Relationship between HMW-GS bands and bread making quality traits in recombinant inbred lines derived from a cross between Zagros and Norstar wheat varieties

Nowadays, many breeding programs of wheat focus on improving bread making quality. Therefore, at first, existent genetic variation in three loci Glu-A1, Glu-B1 and Glu-D1 was studied among 28 recombinant inbred lines (RILs) derived from a cross between Zagros and Norstar wheat varieties and 10 commercial wheat varieties via SDS-PAGE. Then, relationships between the bands and bread making quality traits such as macro-polymeric gluten content, grain moisture percentage, Zeleni sedimentation volume, grain weight, SDS sedimentation volume, grain hardiness, hectoliter weight, water absorbance percentage, gluten index, protein percentage, bread volume and wet gluten were studied via multiple linear regression. According to analysis of molecular variance (AMOVA), a considerable variation was obtained within two groups, RILs and commercial varieties, as same as between them. Based on regression analysis, alleles from the Glu-A1 locus especially allele 1 had the most relationship with bread making quality traits, so that this allele was positively related to protein percentage, Zeleni sedimentation volume, SDS sedimentation volume, gluten index, macro-polymeric gluten content and negatively with wet gluten. Allele 2* from the mentioned locus had positive relationship with grain weight, Zeleni sedimentation volume and negative with grain moisture percentage. Null allele from the Glu-A1 locus was negatively related to protein percentage and positively to grain weight. Allele 2 from the Glu-D1 locus indicated positive relationship with macro-polymeric gluten content and negative with bread volume. The results of this research showed that most important allele affecting the bread making quality traits was allele 1 from the Glu-A1 locus which had a negative significant relationship with the wet gluten and positive with the protein percentage, Zeleni sedimentation volume, gluten index and SDS sedimentation volume. The practical significance of these results is the ability to quickly and appropriately select the genotypes in the early generations of breeding programs.