Mapping wheat powdery mildew resistance derived fromAegilops markgrafii

The pattern of inheritance of powdery mildew resistance expressed by two bread wheat (cultivar ‘Alcedo’)/Aegilops markgrafiiintrogression lines was explored using F2populations bred from crosses made with the powdery mildew-susceptible cultivar ‘Kanzler’. Disease reaction was tested at both seedling and adult plant stages. Two resistance loci, designatedQPm.ipk-1AandQPm.ipk-7A, were identified as mapping to the distal ends of chromosome arms 1AS and 7AL, respectively. WhereasQPm.ipk-1Awas expressed throughout the plant's life,QPm.ipk-7Awas only effective at the seedling stage. The map location of both resistance loci indicated that resistances originated fromA. markgrafii.The possible genetic relationship of these disease-resistant genes to knownPmgenes is discussed in the context of synteny.