Abstract

The high molecular weight glutenin subunits (HMW-GS) are key factors in bread making quality since they are major contributors of glutenin elasticity and polymer formation of wheat dough. DNA markers for quality traits are currently used by wheat breeders for direct measurement of these traits without waiting for advancing generations of breeding materials to conduct biochemical tests. The goal of this study was to use DNA markers for screening newly developed Saudi wheat varieties for the presence of HMW-GS genes. Four new Saudi wheat lines (KSU 102, KSU 103, KSU 105 and KSU 106) and two American cultivars Yecora rojo and West Bread (popular in the Kingdom) were utilized in screening for the presence of the HMW-GS using primers covering the three wheat genomes. From the A genome, Ax2* was used.  While two sets of primer pairs were used in the B genome. One primer pair for the Bx7 allele and another primer pair for By8 allele. From the D genome, primer pairs for Dx2/Dx5 and another primer pair for Dy10/Dy12 were used. Our results showed that both KSU 102 and 106 were missing Ax2* in the Glu alleles A1 and contain the Dy12 in the Glu-D1 locus which is indication of the poor bread making quality. On the other hand KSU 103 and 105 contained subunit Ax2* as well as Dx5 and Dy10 indicates that these two varieties are of moderate bread making quality. In contrast, both West Bread and Yecora Rojo contained all the five genes indicating that these two cultivars are of good quality.

Key words: DNA markers, wheat varieties, high molecular weight glutenin, quality traits.