Quality and flour-blending effects of wheat lines with triple null alleles at the Glu-1 locus

High-molecular-weight glutenin subunits (HMW-GS) determine the elasticity of wheat dough. The null HMW-GS alleles had potential value in modifying the end-use quality of weak gluten wheat. The quality of wheat lines with triple null alleles at the Glu-1 locus (3 N lines) was tested and compared with non-3 N controls. Most 3 N lines had significantly higher protein content, degree of softening, and ratios of low-molecular-weight glutenins (LMW-GS) to glutenins than the non-3 N controls. The 3 N lines had significantly lower Zeleny-sedimentation values, gluten-related indices, and development and stability times; lower contents of LMW-GS and glutenins; and lower ratios of glutenin to gliadin than the non-3 N lines. The contents of the gliadin fractions of the 3 N lines were close to or even higher than those of the non-3 N lines. These results suggest that the 3 N lines had weaker gluten strength than the non-3 N flours. Two 3 N flours were blended with five base flours to test their effects on biscuit quality. Blending the 3 N flours with five base flours at certain ratios could improve some biscuit quality indices, such as increase the slice area and the extensibility factor and decrease the thickness of biscuit. The 3 N flours could be used to improve the biscuit-making quality.