Development of Hexaploid Wheat Germplasm with Resistance to Both Powdery Mildew and Stripe Rust by Introgression of Pm60 and YrU1 from Triticum urartu

Wheat powdery mildew and stripe rust, caused by Blumeria graminis f. sp. tritici (Bgt) and Puccinia striiformis f. sp. tritici (Pst), respectively, are two devastating diseases that threaten global wheat production. Long-term reliance on a limited number of resistance genes can accelerate resistance breakdown. Triticum urartu (2n = 14, AuAu), the progenitor of the wheat A subgenome, serves as a valuable gene pool for disease resistance. In this study, we identified three T. urartu accessions exhibiting high resistance to Bgt and Pst. Molecular marker analysis indicated that PI 428215 and PI 428315 carry Pm60b, whereas CITR 17664 carries both Pm60 and YrU1. Durum–T. urartu amphiploids (AABBAuAu) displayed resistance responses identical to their T. urartu parent and were used as bridges to transfer these resistance genes into a common wheat (AABBDD) background. Using marker-assisted selection (MAS), recurrent backcrossing, selfing, and phenotypic screening, we developed wheat lines carrying Pm60, Pm60b, YrU1, or Pm60 + YrU1. Segregation analysis in backcross-derived populations supported the functionality of these genes in the common wheat background. The selected introgression lines have high resistance to Bgt and Pst and showed no obvious adverse agronomic effects, providing useful germplasm for wheat disease resistance breeding. This study used a “multi-resistance, multi-combination” pyramiding strategy by MAS to introduce resistance genes from wild wheat into common wheat.