The color of the petals of two cultivars ofFuchsiawhich exhibit a color change with age was studied with respect to the pigments present and the pH of the cell sap at various stages of development. In both varieties, malvidin 3,5-diglucoside appeared to be the dominant pigment, with peonidin 3,5-diglucoside as a minor component. There appeared to be no change in the pigments themselves with age, although the color ranged from a blue in young flowers to a magenta in old flowers. This color change was correlated with a drop in pH from about 5.5 in young blue flowers to about 4.0 in old flowers, a drop which seemed to occur abruptly about the time of pollen release. The operation of a copigmentation effect was confirmed, and the presence of a copigment in addition to quercitin glucosides is suggested.
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