RESUMO
The aim of this study was to clarify the effects of the high-molecular-weight glutenin subunits (HMW-GSs) 1Dx3+1Dy12 (3+12) and 1Dx4+1Dy12 (4+12) at the Glu-D1 locus on gluten and Chinese steamed bread (CSB) quality. The grain protein content and composition, gluten content and gluten index, farinograph properties, and CSB quality were investigated using four wheat near-isogenic lines (NILs) carrying HMW-GSs 1Dx2+1Dy12 (2+12), 3+12, 4+12 and 1Dx5+1Dy10 (5+10), respectively. The unextractable polymeric protein (UPP) and glutenin macropolymer (GMP) content, gluten index, dough development time, stability time, and farinograph quality number of four NILs all ranked as 5+10 > 3+12 > 2+12/4+12, such as the gluten index ranked as 5+10(44.88%) > 3+12(40.07%) > 2+12(37.46%)/4+12(35.85%); however, their contributions to the quality of CSB were ranked as 3+12 > 5+10 > 2+12/4+12, such as the specific volume ranked as 3+12(2.64 mL/g) > 5+10(2.49 mL/g) > 2+12(2.36 mL/g)/4+12(2.35 mL/g), which indicated that a suitable gluten strength (3+12) was crucial to making high-quality CSB. In addition, subunits 4+12 had a similar quality performance to low-quality subunits 2+12. All these findings suggested that, except for the acknowledged high-quality subunits 5+10, the introduction of 3+12 at the Glu-D1 locus is an efficient way for quality improvement of gluten as well as CSB.