用活动苗圃法测定小麦白粉菌群体的变异

1991年在重庆市6个县、区,用活动苗圃法测定田间小麦白粉菌群体的变异。结果表明,含有Pm2,4b、MlkPm4b、MliPm6抗性基因组合的小麦品种Sappo、Turbo、Bert和含Ba单基因的品系81—7241都高抗白粉病。而含Pm4a、Pm4b、Pm6、Mlk抗性基因的Khapli/Cc8、Armada、Timgalen、Herold品种以及含Pm2x、KG基因的白免3号、肯贵阿和含有Pm2,6基因组合的CI12632品种,虽然在大部分地区中也高度抗病,但在个别地点或县却表现感病。对这类抗源品种,应特别留意其病菌毒性变异。活动苗圃能及时侦察到病原群体中某些稀有的、具潜在危险的毒性小种,可作为一种补充监测方法。

THE USE OF MOBILE NURSERIES IN ASSESSMENT OF VARIATION IN FIELD POPULATION OF WHEAT POWDERY MILDEW

Mobile nurseries were used to assess variation in field population of Blumeria graminis f.sp. tritici(=Erysiphe graminis f.sp.tritici) in Chongqing;in 1991.The result showed that wheat cultivars Sappo, Turbo and Bert, Which carry the resistance gene combinations Pm2,4b, M1kPm4b, and M1iPm6, respectively, and the line 817241, which carrying the monogene Ba, were highly resistant to powdery mildew, and that cultivars Khapli/Cc8, Armada, Timigalen, Herold, Baimian3 and Ken-Gui-A, which carry the genes Pm4a, Pm4b,Pm6,M1k, Pm2x and KG, respectively, and cultivar CI 12632, which carry the combination Pm2,6, were also resistant, but they were susceptible in some fields. Therefore, the shift of virulence of the fungus should be monitored on these cultivars. Conducive to the detecting of rare and potential dangerous races in the pothogen population, this technique is valuable for evaluating the variation of wheat powdery mildew.