Associations between high molecular weight glutenin subunits with bread quality traits of some bread wheat cultivars

To evaluate the variations of high molecular weight glutenin subunits (HMW-Gs) at the Glu-1 loci and the relationship between different allelic combinations with grain quality traits, 25 bread wheat varieties were assessed using SDS-PAGE method in the University of Birjand, in 2013. In this study, a total of 14 alleles and nine allelic combinations were detected. At the Glu-A1 locus, frequency of subunit 2*, Null allele and subunit 1 were 52, 36 and 12 percent, respectively. At the Glu B1 locus, the most frequent allelic combination was 7+8 with 40% and 13+16 allelic combination was the lowest with eight percent. At the Glu-D1 locus, 40% of genotypes showed 5+10 allelic combination and the other 60% showed 2+12 allelic combination. Overall score average based on the quality of bread wheat glutenin subunits was 7.76 out of 10, which is relatively good in quality. In this study, Kukri, Gladious and Excalibur (Australian bread wheat cultivars), Verinak and Zarrin with the overall score of 10 were the best in quality based on allelic combinations at the HMW-Gs loci. Alamoot and Hamoon showed the lowest quality score of five were considered as poor quality wheat cultivars. Based on the results of analysis of variance and stepwise regression analysis, subunit 1, 13+16 and 5+10 subunits had a positive effect on grain protein content. For SDS sedimentation volume, 5+10 subunits had the positive effect, while 2* allele and 7+9 subunits had the negative effect on this trait. Given the important role of HMW-Gs as genetic markers for bread making and flour quality, the results of this study is a genetic estimation of the Iranian and Australian bread wheat cultivars for their quality characteristics.