Classification of the Indian cultivars carrying Hwa1-1 or Hwa2-1 gene and 13 reference cultivars into four varietal groups based on banding patterns of 39 DNA markers covering all 12 rice chromosomes. DNA markers with an asterisk (*) were developed by RGP (http://rgp.dna.affrc.go.jp/E/publicdata/caps/index.html); those without an asterisk were developed in this study (Table 2). The same banding patterns as Nipponbare are indicated as solid rectangles. Other patterns are shown as open and shaded rectangles. Shown above are genetic relations among the 16 cultivars obtained using UPGMA cluster analysis. Each fragment size of the 39 markers was treated as a unique characteristic and scored as present (1) or absent (0). The data matrix was used to calculate genetic similarities using the Jaccard (1908) coefficient.