Evaluation of Hexaploid Wheat Varieties for Making Bread by High Molecular Weight (HMW) and Low Molecular Weight (LMW) Analysis

Knowledge of composition of high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS) and their associations with bread making and quality will contribute to genetically improving processing quality of bread wheats in Iraq. Six bread wheat varieties (Tammuz, Aras, Rabia, Cham 4, Cham 6 and Costantino) were conducted to detect the allelic variation at Glu-1 and Glu-3 loci by SDS-PAGE electrophoresis and to understand their effects on dough properties. Important methods applied for the breeding of bread-quality wheat (Triticum aestivum L.) consist of small-scale bread-quality tests for the determination of the grain protein content, SDS-sedimentation volume, thousand kernel weight and kernel diameter. The thousand kernel weight and SDS-sedimentation volume showed relatively higher significant among the varieties, whereas the flour yield showed no significance difference. The results of SDS-PAGE indicate that subunits/alleles 1 and null at Glu-A1, 7, 20 and 7+9 at Glu-B1, 2+12 and 5+10 at Glu-D1, allele a at Glu-A3, alleles d and m at Glu-B3 and alleles j and k at Glu-D3 in bread wheat varieties. The lowest frequency of subunit 7+9 was found in variety Tammuz. On the other hand, the variety Tammuz showed the highest value of score quality and the varieties Cham 4 and Cham 6 had the lowest value of score quality. Genetic diversity of wheat was evaluated by constructing the dendrogram for high molecular weight (HMW) and low molecular weight (LMW) gluten subunit bands.