Seed coat colour in adzuki bean is an important quality trait and closely associated with anthocyanin metabolism pathways. To further understand the inheritance of seed coat colour pattern, the inheritance between multiple seed coat colours and ivory seed were analysed using F1:2, F2:3 and F3:4 populations derived from five bi-parental crosses. The differences between ivory and red mottle on ivory are controlled by a single recessive R locus and RI locus, respectively. Green, light brown and golden are all dominant to red and governed by two loci. The B (brown) locus shows dominant epistasis over T locus. The R (red) locus was recessive epistasis to B (black), T (light brown), G (golden), GR (green) and RI (red mottle on ivory) loci. The new insight into the strong recessive epistasis of the R locus will be important for gene mapping and cloning, candidate gene functional validation and quality improvement in adzuki bean.
