Abstract:
In carnations more than in any other flowers, understanding of the physiology of flower senescence and development of practical techniques for postharvest handling have advanced in recent years.
Three important practical developments have already been commercially applied:
- Postharvest pulsing with STS - this blocks ethylene action and greatly extends flower longevity.
- Treatment with sugar-rich solutions - this promotes full opening of flower buds in spray carnations and enables opening of standard carnations cut when buds are still tightly closed.
- Long-term storage of both standard and spray carnations.
A better understanding of the physiology of senescence in carnation flowers has been achieved, especially with regard to the following aspects:
- Elucidation of the sites of activity involved in the various steps of ethylene biosynthesis and metabolism in different parts of the flower, and the role of other hormones (cytokinins, auxins and abscisic acid) in influencing the sensitivity to ethylene and the regulation of ethylene biosynthesis.
- Changes in biophysical and biochemical properties of petal membranes during the aging process, in relation to ethylene and water stress.
- The role of interaction between the various parts of the carnation flower in controlling senescence.
- Changes in proteins and mRNAs during senescence, indicating control at the level of gene expression.
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