Distribution of carotenoids in the flower of non-yellow commercial petunia

The carotenoid contents of the flowers of 35 commercial petunia cultivars having non-yellow flowers (non-yellow cultivars) were compared with those of five cultivars having yellow flowers (yellow cultivars). All yellow cultivars were confirmed to contain large quantity of carotenoids such as b-carotene, lutein, zeaxanthin as well as unknown carotenoids. The carotenoid content in `Summer Sunʹ was prominent and seemed to be rather exceptional among yellow cultivars examined. Carotenoid contents in the flowers of several cultivars having red colour, such as `Celebrity Redʹ and `Celebrity Red Mornʹ, and other colours, such as `Baccara Burgundy Picoteeʹ, were revealed to be comparable with those of yellow cultivars except `Summer Sunʹ. The existence of considerable amount of carotenoid in the flower was also detected by direct measurement of absorbance spectra for the fresh flower. The possible involvement of carotenoid in the floral colour of garden petunia, as an additional element, is discussed.