ISHS Acta Horticulturae 138: Postharvest Physiology and Storage, XXI IHC
POSTHARVEST PHYSIOLOGY OF MEDITERRANEAN CARNATIONS:PARTIAL CHARACTERIZATION OF A BACTERIAL METABOLITE INDUCING WILT OF FLOWERS. |
| Author: | E. Garibaldi |
| Abstract:
Maintenance of optimal water balance has been considered the most important factor in extending the life of cut flowers. Increasing resistance to water flow in vascular tissue is recognized to be a major cause of water stress in cut flowers. Wilting of carnation cut flowers is probably not only caused by microbial population developing in the holding solution but also by metabolites produced by bacteria released into the water and moving up to the stem and perhaps to the flowers. These bacterial metabolites block the xylem vessels impairing water flux and resulting in wilting of the flowers. The aim of this research was to ascertain the nature of the metabolite(s) produced by a bacterium isolated from holding water of cut carnation flowers in presence or absence of carnation stems. The culture filtrates of a bacterium grown on a artificial medium contain a metabolite causing a strong reduction of the water flux through carnation stems. A strong correlation was observed between growth of the bacterium and reduction of water flux caused by the metabolite which is preferentially produced when the bacterium is grown at pH around neutrality. This metabolite was partially characterized: it is not dializable, is partially destroyed by autoclaving and it has a molecular weight around 12,000. | |
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