High‐molecular‐weight glutenin subunit alleles and compositions modulate gluten quality and dough rheology in 20 wheat near‐isogenic lines

BACKGROUND: High-molecular-weight glutenin subunits (HMW-GSs) are key determinants of wheat gluten quality and dough rheological properties. However, complex genetic backgrounds in natural populations and the limited subunit diversity of available near-isogenic lines (NILs) constrain precise evaluation of allelic effects and locus interactions. In this study, 20 HMW-GS NILs developed using the cultivar 'Xiaoyan 22' as the recurrent parent genetic background were evaluated over two growing seasons. Protein content, gluten characteristics, farinograph parameters, and extensograph properties were measured to assess the effects of GLU-A1, GLU-B1, and GLU-D1 loci, allelic variants, seasons, and their interactions. RESULTS: Multifactor analysis of variance showed that growing season mainly affected grain protein content, gluten content, dough water absorption, and several rheological traits, whereas HMW-GS loci predominantly influenced gluten index and dough rheology. The GLU-D1 locus contributed most strongly to gluten quality and dough properties, and the GLU-B1 × GLU-D1 interaction was the most prominent among locus interactions. Allelic effects on dough strength generally followed 2* > 1 > N at GLU-A1. At GLU-B1, 13 + 16 and 17 + 18 enhanced dough strength, and 7 + 8 was generally superior to 7 + 9. At GLU-D1, 5 + 10 significantly improved gluten index, dough stability time, farinograph quality number, and maximum resistance to extension. Allelic effects on extensibility typically trended inversely to those on strength. Among HMW-GS combinations, N/7 + 8/5 + 10, N/17 + 18/5 + 10, and 1/7 + 9/5 + 10 conferred higher dough strength but lower extensibility, whereas 2*/7 + 9/2 + 12 and 1/7 + 9/4 + 12 combined favorable dough strength with comparatively greater extensibility. CONCLUSION: These findings clarify HMW-GS allelic effects and provide a theoretical basis for wheat quality improvement targeting different end-use applications. © 2026 Society of Chemical Industry.