The study analyzed the gluten proteins in 33 wheat varieties grown in Ningxia over the past 50 years. They found a variety of gluten subunits in these cultivars, with some showing high-quality subunits like 5+10 and 17+18. The overall quality score of the wheat cultivars ranged from 5 to 10, with an average of 8.2. While the quality score increased slowly over time, the frequency of high-quality subunits like 5+10 also increased. This information can be used to improve the quality of wheat through breeding programs.