| To monitor the pathogenic changes of the stripe rust fungus of wheat in Shaanxi Province, 1 065 samples collected from 27 counties or districts of eight cities in Shaanxi Province and 100 samples gathered from Tianshui region in Gansu Province were identified on 19 universal differential hosts during 2006-2010. A total of 30 races and pathotypes were detected, namely CYR17, CYR20, CYR21, CYR22, CYR23, CYR27, CYR28, CYR29, CYR30, CYR31, CYR32, CYR33, Hybrid 46-4, 5, 6, 7, 8, 9, Shuiyuan11-1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12 and 13. Among these, CYR33 and CYR32 possessed wide distribution, high frequency and powerful pathogenicity. Therefore, they were the predominant races in Shaanxi Province. The next prevalent races were Su11-4, Su11-5, Su11-7 and CYR31. Because of low frequency and unstable occurrence in different years, races before CYR31 had been the secondary or uncommon races. Therefore, the wheat breeding programs for stripe rust resistance should mainly focus on CYR33 and CYR32, and give attention to Su11-4, Su11-5, Su11-7 and CYR31. |
