Relationship between Improvement of the Baking Quality and Down-Regulation of Dx2 and Dy12 Genes in Mutant Bread Wheat

In current research, the expression level of Dx2 and Dy12 genes on Glu-D1 locus that encoding the high-molecular-weight glutenin subunits (HMW-GSs), with negative impact on quality of bakery in genotype mutant bread wheat called RO-3 with high quality of bakery and its parent (Roshan) with low quality of bakery was investigated. For this purpose, sampling was performed grains at intervals of 5, 10, 15, 20 and 30 days post-anthesis (DPA). The gene expression results showed that RO-3 genotype had the highest gene expression decreasing for Dy12 genes at 5 DPA compared to parental genotype, and for Dx2 gene the highest gene expression decreasing was 10 DPA compared to parental genotype. Generally, during seed development both genes in mutant genotype had gene expression decreasing than the parental genotype. The most dry weight accumulation rates occurred in 10 to 15 DPA in mutant genotype. So, the early stages of seed development for reducing the expression of these genes and rates dry weight accumulation is critical in mutant genotype. The grain-filling rate and the maximum grain weight were higher in mutant genotype than the parental genotype. Therefore breeding the cultivars with higher grain filling rate and also selection of varieties with low expression for Dx2 and Dy12 genes play important role in the selection of varieties with high yield and quality of bakery.