When a cutoff value of 0.64 was used for genetic similarity among all varieties, three clusters were formed, I, II,and III (Figure 2), which contained 12, 7, and 3 varieties,
respectively.
The two Japanese cultivars, Koshihikari and Hitomebore, formed an independent subcluster, supporting the fact that Hitomebore was bred using Koshihikari as a parent.
Similarly, other varieties sharing parentage grouped in the same subclusters.