オオムギうどんこ病抵抗性遺伝子ml-oの各種菌株に対する反応

Eight powdery mildew strains, four collected from the field and the other four derived from a cross between two strains, were inoculated to seven mutant barley lines having the ml-o gene for powdery mildew resistance and their original varieties of barley. These eight powdery mildew strains showed a distinctive reaction to the nine testers having various resistant genes. Onthe other hand, the original barley varieties showed a similar reaction to all the powdery mildew strains inoculated, indicating that the genetic background of these varieties was similar. In comparison with the ml-o mutants and their original varieties, the type of lesion did not change in most cases, but the number of lesions decreased significantly without exception. In conclusion, the powdery mildew resistant gene ml-o does not affect the type of lesions but it reduces the number of lesions.