Composition of HMW and LMW glutenin subunits and their effects on dough properties, pan bread, and noodle quality of Chinese bread wheats

Knowledge of composition of high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS) and their associations with pan bread and noodle quality will contribute to genetically improving processing quality of Chinese bread wheats. Two trials including a total of 158 winter and facultative cultivars and advanced lines were conducted to detect the allelic variation at Glu-1 and Glu-3 loci by SDS-PAGE electrophoresis and to understand their effects on dough properties, pan bread, and dry white Chinese noodle (DWCN) quality. Results indicate that subunits/alleles I and null at Glu-A1, 7+8 and 7+9 at Glu-B1, 2+12 and 5+10 at Glu-D1, alleles a and d at Glu-A3, and alleles j and d at Glu-B3 predominate in Chinese germplasm, and that 34.9% of the tested genotypes carry the 1B/1R translocation (allelic variation at Glu-D3 was not determined because no significant effects were reported previously). Both variations at HMW-GS and LMW-GS/alleles and loci interactions contribute to dough properties and processing quality. For dough strength related traits such as farinograph stability and extensigraph maximum resistance and loaf volume, subunits/alleles 1, 7+8, 5+10, and Glu-A3d are significantly better than those of their counterpart allelic variation, however, no significant difference was observed for the effects of d, b, and f at Glu-B3 on these traits. For extensigraph extensibility, only subunits I and 7+8 are significantly better than their counterpart alleles, and alleles d and b at Glu-B3 are slightly better than others. For DWCN quality, no significant difference is observed for HMW-GS at Glu-1, and Glu-AM and Glu-B3d are slightly better than other alleles. Glu-B3j, associated the 1B/1R translocation, has a strong negative effect on all quality traits except protein content. It is recommended that selection for subunits/alleles 1, 7+8, 5+10, and Glu-AM could contribute to improving gluten quality and pan bread quality. Reducing the frequency of the 1B/1R translocation will be crucial to wheat quality improvement in China.