The researchers studied the high molecular weight glutenin subunits in OS winter wheat cultivars to see how they affect bread quality. They looked at 10 wheat cultivars and measured various quality parameters like protein content, dough properties, and baking results. They found that certain glutenin subunits were more common in the wheat cultivars, and that the Glu-D1 subunit was strongly linked to better bread quality. The Glu-1 quality score also had a positive relationship with dough properties and bread appearance. Overall, the study showed that specific glutenin subunits play a key role in determining the bread-making quality of wheat.