ISHS Acta Horticulturae 177: IV International Symposium on Flower Bulbs
STARCH METABOLISM IN FLOWERS OF SENESCING GLADIOLI INFLORESCENCES |
| Authors: | D.I. Ferreira, J.J. van der Merwe, G.H. de Swardt |
| Abstract:
Inflorescences of gladioli often fail to develop completely in a vase. To determine the cause of this phenomenon the relationship between changes in the starch concentration,  and  amylase activity and the respiration rate in senescing flowers of gladioli inflorescences were monitored.
In addition the uptake of (U14C) sucrose from a vase medium and its subsequent distribution through the gladioli inflorescences were also investigated.
The perianth leaves of senescing gladioli inflorescences showed a typical climateric pattern.
The initial high respiration rate immediately after picking coincided with a relative high starch concentration in the perianth leaves.
The starch concentration decreased rapidly during the post-harvest period.
Concomitantly both the The starch concentration of individual closed flower buds on the same inflorescence, decreased from the basal to the terminal floret. Basal florets contain sufficient carbohydrate reserves to ensure full development in contrast with the less developed terminal florets which will rarely develop completely. The accumulation of 14C sucrose absorbed from the vase medium was much higher in the terminal than in the basal florets, while the 14C activity was always low in the bracts. The low 14C activity indicates a lower sucrose demand. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
