Genetic Linkage Map of Glu-D1 and Allelic Variation of HMW Glutenin Subunits in Some Iranian Bread Wheat genotypes

High-molecular weight (HMW) glutenin subunits are encoded by the Glu-1 loci (Glu-A1, Glu-B1 and Glu-D1 ) on the long arms of chromosomes 1A, 1B and 1D. In the present study, we constructed genetic linkage map of Glu-D1 and then investigated the allelic variation of HMW glutenin subunits at Glu-A1 and Glu-D1 gene loci in 30 Iranian genotypes using Functional markers. Glu-D1 was located at 50.8 cM on chromosome 1D and it was tightly linked to wPt-3743 marker (>1 cM). QTL analysis using composite interval mapping detected one significant QTL for grain yield (GY) on chromosome 1D. This QTL (QYld.abrii-1D) was located between wPt-3743 and Glu-D1 gene locus. Allelic variation of HMW glutenin subunits showed the most frequent alleles were the null allele at Glu-A1 and Dx2+Dy12 alleles at Glu-D1loci. The frequency of Null alleles or 1 and 2* were 40% and 60% respectively. Only 9 genotypes included allelic combination of Dx5+ Dy10 and the rest of genotypes had Dx2+Dy12 in the Glu-D1 locus. According to the Nei's genetic diversity index, alleles at Glu-A1 locus have more dispersion in genotypes compared to Glu-D1 locus. The cluster analysis of data based on the Simple Matching coefficient and UPGMC methods, classified the genotypes into four groups. Six genotypes including: Bezostaya, Tajan, Navid, Karaj1, Neyshabour, and Golestan had Ax2* and Dx5+ Dy10 subunits at Glu-A1 and Glu-D1 gene loci. Identification of genotypes with suitable allelic combinations can be used in breeding programs, especially in hybridization.