Durable adult plant leave resistance in wheat

Leaf rust caused by Puccinia triticina is among the most prevalent leaf diseases of wheat worldwide. Despite that fungicides are available for leaf rust control, the use of resistant cultivars is economically and ecologically the best option for rust control. Leaf rust resistance may be governed by major genes (so called Lr-genes) and/or quantitative resistance genes. The Austrian cultivar Capo possesses durable adult plant leaf rust resistance, but does not possess any effective Lr gene to our knowledge. We will analyse the inheritance of its leaf rust resistance using molecular genetic tools. We will evaluate recombinant inbred line populations from crosses between the resistant line Capo and two susceptible wheat cultivars (Isengrain and Furore) for adult plant leaf rust resistance in replicated field experiments under high disease pressure at two locations during at least two seasons. We will quantify leaf rust severity and score infection type. In parallel we will analyse the population Capo/Isengrain with molecular markers (mostly SSR and AFLP), and construct a linkage map of this cross. The biometrical analysis of the resistance data together with the molecular marker data will allow to detect QTL (quantitative trait loci) for leaf rust resistance and to quantify their effects and interactions. The second population will be used for QTL validation. Up top now only few sources of durable adult plant leaf rust resistance have been molecular- genetically analysed. The project will contribute to the genetic and physiological characterization of adult plant leaf rust resistance in wheat. The ultimate goal of the project is to develop tools for use in marker assisted selection.