Evaluation of Resistance to Stem Rust and Identification of Sr Genes in Bread Wheat Cultivars in Türkiye

Stem rust caused by Puccinia graminis f. sp. tritici ( Pgt ) is more destructive disease of wheat on a global scale. In this study, reactions of the 150 bread wheat cultivars were evaluated on the natural Pgt infection at adult-plant stage in 2020 and 2021 and they were also analyzed by using the specific molecular markers to detect resistance genes ( Sr22 , Sr24 , Sr25 , Sr26 , Sr31 , Sr38 , Sr50 and Sr57 ). Based on the phenotypic data, the majority of the cultivars (62%) showed resistance/moderate resistance reactions to natural Pgt infection. According to the molecular findings, the genes Sr57 (in 103 cultivars), Sr50 (in nine cultivars), Sr25 (in six cultivars) and Sr22 , Sr31 and Sr38 (in one cultivar) and their combinations Sr25  +  Sr50, Sr31  +  Sr57, Sr38  +  Sr50 , Sr38  +  Sr57 were detected in these cultivars. However, Sr24 and Sr26 were determined none of them. These resistance genes were identified for the first time during this study. In addition, the findings may be used to develop resistant cultivars in rust disease breeding programs.