Genetic control of endosperm proteins in wheat : 2. Variation in high molecular weight glutenin and gliadin subunits of Triticum aestivum.

Endosperm protein subunits of 109 primitive and modern lines of hexaploid wheat, Triticum aestivum L. em. Thell., were fractionated by one-dimensional, high resolution, sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis (PAGE). A wide range of both qualitative and quantitative variation was observed in the fractions of the high molecular weight (HMW) glutenin and gliadin subunits of the different lines. The qualitative variation was expressed in the number of subunits per fraction and in their molecular weight, as determined by the differential rate of migration. The quantitative variation was expressed in the differential staining intensity of several subunits. The widest variation was detected in the HMW glutenin and gliadin subunits controlled by chromosome 1B while a much smaller variation was observed in those subunits controlled by chromosome 1A and further smaller variation in the subunits controlled by 1D. Only a small number of subunits in both fractions was found to be controlled by chromosome 1A indicating that diploidization of endosperm protein genes in common wheat has been non-random. The genetic and evolutionary implications of these findings are discussed.