Association of Glutenin Subunits With Gliadin Composition and Grain Quality in Wheat

Abstract

The composition of high-molecular-weight (HMW) glutenin subunits was determined by sodium dodecyl sulfate (SDS) gel electrophoresis of grain proteins from a set of 98 wheats from many countries (17 from Australia) and a set of 78 wheats (mainly Australian) and one rye cultivar. Such SDS gel electrophoresis was shown to be a useful back-up to gel electrophoresis of the gliadin fraction for identifying Australian wheats. Associations between the glutenin subunits revealed by numerical analysis were interpreted to indicate genetic relationships between them. Associations were much stronger amongst glutenins or amongst gliadins than between members of the two protein classes. The HMW glutenin-subunit compositions of the Australian wheats were more strongly related to grain hardness than to dough strength, but both these relationships were mainly based on pedigree associations. Compared to the HMW glutenins, the composition of the gliadins was more closely related to dough strength, and this relationship was largely independent of pedigree.