Wheat glutenin allele 1Ax2∗ improves dough and bread quality without compromising yield.

High yield and good quality are two predominant objectives of most of the wheat breeding programs. Modulating HMW-GS composition is an effective approach to improve grain quality without yield penalty. In this study, we first analyzed the background similarity of three near-isogenic lines (NILs) with 1Ax-null, 1Ax1 or 1Ax2∗ alleles in the background of cultivar Xiaoyan-22 at the protein and DNA levels. On this basis, the yield, yield-related agronomic traits, flour, dough, and bread qualities of the three lines were studied in the 2021-2022 and 2022-2023 seasons. The results showed that, compared to the 1Ax-null allele, the grain yield of the 1Ax1 or 1Ax2∗ allele was not changed, and the 1Ax1 allele averagely decreased protein yield by up to 4.9% and dough yield by up to 6.5%. Notably, the grain yield of the 1Ax2∗ allele was higher than that of the 1Ax1 allele. Meanwhile, compared to the 1Ax-null allele, the 1Ax1 allele averagely increased unextractable polymeric protein content (UPP%) by up to 5.8%, and dough stability time by up to 27.8%, which increased specific volume by up to 4.2%, and the 1Ax2∗ allele averagely increased UPP% by up to 24.2% and dough stability time by up to 111.1%, which increased specific volume by up to 14.4%. These findings indicate that introgression of the 1Ax2∗ allele has a potential to increase wheat quality without negatively affecting grain yield, which provides glutenin allele selection for breeding high-yield and high-quality wheat cultivars in the background of wheat cultivar Xiaoyan-22 and other similar cultivars.