THE ROLE OF BACTERIAL METABOLITE(S) IN AFFECTING WATER UP= TAKE BY CARNATION FLOWERS. (+)

Four different bacterial species were found growing in large numbers in the holding solution of cut carnations ‘Siva’: they were isolated and cultured on an artificial medium and on sterilized carnation stems.
The effect of metabolite(s) produced in vitro by these bacteria was tested on longevity of cut carnations, on water saturation deficit, on water flow resistance and on the appearance of necrosis on petals.
Large differences were observed among the different bacteria.
The metabolite(s) produced by two bacteria reduced significantly the longevity of cut flowers, increasing significantly the water flow resistance measured in the basal part of the stem and the water saturation deficit in the petals of flowers.

No significant effect was observed when the metabolite(s) were tested by evaluating their direct effect on petals.
These experiments confirm that the effects of bacteria on decreasing longevity of carnation flowers are not only due to the microorganism themselves, but also to the toxic metabolite(s) they produce which are released into the holding water and absorbed by the stems.
These bacterial metabolite(s) block the xylem vessels impairing water balance and causing wilting of the flowers.

II International Symposium on Post-harvest Physiology of Cut Flowers

E. Accati, S. Hayak, I. Abbattista Gentile

https://doi.org/10.17660/ActaHortic.1981.113.18