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1990年河南省中部秋播麦田小麦白粉病普遍发生。采集64个菌株,测其对32个已知抗白粉病基因品种(系)和推广品种毒力频卒结果,秋季菌源对Pm1、Pm3a、Pm3b、Pm3c和Pm5的毒力频率较高;对Pm2x和Pm2+6以及肯贵阿一号的频率较低;对Pm2和Pm8的频率已经上升;对许多推广品种毒力频率较高。说明目前存在着大面积感病寄主,生产上应做好化学防治准备。此外秋季菌源中存有极复杂的生理专化现象,其中对鉴别寄主低毒性的小种占优势。
Wheat germplasm occurred frequently in autumn wheat field in Henan Province in 1990. Sixty-four strains were collected and tested for virulence of 32 known powdery mildew resistant cultivars (strains) and popularized varieties. The virulence frequencies of Pm1, Pm3a, Pm3b, Pm3c and Pm5 were higher in autumn, The frequencies of Pm2x and Pm2 + 6, and Kennametal were lower; the frequencies of Pm2 and Pm8 had risen; and the frequency of virulence was higher for many of the promoted varieties. Indicating that there is a large area of susceptible host, production should be prepared to prevent chemical. In addition, there are very complicated physiological specializations in the autumn bacterial sources, among which, the race species with low toxicity to the host is dominant.