Disomic 1U (1B) <i>Triticum aestivum</i>–<i>Aegilops umbellulata</i> Substitution Lines with Superior Dough Microstructure and Breadmaking Quality

The U genome of <i>Aegilops umbellulata</i> possesses rich gluten protein alleles, which can potentially be used to improve wheat processing quality. Wheat-<i>Ae. umbellulata</i> introgression lines are promising germplasm resources for the genetic improvement of wheat quality. A disomic 1U (1B) <i>Triticum aestivum</i>-<i>Ae. umbellulata</i> substitution line, 1266, was identified from a distant hybridization cross and used for quality evaluation. Notably, 1266 showed normal chromosome pairing and demonstrated comparable or even superior agronomic and seed size-related traits to one to three of its three wheat parents. The introduction of Ux and Uy subunits in 1266 had positive effects on major quality-related parameters, such as an increase in the contents of grain protein and low-molecular-weight glutenins, γ-gliadin, and gliadins, compared to its three parents. Further, 1266 had a more compact and stable dough microstructure, along with superior breadmaking quality, compared to its three parents, and thus, 1266 is an important bridge material for wheat quality improvement that introduces quality-associated genes from <i>Ae. umbellulata</i>.