Effect of Triadimefon Seed Coating Treatment on the Germination and Infection of Blumeria graminis f. sp. Tritici in Wheat Seedling

The effect of triadimefon seed coating treatment (Tri SCT) on the development of germination and infection of Blumeria graminis f.sp. tritici in wheat seedling was examined by means of histopathology methods . The observation showed that 1)Tri SCT had no effect on formation of primary germ tube, appressorium germ tube, and formation of mature appressoria . Percentage of malformed appressoria increased significantly; 2)With Tri SCT , the formations of central body of haustoria and development of haustorial fingers were inhibited , and successful infection percentage decreased; 3)Growth of primary hypha, formation of elongating secondary hypha, and development of secondary haustoria were restrained or ceased because of Tri SCT. Tri SCT played an important role in reducing the beginning population of this fungus and control of wheat powdery mildew.