Diversity of flower colours in Rhododendron simsii Planch. and prospects for breeding

Summary A survey of the flower colours present in evergreen azaleas, Rhododendron simsii Planch is given. The following colours occur: white, red, carmine red, pink, purple and lilac. Crosses can lead to greater diversity although no really new shades have resulted. Quantitative anthocyanin and flavonol determinations for the cultivars enable us to gain an insight into the possiblities of increasing these contents and thus obtaining new colours. The prospects of breeding for intensely red, yellow and blue cultivars are also reviewed.