| Popis: |
Powdery mildew, caused by Blumeria graminis f. sp. tritici , is one of the most important diseases in wheat ( Triticum aestivum L.) worldwide. Breeding for resistance is the most economical and effective method for controlling the disease. Tangmai 4 carries a pair of T1BL·1RS wheat-rye ( Secale cereale L.) translocated chromosomes and is resistant to a wide spectrum of wheat powdery mildew isolates. Genetic analysis indicated that a single semidominant gene in Tangmai 4 conferred resistance to powdery mildew, temporarily designated PmTm4 . Segregating F 2 population and their F 3 progenies derived from the cross between Tangmai 4 and Clement were used for bulked segregation analysis. Four SSR, one EST-SSR, and one EST-STS polymorphic markers were linked to the powdery mildew resistance gene PmTm4 in an order of Xcau12–Xgwm611–PmTm4–XEST92–Xbarc1073–Xbarc82 . Gene PmTm4 was physically mapped on the distal bin of chromosome 7BL using Chinese Spring nullisomic-tetrasomic, ditelosomic, and deletion lines. The results demonstrate that PmTm4 gene may be either an allele at the Pm5 locus or a member of closely linked cluster of genes. |
