Substitution mapping of QTLs controlling SPAD value and SLA of flag leaves at heading stage on the long arm of chromosome 4 based on 13 F3-derived lines. (left) Graphical genotypes. Black denotes regions homozygous for Habataki alleles; white denotes regions homozygous for Sasanishiki alleles. The candidate QTL region is indicated by a double-headed arrow. (right) SPAD values and SLA values. Bars indicate means and error bars indicate SD. Black indicates a significant difference from Sasanishiki at the 1% level by Dunnett’s test.