Screening Bread Wheat Genotypes for High Molecular Weight Glutenin Subunits and Some Quality Parameters

Abstract

H igh Molecular Weight Glutenin Subunits (HMW - GS) composition s of 122 genotypes from bread wh eat crossing block were investigated in terms of some quality traits such as g rain Protein Content (PC), Sodium Dodecyl Sulphate (SDS), t he Particle Size Index (PSI), and Thousand Kernel Weight (TKW), by using SDS - PAGE. In total , 12 different HMW - GS combin ations were determined. Considerable diversity in terms of three Glu - A1 , Glu - B1 and Glu - D1 loci were identified. In Glu - A1 locus, 1/2*, 1 and 2* alleles were found with the frequency of 2.5, 12.3 and 85.5% , respectively . Whereas, in Glu - B1 , out of 7 report ed alleles, 7+8 (20.5%) and 17+18 (17.2%) were detected. Existence of 2 alleles at the locus Glu - D1 was revealed; in fact, 54.1% of them demonstrated the subunits 5+10 correlated with good bread making properties. The Glu - 1 score of genotypes ranged from 6 to 10. Among the genotypes, only 23 (18.9%) had 10 Glu - 1 quality score value. In the evaluation using the Genotype - Traits (GT) Biplot graph, PC and PSI were involved in section I while SDS sedimentation value and Glu - 1 score were involved in section II. O n the other hand, section III included the only TKW which was negatively associated with other traits. The desired genotypes can be used for the crossing programs to improve technological quality of bread wheat. Keywords : Biplot, HMW - GS, Landraces, Quality .