Genetic Control of High Protein Content and Its Association with Bread-Making Quality in Wheat

ABSTRACT

A population of recombinant inbred lines (RILs) developed from a cross of Triticum aestivum cvs. WL711 and PH132 using the single-seed descent method was used to investigate the genetics of high protein content and its contribution to bread-making quality. Four-year data on protein content of parents and 124 RILs suggested that the difference in protein content between the two parents was controlled by two major genes with an additive effect. The individual gene gave intermediate protein content. Seven RILs with high protein content and without any yield penalty were selected, multiplied, and investigated for various milling, dough, and bread-making characteristics. PH132 and all seven selected RILs had higher protein content, higher sodium dodecyl sulphate (SDS) sedimentation value, longer dough development time, a lower mixing tolerance index, higher stability, and better loaf volume and loaf quality than the bread wheat cultivars WL711 and PBW343. High molecular weight (HMW) glutenin subunit composition of various high-protein RILs indicated a recombination of parental protein subunits. “2?” coded by Glu-A1 locus, 17 + 18 subunits coded by Glu-B1 locus, and “5 + 10” coded by Glu-D1 locus were predominant. One of the selected RILs, T-74, possessing 2 + 12 at Glu-D1 locus, also had superior bread-making quality, indicating that grain-protein content above a certain minimum value is a relatively more important determinant of bread-making quality than HMW glutenin subunits 5 + 10.