Carotenoid and Chlorophyll Accumulation in Flower Petals of Carnation

Carnation is one of the most important floricultural crops in the world. Over 20 wild species of Dianthus have been integrated during the long history of carnation breeding, and a wide range of petal colors, including red, yellow, orange, and white, have been developed. These flower colors are derived from quantitative and qualitative differences in flavonoid compounds. Wild Dianthus species expressing petal colors through carotenoids or chlorophylls have not been documented. In contrast, green-flowered and pale yellow-flowered carnation cultivars, which express their petal colors with these pigments, have been developed by conventional breeding. Such cultivars might be mutants that have lost the ability to avoid the accumulation of carotenoids and chlorophylls in the petals. In this section, based on our analysis of green- and pale yellow-flowered carnation cultivars, we discuss the possible mechanisms that regulate the accumulation of carotenoids and chlorophylls in carnation petals.