Abstract
D.Sc. (Botany)
Some physiological, biochemical and cytological changes
which occur and can induce wilting of the perianth leaves of
gladiolus flowers during the postharvest period was studied.
The basal floret of a commercial cut gladiolus inflorescence
is normally at a more advanced stage of development than the
others on the same inflorescence and the extent of development of the different buds decreases progressively from the
basal to the terminal floret. The terminal florets on a cut
inflorescence contain inadequate intracellular respirable
reserves and will not develop fully unless certain nutrients
are taken up from the vase medium. Wilting of the perianth
leaves of cut inflorescences occurs even when the percentage
moisture in the flower tissue is still relatively high.
This indicates that the loss of moisture by transpiration is
not the only factor responsible for apparent wilting. The
respiration rate, moisture content, pectic substances present and pectin methyl esterase (PME) activity, ion leaching
and the percentage apparent free space (%AFS) were, therefore, compared with the ultrastructural changes that occur
to elucidate their contribution towards wilting.