Introgression of a Novel Ug99-Effective Stem Rust Resistance Gene into Wheat and Development of Chromosome-Specific Markers via Genotyping-by-Sequencing (GBS).

is a wild relative of common wheat ( L.) with resistance to f. , the causal agent of stem rust, including the highly virulent race TTKSK (Ug99). In order to transfer resistance, - amphiploids were initially developed and used as a bridge to create wheat- introgression lines. Conserved ortholog set (COS) markers were used to identify chromosome introgression lines, which were then subjected to seedling f. resistance screening with race TTKSK. A COS marker-verified line carrying chromosome 2V with TTKSK resistance was further characterized by combined genomic in situ and fluorescent in situ analyses to confirm a monosomic substitution line MS2V(2D) (20″ + 1' 2V[2D]). This is the first report of stem rust resistance on 2V, which was temporarily designated as . To facilitate the use of this gene in wheat improvement, a complete set of previously developed wheat- disomic addition lines was subjected to genotyping-by-sequencing analysis to develop chromosome-specific markers. On average, 350 markers per chromosome were identified. These markers can be used to develop diagnostic markers for -derived genes of interest in wheat improvement.