Molecular characterization and marker development of a novel soft wheat high-molecular-weight glutenin subunit 1Dy12₁...

High-molecular-weight glutenin subunits (HMW-GSs) are the major determinants of gluten strength and dough elasticity, as well as wheat end use quality. A novel HMW-GS 1Dy12₁ in soft wheat is associated with low protein content, weak gluten and superior cookie-baking quality, but lacks a simple and effective genetic marker to distinguish it from other 1Dy alleles.

The subunit 1Dy12₁ allele was cloned for the first time from eastern USA soft winter wheat. Molecular characterization of the 1Dy12₁ subunit showed a coding nucleotide sequence of 2022 bp, which is 39 bp longer than the 1Dy12 subunit. The 1Dy12₁ subunit spanned 673 amino acid residues with a similar molecular structure to other published y-type subunits at the Glu-D1 locus. Known y-type subunits at the Glu-D1 locus have seven cysteine residues at conserved positions in the repetitive domain. Subunit 1Dy12₁ had an extra cysteine residue in the repetitive domain as a result of an adenine to guanine transition. A kompetitive allele-specific polymerase chain reaction (KASP) marker for identifying the 1Dy12₁ allele was developed and validated using 32 eastern soft winter wheat varieties with either the 1Dy12 or 1Dy12₁ allele. The new KASP marker effectively distinguished varieties with subunit 1Dy12₁ from subunit 1Dy12. The marker also distinguished nine varieties with subunit 1Dy10 better suited to bread baking at the Glu-D locus from subunit 1Dy12₁ varieties.

The new KASP marker is an effective tool to efficiently identify soft wheat varieties or breeding lines carrying HMW-GS 1Dy12₁ for superior cookie-baking quality. © 2026 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.