Development of PCR-based markers for the identification of wheat HMW glutenin subunit alleles at the GLU-A1 and GLU-D1 loci

The allelic variations of high-molecular-weight glutenin subunit locus in common wheat (Triticum aestivum L.) markedly influence grain end-use quality. GLU-A1, GLU-B1, and GLU-D1, which encode high-molecular-weight glutenin subunits, are located on the long arms of chromosomes 1A, 1B, and 1D, respectively. However, existing markers for distinguishing alleles at the GLU-A1 and GLU-D1 are limited with regard to both number and resolution. In the present study, we enhanced the utility of PCR-based allele detection by developing seven new agarose gel-based markers capable of differentiating four Glu-A1x, four Glu-D1x, and two Glu-D1y alleles. These new markers, in combination with previously published PCR markers, were used to successfully identify the Glu-A1 × 1, Glu-A1 x 2*, Glu-A1 x 2.1*, and Glu-A1x-null alleles and the Glu-D1 x 5, Glu-D1 x 2, Glu-D1 x 2.1, and Glu-D1 x 2.2 alleles across 25 wheat resources. Additionally, we developed a novel marker that enables us to distinguish between the Glu-D1y10 and Glu-D1y12 alleles more clearly than conventional markers. These improved PCR markers represent a reliable and efficient tool for detecting allelic variations at the GLU-A1 and GLU-D1 loci. They are expected to serve as valuable resources for marker-assisted selection and marker-assisted backcrossing aimed at improving the processing quality of wheat.