BACKGROUND: High-molecular-weight glutenin subunits (HMW-GSs) have important effects on bread-making quality. Allelic variations of HMW-GS in bread wheat varieties contribute in different ways to dough properties and bread volume. However, no systematic analysis has been done on the effects of allelic variation on bread-crumb structure, an important parameter when evaluating bread-making quality. In this study, seven Glu-1 deletion lines and one intact line harboring different encoding loci and derived from a cross between two spring wheat cultivars were used to investigate the contribution of a single Glu-1 locus, or combination of Glu-1 loci, to the crumb structure. RESULTS: Deletion of HMW-GS locus combinations resulted in a decline in slice size, brightness, and fineness of the bread crumb. A desirable crumb structure correlated well with preferred subunit combinations: high levels of GMPs, superior dough properties, and loaf volume. The effects of the HMW-GS combinations were ranked as Dx5 + Dy10 > Bx17 + By18 > Ax1 + Null. The Ax1 + Null allele affected the crumb structure by interacting with the Bx17 + By18 or Dx5 + Dy10. CONCLUSION: High-molecular-weight glutenin subunits had significant effects on the loaf volume and crumb structure; varying effects from different subunit combinations were observed.
BACKGROUND: High-molecular-weight glutenin subunits (HMW-GSs) have important effects on bread-making quality. Allelic variations of HMW-GS in bread wheat varieties contribute in different ways to dough properties and bread volume. However, no systematic analysis has been done on the effects of allelic variation on bread-crumb structure, an important parameter when evaluating bread-making quality. In this study, seven Glu-1 deletion lines and one intact line harboring different encoding loci and derived from a cross between two spring wheat cultivars were used to investigate the contribution of a single Glu-1 locus, or combination of Glu-1 loci, to the crumb structure. RESULTS: Deletion of HMW-GS locus combinations resulted in a decline in slice size, brightness, and fineness of the bread crumb. A desirable crumb structure correlated well with preferred subunit combinations: high levels of GMPs, superior dough properties, and loaf volume. The effects of the HMW-GS combinations were ranked as Dx5 + Dy10 > Bx17 + By18 > Ax1 + Null. The Ax1 + Null allele affected the crumb structure by interacting with the Bx17 + By18 or Dx5 + Dy10. CONCLUSION: High-molecular-weight glutenin subunits had significant effects on the loaf volume and crumb structure; varying effects from different subunit combinations were observed.