.95.0%), and metiram(a.i. 87.0%) were dissolved in 100% acetone, respectively, being adjusted to a concentration of 10 000 mg·L~(-1) stock solution. The stock solution was diluted with 0.1%(ω) polysorbate 80 in water to eight concentrations: 5.0, 10.0, 20.0, 40.0, 80.0, 160.0, 320.0 and 640.0 mg·L~(-1), then added to the PDA medium to produce eight standard concentrations: 0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0, 32.0 and 64.0 mg of each fungicide per liter of the medium. A 7-mm-diameter agar disk taken from the margin of a 4-day-old B. dothidea colony were placed at the center surface of a series of petri dishes(9 cm diameter)containing PDA amended with various concentrations of fungicides. Four replicate plates were used for each concentration. Mycelial growth was quantified after 4 days of incubation at 26 ℃ in darkness by measuring two perpendicular diameters of the growth ring in each plate, and taking the average(the diameter of the original plug subtracted). The effective concentration EC50(concentration which reduced mycelial growth by 50%) was calculated by regressing the radial growth values(100% control) against the log10 values of the fungicide concentrations using SPSS 16.0 software. The cumulative frequency distribution of EC50 value was produced and calculated by using SPSS 16.0 software. The bin width of the histogram was calculated by Scott's rule and the normal distribution of the EC50 values of the 106 isolates was analyzed using the Shapiro-wilk test. Cross-resistance patterns were analyzed by lg EC50 values using the Spearman rank correlation and a line regression analysis. The differences of the sensitivities among B. dothidea isolates collected from different provinces were statistically analyzed using a one-way analysis of the variance(ANOVA) with the SPSS 16.0 software, and means were separated using the Student Newman Keuls(SNK) test.【Results】The EC50 values of 106 B. dothidea field isolates collected from different provinces of China to thiophanate-methyl varied from 0.814 5 to 10.700 8 mg·L~(-1), with an average of(3.357 9±0.160 7)mg·L~(-1). The frequency distribution of EC50 values of 106 isolates to thiophanate-methyl was continuous,unimodal and positively skewed according to the Shapiro-wilk test results. The sensitivities of B. dothidea field isolates to thiophanate-methyl were still in high levels. The EC50 values to captan were from 1.672 2 to 38.487 3 mg·L~(-1), with discontinuous frequency distribution curve. Isolate XY7(Henan province) had the highest EC50 values to captan(38.487 3 mg·L~(-1)) among the 106 isolates. However, the frequency distribution of EC50 values of the other 105 isolates to captan was continuous, unimodal and positively skewed according to the Shapiro-wilk test results. The mean EC50 values of the other 105 isolates were(10.268 1±0.460 0) mg·L~(-1), which could be used as the sensitivity baselines of B. dothidea to captan. The EC50 values of 106 B. dothidea field isolates to metiram were from 1.276 3 to 32.132 4 mg·L~(-1), with an average of(15.511 9±0.710 7) mg·L~(-1). The frequency distribution of EC50 values of the 106 isolates to metiram was continuous, unimodal and positively skewed according to the Shapiro-wilk test results. Therefore,the sensitivity baseline of B. dothidea to metiram could be established in this study. Spearman rank correlation analysis by lg EC50 values indicated that there were positively significant correlations between sensitivities of B. dothidea isolates to thiophanate-methyl and captan(r=0.281 3, P=0.003 5), but there were no significant correlations between sensitivities of B. dothidea isolates to thiophanate-methyl and metiram(r=0.179 7,P=0.065 3), captan and metiram(r=0.081 1, P=0.408 6), respectively. There were no significant differences among the sensitivities of 106 B. dothidea field isolates to each fungicide using the SNK test at P=0.05 level(P>0.05)【.Conclusion】The 106 B. dothidea field isolates showed a relatively high sensitive level to thiophanate-methyl, captan, and metiram, respectively. The sensitivity baselines of B. dothidea to captan and metiram could be established according to this study.
