The infection of wheat powdery mildew to Elymus L. introduced from other countries

The resistance of eighteen Elymus species, grown in China and introduced from USA, Canada, Japan, Czech, etc. to wheat powdery mildew was tested with a mixture of 11 Chinese mildew races in greenhouse. The result showed that 15 species were successfully inoculated by the mildew pathogen. The mildew spores produced on 14 diseased Elymus species plants were collected and inoculated back to the wheat plants. The inoculation was also successful. The infection indicated that Elymus belonged to the wheat mildew host category in China. They have the potential to transmit powdery mildew pathogens. The possibility of the Elymus species transmitting new races in contiguous areas between countries was discussed.