Genetic bases of barley resistance to the leaf stripe agent Pyrenophora graminea

Leaf stripe, caused by Pyrenophora graminea, is a serious disease of barley in many production areas. Genetic mapping of major genes and quantitative trait loci (QTLs) for this disease has revealed resistance loci on chromosomes 1 (7H), 2 (2H) and 3 (3H). QTLs for partial resistance have been identified in segregating populations derived from the crosses between Proctor and Nudinka, L94 and Vada, L94 and C123, and Steptoe and Morex. Major genes conferring a useful range of activity have been identified in the barley cultivars Vada and Thibaut. The Thibaut resistance gene, Rdg2a, has been subjected to high resolution mapping and a syntenic relationship of the resistance gene locus with rice chromosome 6 has been established. In the course of mapping major and quantitative disease resistance loci, molecular markers for resistance breeding for disease control using gene technology have been identified and validated for utilization in marker-assisted selection of disease resistance.