安徽省水稻纹枯病菌对吡唑醚菌酯的敏感性及其与不同杀菌剂间的交互抗性

Sensitivity of Rice Sheath Blight Pathogen <i>Rhizoctonia solani</i> to Pyraclostrobin and Cross-Resistance against Diverse Fungicides in Anhui Province

采用菌丝生长速率法测定了该省15个地区的94株水稻纹枯病菌菌株对吡唑醚菌酯的敏感性,以明确安徽省水稻纹枯病菌Rhizoctonia solani对吡唑醚菌酯的敏感性及其与不同杀菌剂间的交互抗性,结果表明,供试94株水稻纹枯病菌菌株对吡唑醚菌酯具有较高的敏感性,所有菌株的有效抑制中浓度EC50在0.0409~1.2266 μg/mL之间,平均值为0.2721 μg/mL,其敏感性频率呈连续单峰曲线分布,符合正态分布,因此可将EC50平均值0.2721 μg/mL作为安徽省水稻纹枯病菌对吡唑醚菌酯的敏感基线;15个地区的菌株群体对吡唑醚菌酯的敏感性差异显著,同一地区的菌株个体间差异较大;吡唑醚菌酯与噻呋酰胺、丙硫菌唑及井冈霉素之间均不存在交互抗性。

To determine the sensitivity of rice sheath blight pathogen Rhizoctonia solani to Pyraclostrobin, and evaluate the cross-resistance between Pyraclostrobin and other fungicides, a total of 94 R. solani isolates collected from 15 regions in Anhui Province were used for testing their sensitivity to Pyraclostrobin using mycelial growth method. The tested isolates were highly sensitive to Pyraclostrobin, and the EC50 of these isolates to Pyraclostrobin were in the range of 0.0409~1.2266 μg/mL, with the mean value of 0.2721 μg/mL. The frequency curve of Pyraclostrobin was continuous and unimodal, and followed the normal distribution. Hence, the mean EC50 of 0.2721 μg/mL could be served as the baseline sensitivity of R. solani to Pyraclostrobin in Anhui Province. There was significant difference in the sensitivity to Pyraclostrobin among R. solani populations from 15 regions;there was an obvious difference in the sensitivity to Pyraclostrobin among individual isolate from same regions in Anhui Province. There was no notable evidence of positive cross-resistance between Pyraclostrobin and Jinggangmycin, thifluzamide and prothioconazole.