Researchers analyzed the grain quality of 16 keng rice cultivars in Shanghai. They found that improvements were made in milling and cooking qualities, but overall quality was lacking. Chalky grains negatively affected quality. The traits were grouped into 3 main components, explaining 90.166% of the variation. The cultivars were divided into 4 groups based on quality, with Group 1 being the best and suitable for hybrid breeding. Groups 2 and 3 had decent quality, while Group 4 was the worst and could be used for breeding better varieties. The genetic distance among cultivars in Shanghai was found to be narrow.