Leaf rust (LR) is one of the most important foliar diseases in wheat causing significant yield losses. The use of resistant varieties is a cheap, efficient and environmentally sound method to control wheat LR. Modern wheat varieties often harbour major resistance genes, which confer full protection against specific races of wheat rusts, and quantitative resistance conferring partial but durable resistance to mostly all the races of the pathogen. Although major resistance is easy-to-use in breeding programs, it tends to be short-lived against new compatible wheat rust races. Arguably, quantitative resistance is more durable but also difficult to handle due to its complex genetic architecture. The combination of both types of resistance in the same cultivar has been proposed the best strategy to achieve stable, broad-spectrum and long-lasting resistance to wheat rusts while reducing the use of costly and environmentally problematic fungicides. Many varieties of the Swiss genebanks are not used in breeding. Indeed, these “old” varieties or landraces have been abandoned because they did not meet requirements of traits selected by breeders (i.e. yield, grain quality …). However, their genetic material may contain resistance genes against diseases that were not looked for back now. In this project, we aim to screen an extensive series of modern varieties and landraces from Wallis (CH) in search of new qualitative and quantitative resistances against leaf rust effective under field conditions. By combining high-quality disease phenotyping tools and genome-wide association study (GWAS) on more than 500 wheat accessions comprising about 300 landraces and 200 improved cultivars, we will tap resistance sources, develop markers in order to getting insight into rust resistance mechanisms, and identify resistance genes. Preliminary results allowed identifying an important number of markers related to LR resistance in the study population. Among these SNPs, some have showed a high significance (p>0.00001) on chromosomes 1D, 6B, 7A and 7D. Interestingly, several markers highlighted potential candidate gene/QTL on chromosome 2D. This is the first report of Lr resistance genes on chromosome 2D in a winter wheat genome. This work will provide direct applications for practical breeding.