Molecular Markers for Leaf Rust Resistance Gene Lr42 in Wheat

Leaf rust of wheat, caused by Puccinia triticina Eriks., is one of the most important wheat foliar diseases worldwide (Kolmer, 1996). Severe leaf rust epidemics can cause yield losses up to 40% (Knott, 1989). Growing genetically resistant cultivars is one of the most effective strategies to minimize yield losses due to the disease. To date, at least 71 genes for resistance to leaf rust have been cataloged in wheat (Singh et al., 2012). Of these, about half were introgressed from related species. Many of them were from Aegilops tauschii [syn. Triticum tauschii (coss.) Schmalh], the D genome donor of common wheat, including Lr21 (chromosom