山西省小麦白粉病菌毒性结构初步分析

利用４３个山西省的小麦白粉菌株对３６个已知抗白粉病基因品种（系）和推广品种（系）进行毒力频率测定，结果表明对Ｐｍｌ，Ｐｍ３ａ，Ｐｍ５，Ｐｍ７，Ｐｍ８的毒力频率较高，不宜单独应用，对Ｐｍ４ａ，Ｐｍ４ｂ，Ｐｍ２ｘ，Ｐｍ２＋６及肯贵阿１号的毒力频率较低，是高抗基因，Ｐｍ２，Ｐｍ６介于以上两种类型之间，有一定的利用价值。对许多推广品种（系）毒力频率较高，说明目前存在着大面积感病寄主，生产上应做好防治准备。此外，菌源中存有极复杂的生理转化现象，其中对鉴别寄主低毒性的小种占优势。

Preliminary Analysis of Venomous Construction of Powdery Mildew in Wheat in Shanxi Province

Using 43 strains of powdery mildew in wheat in Shanxi province, the frequency of virulence was tested for 36 varieties (Lines) containing known gene of resistance to powdery mildew and commercial varieties(Lines) in this study. The results showed that strains of powdery mildew have higher frequency of virulence to Pm1, Pm3a, Pm5,Pm7,Pm8 and single use is not suitable. For Pm4a, Pm4b,Pm(2x),Pm(2+6)and No. 1 of kenguai have lower frequency of virulence, which is high resistance gene. Pm2,Pm6 is between the two types mentioned above and has some utilizable value. Strains of powdery mildew was proved higher frequency of virulence on many varieties, which demonstrated the host of sensitive disease existed in big area. Physiological specialization of quite complexity in the strains was revealed and the race of lower toxity for rost appraising was dominating.