贵州小麦白粉菌毒性结构及品种抗性分析

Virulence Constitution of Erysiphe graminis f. sp. tritici and Cultivar Resistance to Powdery Mildew in Guizhou

1996～1997年，用采自贵州17个县（市）的124个小麦白粉病菌株，分别接种在9个鉴别品种上，鉴定出30个小种：出现频率最高，分布最广的是315号小种，其次是311、1、3、7、15和377号小种；低毒力、中毒力和高毒力三类小种群的出现频率分别为24．2％、15．3％和60．5％。用其中的39个菌株对21个已知抗性基因的品种（系）进行毒性频率测定，并将这些品种和其它品种对1995和1996两年进行异地病圃鉴定，结果表明，（1）在室内测定毒性频率较高（在50％以上）、在病圃反应型和严重度达到3级或3级以上的品种，包括含有pm1、pm3a、pm3b、pm4a、pm4b、pm5、Pm8、pm4＋8和pm1＋2＋9基因的品种；（2）在室内测定毒性频率较低（在25％以下）、在病圃反应型和严重度达到2级或2级以下的品种，包括含有pm12、pm17、pm18、pm19、pm21、pm2＋6、pm2＋6＋1、pm2＋M1d、pm2＋4、pm2＋4＋6和pm2＋4b＋8基因的品种；（3）在室内测定毒性频率较高（25％～50％）、但在病圃反应型和严重度较低（2～3级）的品种，包括含有pm2、pm6、pm7、pm11和pm4＋2x基因的品种；（4）贵州省内推广品种多数不抗病或已丧失了抗性，后备品种（系）中的三属麦、JYP系列、野二燕4号、斯燕93—1，丰优6号和兴义7号等抗病性很好。

During 1995- 1997, 124 isolates of Erysiphe graminis f. sp. tritici, collected from 17 counties in Guizhou Province wereinoculated on 9 differential cultivars respectively. Thirty physiological races were identified. Among them, race 315 had thethe highest frequency and the widest distribution, followed by races 311, 1, 11, 7, 15 and 377. The incidence frequencyof the three race groups, low, middle and high virulence, were 24. 2%, 15. 3% and 60. 5 %, respectively. Determinationof frequency for 39 isolates to 21 cultivars carrying known resistant genes in three disease nurseries in 1995 and 1996 showedthat, (1) Cultivars with virulence frequencies over 50%, and reaction type and serious degree in nursery equal to or overGrade 3 included those carrying the genes pm1, pm3a, pm3b, pm4a, pm4b, pm5, pm8, pm4 +8 and pml1+ 2+9; (2) Cultivarswith virulent frequency less than 25 % and reaction type and serious degree equal to or lower than Grade 2 included those carrying genes pm12, pm17, pm18, pm19, pm21, pm2+6, pm2+6+1 , pm2+Mild, pm2+4, pm2+4+6, pm2+4+6+8; (3) Cultivars with higher virulent frequency (25 % - 50% ) but lower serious degrees (Grade 2 - 3), involved the ones carrying the genes pm2, pm6, pm7, pm11, pm2x+ 4 ; (4) Most of the commercial cultivars in Guizhou Province had no resistanceor lost resistance to powdery mildew. The reserve cultivars San Shu Mai, JYP- 1, JYP-2, JYP-3, Ye-er yan 4. St Yan93-1, Feng You 6 and Xing Yi 7, had higher resistance to powdery mildew in the field.Kegwords: Wheat Powdery mildew Virulence constitution Resistance of Cultivar Guizhou