The Relative Amounts of HMW Glutenin Subunits of OS Wheat Cultivars in Relation to Bread-Making Quality

Abstract

Qualitative and quantitative variation of high molecular weight (HMW) glutenin subunits is very important for wheat bread-making quality. The aim of this investigation was to estimate the relative amounts (%) of HMW glutenin subunits in OS winter wheat cultivars and their contribution to bread-making quality by SDS-PAGE and scanning densitometry. In this paper 10 winter wheat cultivars created at Agricultural Institute Osijek (OS) and cultivar Divana (Jost-Sjeme, KriŽevci), as Croatian standard improver, were investigated. The wheat quality evaluation was done by indirect parameters, rheological properties of dough and baking test. The quantitative analysis of HMW glutenin subunits have demonstrated that subunits encoded at Glu-D1 locus (Dx2, DylO and Dyl2) were the dominant components. Subunit Axl and subunits encoded at Glu-B1 locus (Bx7, By8 and By9) were the minor ones. The proportion of subunit Dx5 depends on presence of subunit Ax1. When subunit Axl was present (1 7+9 5+10) the proportion of subunit Dx5 was approximately 50% reduced. The positive correlation between the relative amounts of the y-type HMW glutenin subunits and extensographic resistance and energy of dough, loaf volumes and appearance of bread (h/d) was found. That indicates that the y-type HMW glutenin subunits are more important for bread-making quality of investigated cultivars than the x-type. This investigation has indicated that the presence of HMW glutenin subunit 1 and both the presence and proportion of subunits 5+10 contributes to very good and good bread-making quality, while good bread-making quality of cultivars with subunits N 7+8(9) 2+12 is due to higher proportion of subunits at Glu-D 1 locus.