Cut leaves of Zantedeschia aethiopica and Z. elliottiana are widely used as the florists’green. Over the years we studied the parameters related to postharvest quality of leaves in the two above species. Here the effect of plant hormones known to delay leaf senescence (benzyladenine and gibberellic acid) and of the standard preservative solution (8-HQC + 2% sucrose) on the reducing sugars contents is presented. BA (0.1 mmol·dm^-3) and GA₃ (0.25 mmol·dm^-3) were applied as 24  h pulse treatments. Pulsed and unpulsed leaves were kept either in water or in the preservative. In both species contents of reducing sugars during their senescence in vases initially rose and then dropped to 60–80% of the initial levels. Pretreatment with BA did not counteract a decrease in reducing sugar contents while in the GA₃-treated leaves sugar loss was prevented in Z. aethiopica and a  20% increase occurred in Z. elliottiana. Placing leaves in the sugar containing solution provoked a dramatic loss of reducing sugars in Z. aethiopica (to 12% of the initial level) while in Z. elliottiana this loss was less pronounced (52% of the initial value). Cytokinin did not mitigate the negative effect of the preservative on reducing sugar losses while GA₃ was more effective in this respect. Results of analyses do not support hypothesis that sugar depletion might be a cause of senescence of detached leaves in the two Zantedeschia species.

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