Abstract
High quality bread is an important goal for wheat breeders. Glutenins, are considered key factors in improving bread quality, particularly HMW-GS, as they are the main contributors to bread quality. The HMW-GS are known to be encoded by six genes located at the Glu-1 loci on the log arms of chromosomes 1A, 1B and 1D. Sequence-specific primers were used to screen for HMW-GS genes within a collection of twenty nine local and elite spring bread wheat accessions adapted to irrigated agriculture. Eight gene-specific markers were used to screen for high-molecular-weight glutenin subunit (HMW-GS) genes to identify glutenin harboring alleles in each accession. The 29 genotypes showed eight different allelic combinations at the Glu A. Glu B and Glu D loci. Results showed that 26 genotypes carried the Ax1 allele and only 3 genotypes carried the Ax2 allele. At the B loci there were four different allelic combinations. The Bx7+By8 alleles were present in 6 genotypes, the Bx7*+By8 alleles were found in one genotype (Lang), the Bx7+By9 alleles were observed in 13 genotypes and the Bx17+By18 alleles were observed in 9 genotypes. At the D loci there were two allelic combinations. The Dx2+Dy12 were present in 14 genotypes while the Dx5+Dy10 were found in 15 genotypes. All the American varieties tested carried the Dx5+By10 alleles which were associated with excellent bread making quality (score of 10). The Australian lines had a very good bread making quality with an average 8.6, followed by CIMMYT varieties with an average score of 8.25. Many of the local Arabian lines lacked the favorable alleles DX5+Dy10 and had an average quality score of 8. The presence of HMW-GS in the tested genotypes were confirmed using PCR assay. The information generated in this study will be utilized in the breading program for parental selection and identification of new lines with high quality glutenin alleles.