ASSOCIATION BETWEEN HIGH-MOLECULAR-WEIGHT SUBUNIT GENOTYPES OF SEED STORAGE GLUTENIN AND AGRONOMIC TRAITS IN A DOUBLED HAPLOID POPULATION OF BREAD WHEAT

The association between high-molecular weight (HMW) subunit alleles of glutenin and agronomic traits was examined in 52 doubled haploid (DH) lines produced from an F1 hybrid (Chinese Spring x Norin 61) of bread wheat by the bulbosum technique. In addition, the effect of gibberell in (GA)-insensitive semi-dwarfing alleles involved in these DH lines w as assessed. The identified alleles coding for the HMW subunits of glu tenin were Glu-A1c and Glu-D1a in Chinese Spring and Glu-A1b and Glu-D 1f in Norin 61. The DH lines were grouped into the four genotypes reco mbinated at the two HMW subunit loci. No significant difference was fo und in grain hardness among the genotypes. Only the lines of the recom binant genotype Glu-A1c.Glu-D1f expressed delayed heading time and tal ler plant height than those with the other three genotypes. On the oth er hand, Norin 61 carried the allele Gai/Rht2 for GA-insensitivity whe reas Chinese Spring was GA-sensitive. The DH lines were grouped into t wo genotypes at the Gai/Rht2 locus. The lines of the Gai/Rht2 genotype were significantly shorter in plant height and higher in grain yield than those of the gai/rht2 genotype. The combined effect of Glu-A1c an d Glu-D1f in extending plant height almost nullified the effects of Ga i/Rht2 in reducing plant height. These results suggest that the select ion for glutenin lici remarkably affects the expression of certain agr onomic traits in bread wheat.