Effects of ethylene and cytokinins on vase life of cut Eucalyptus parvifolia Cambage branches

The role of ethylene and cytokinins was investigated during postharvest senescence of cut Eucalyptus parvifolia Cambage branches. The effect of endogenous and exogenous ethylene on the vase life of the cut branches was studied using 2 mM 1-aminocyclopropane-1-carboxylic acid (ACC) as a continuous treatment or “pulse” treatment for 48 h with 20, 40 and 80 l l−1 ethylene. Both endogenous and exogenous ethylene reduced the vase life of the branches; however, the effect of the endogenous hormone was stronger than the exogenous applications. Ethylene biosynthesis was inhibited by pulse treatment for 24 h using 1 mM AOA or 2 mM CoCl2. The latter treatment significantly extended the vase life of the branches by delaying senescence. The effect of cytokinins was evaluated on the vase life of cut E. parvifolia branches by pulse treatment for 24 h with 10, 50 and 100 mM thidiazuron (TDZ) or 85, 130 and 260 mM N6-benzyladenine (BA). The results obtained showed that no response was observed following pulse treatment with BA while, although TDZ had little effect on vase life, it was a good inhibitor of chlorophyll degradation.