Association between High-Molecular Weight Subunit Genotypes of Seed Storage Glutenin and Agronomic Traits in a Doubled Haploid Population of Bread Wheat.

Abstract

The association between high-molecular weight (HMW) subunit alleles of glutenin and agronomic traits was examined in 52 doubled haploid (DH) Iines produced from an F1 hybrid (Chinese Spring x Norin 61) of bread wheat by the bulbosum technique. In addition, the effect of gibberellin (GA)-insensitive semi-dwarfing alleles involved in these DH Iines was assessed. The identified alleles coding for the HMW subunits of glutenin were Glu-Alc and Glu-Dla in Chinese Spring and Glu-Alb and Glu-Dlf in Norin 61. The DH Iines were grouped into the four genotypes recombinated at the two HMW subunit loci. No significant difference was found in grain hardness among the genotypes. Only the lines of the recombinant genotype Glu·Alc·Glu·Dlf expressed delayed heading time and taller plant height than those with the other three genotypes. On the other hand, Norin 61 carried the allele Gai/Rht2 for GA-insensitivity whereas Chinese Spring was GA-sensitive. The DH Iines were grouped into two genotypes at the Gai/Rht2 Iocus. 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-Alc and Glu-Dlf in extending plant height almost nullified the effects of Gai/Rht2 in reducing plant height. These results suggest that the selection for glutenin lici remarkably affects the expression of certain agronomic traits in bread wheat.