小麦抗白粉病基因在甘肃的有效性及评价

采自甘肃各地的小麦白粉菌株接种在含有已知抗白粉病基因的小麦品种(系)上，测定其毒性频率，并对这些品种进行了异地成株期抗性鉴定。根据已知抗病基因对白粉苗群体的抗性程度，对其进行抗性效能的评价。结果表明，Pml、Pm3c、Pm3f、Pm5、Pm6、Pm7、Pm8和Pm17在甘肃抗性差，已失去利用价值；Pm2、Pm3a、Pm3b、Pm19抗性较低，不宜单独作为抗源利用；Pm4b、Pm13、Pm20、Pm21和含有Pm4的白兔3号、肯贵阿1号及含有Pm“XBD”的我国农家品种小白冬麦抗性表现好，可作为抗性亲本利用。组合基因如Pm2 6、Pm2 Mld、Pml 2 9等都表现出较好的抗性，这表明利用抗源材料进行基因累加有望培育出优良的抗性品种。文中还结合抗源材料的农艺性状对其利用提出了建议。

Effectivity and evaluation of the resistant genes to wheat powdery mildew in Gansu Province

To evaluate the resistant genes of 23 wheat varieties (lines) to powdery mildew caused by Erysiphe graminis f. sp. tritici in Gansu, we defected the virulence frequency for 77 isolates of E. graminis in 14 counties using artificial inoculations on wheat varieties with known resistant genes and identified their resistance at adult stage. Results indicate that Pm1, Pm3c, Pm3f, Pm5, Pm6, Pm7, Pm8 and Pm l7 were little resistant to trial isolates, providing no applicable value in breeding; Pm2, Pm3a, Pm3b and Pml9 with lower resistance should not be utilized as the only resistant sources; Pm4b, Pml3, Pm20, Pm21, Pm4 (Baimian 3 and Kenguia 1) and Pm"XBD"(Xi-aobaidongmai, endemic cultivar) provided very high resistance to E. graminis f.sp. tritici and may be applicated as resistant parents. The study also shows that combinations of genes such as Pm2 + 6, Pm2 + Mld and Pml +2 + 9, etc. , were very effective to the isolates. This may indicate using gene combinations of resistant sources can get highly resistant varieties. Some suggestions have been proposed for the application of resistant materials based on their agronomic characters.