Gluten proteins in wheat grains are generally considered one of the most important factors in determining dough properties and bread quality. In this study, wheat protein quality characteristics were investigated in 607 varieties collected from seven countries grown in a South Korean wheat breeding field for two years. The average protein content was 12.2±1.86%, and the sodium dodecyl sulfate-sediment volume (SDSS) was 46.9±8.39 mL. HI-LINE had the highest protein content (18.3±0.35%) and SDSS (76.7±1.98 mL), while both NE 84557 and Iksan 374 showed small deviations in protein content and SDSS. Protein content and SDSS values were higher in Ax2*+By8 and By9+Dy10 combinations at Glu-A, Glu-B1, and Glu-D1 loci of high molecular weight gluten subunit (HMW-GS) than in other combinations. However, no difference in Glu-A3 and Glu-B3 loci in LMW-GS was observed. Furthermore, in HMW-GS, the composition of Glu-D1 Dy10 and Dy12 had a greater effect on protein quality than Glu-B1 By8 and By9 when the allele of Glu-A1 had Ax2*. Significant differences were found between Dy10 and Dy12 genes of the HMW-GS Glu-D1 and between protein content and SDSS, but not among others. These results suggest that Glu-D1 is extremely important for improving protein quality in HMW-GSs. As a result of this study, HMW-GS allele selection using functional markers, protein content, and SDSS investigation are expected to enable the development of varieties with high protein quality that are stable amid various environmental changes.

A new winter wheat (Triticum aestivum L.) cultivar ‘Baekkang’ was developed by the National Institute of Crop Science (NICS) and Rular Development Administration (RDA) in 2015. Its heading date was April 23, and its maturity date was June 3, similar to that of ‘Keumkang’. ‘Baekkang’ had a shorter culm length (75 cm), longer spike length (8.0 cm), more spikes per m² (703), and more 1,000-grain weight (47.5 g) than those of ‘Keumkang’, which were 76 cm, 7.6 cm, 631, 46.4 g, respectively. ‘Baekkang’ was not a winter hardy crop and is susceptible to powdery mildew. However, it has moderate resistance to fusarium head blight. The average grain yield in the advanced yield trial was 5.5 MT/ha, 20% more than ‘Keumkang’. In the regional yield trial, this average yield was 5.1 MT/ha upland and 5.2 MT/ha in the paddy field, which were 10% and 18% more than that of ‘Keumkang’, respectively. Baekkang’s flour yield (71.2%) and flour lightness (92.40) showed similarities to those of ‘Jokyung’. ‘Baekkang’ also showed a higher protein content (12.4%), gluten content (10.1%), and SDS-sedimentation volume (60.0 ml). These results showed that the ‘Baekkang’ flour’s dough strength was greater than that of ‘Jokyung’. Baekkang’s high molecular weight gluten subunits composition was Glu-D1 (5+10), granule-bound starch synthase composition was Wx-A1 (a), Wx-B1 (a), and Wx-D1 (a), and puroindoline composition was Pina-D1(a) and Pinb-D1(b) (Registration No. 6966).