小麦白粉病菌对三唑酮抗药性的监测

小麦白粉病是世界性病害,因缺少抗性品种,长期以来依赖于药剂防治。三唑类药剂是防治白粉病的高效药剂,由于长期、大量、单一的应用,致使病菌抗药性发生。我国胶东沿海是小麦白粉病的多发地区,使用三唑酮防治该病近10年,病菌抗药性的研究与探明对农业生产具有指导意义。应用小株法和叶段法进行小麦白粉菌对三唑酮抗药性监测,3年共监测单孢堆菌系333个。结果较基线MIC高3～7倍者占86％,表明已进入抗药性发展初期。由于近年春旱抑制发病而抗药性发展很慢,一旦白粉病有中度以上流行条件,大面积连续用药即会发生抗药性,使防治失效,威胁生产,建议尽早治理。

MONITORING OF RESISTANCE OF WHEAT POWDERY MILDEW TO TRIADIMEFON

Powdery mildew of wheat occurs seriously in Shandong Province. Triadime-fon is the main fungicide to control the disease and has being used for ten years. With entire plant method and leaf tip method,we monitored the resistance of Erysiphe graminis f. sp. tritici to triadimefon from 1992 to 1994. As a result,the MIC value of 86 percent of all 333 single pustules isolates is 3 -7 times as high as the baseline value. That means the resistance of the pathogen is in emergence in this area. As the weather was draught in past three years,the development of resistance is slow. If the conditions suit the epidemic of the powdery mildew for several years and the disease is controlled only by triadimefon in large area,the resistance of wheat powdery mildew must breakout,and the fungicide will fail to control the disease, and that results in the loss of crop. So we suggest that management for resistance to triadimefon should be done as early as possible.