SENESCENCE AND SUGAR STATUS OF THE CUT FLOWER
The principal sugars in the corolla of the carnation are reducing sugars and sucrose; the former predominate at all stages of flower development. During senescence the total sugar declines until about half of the initial weight of reducing sugar remains at incipient wilting whereas sucrose practically disappears. In narcissus the ratio of the concentration of sugars depends on the stage at which the flower is cut. At the "goose-neck" stage, reducing sugars are present in smaller amounts than sucrose but during flower development and senescence, reducing sugars increase to a maximum, roughly coincident with full flower opening, and then decrease until half of the maximum remains at wilting; sucrose disappears as the reducing sugars increase.
Feeding carnation flower buds with sucrose causes an accumulation of reducing sugars in the petals and the life of the open flower is very nearly doubled; the same treatment applied to narcissus causes only a small improvement in longevity but results in substantial growth of the ovary. The findings lend support to the concept that the cut flower is a metabolically active centre and that complex translocation phenomena are involved during senescence.