[Genetic analysis and gene deduction of powdery mildew resistance in T. durum-Ae. squarrosa amphidiploids].

Eleven seedlings with resistance and two amphidiploids with disease resistance at all developmental stage were screened by using No. 15 isolate of E. graminis f. sp. tritici to inoculate 99 T. durum-Ae. squarrosa amphidiploids. The two amphidiploids with disease resistance at all developmental stage, M53 and M81, and their Ae. squarrosa parents were resistant to No. 15 isolate of powdery mildew payhogen, but their T. durum parents were susceptible. Therefore, the powdery mildew resistance of M53 and M81 were derived from Ae. squarrosa. Amphidiploid M74, which had the same durum parent as M53 but different Ae. squrrosa parent, was susceptible to No. 15 isolate in adult stage. M29 and M35, which had the same durum parent as M81 but different Ae. squarrosa parent were susceptible in all stage. These results were also proved that the powdery mildew resistance genes were derived from Ae. sqarrosa. Genetic analysis showed that powdery mildew resistance gene in M53 or M81 was a single dominant gene. A series of lines with known powdery mildew resistance genes and two unknown lines were used to test response patterns with 14 differential isolates of E. graminis f. sp. tritici. The response patterns in M53 and M81 were different from Pm1 to Pm21 and indicated that M53 and M81 conferred a new powdery mildew resistance gene respectively.