Application of molecular markers in breeding for leaf rust resistance in wheat

The breeding and cultivation of resistant wheat varieties is an effective way of controlling leaf rust. The use of molecular markers facilitates the incorporation of the major leaf rust resistance genes (Lr genes) responsible for resistance into new varieties and the pyramiding of these genes. Marker assisted selection was used to incorporate the currently effective Lr genes in Hungary (Lr9, Lr24, Lr25, Lr29, Lr35 and Lr37) into winter wheat varieties. The Lr genes were identifi ed using STS, SCAR and RAPD markers closely linked to them. Investigations were made on how these markers could be utilised in plant breeding, and near-isogenic lines resembling the recurrent variety but each containing a different Lr gene were developed to form the initial stock for the pyramiding of resistance genes or creating multiline varieties. Molecular markers are also ideal for the identifi cation of resistance genes in wheat genotypes with unknown genetic background. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 resistance genes has been demonstrated using molecular markers in the Martonvasar gene pool.