Role of cytokinins in carnation flower senescence.
Stem and leaf tissues of carnation (Dianthus caryophyllus) plants appear to contain a natural antisenescence factor since removal of most of these tissues from cut carnation flowers hastened their senescence. However, kinetin (5-10 mug/ml) significantly delayed senescence of flowers with stem and leaf tissues removed. In addition, the life span of cut flowers with intact (30-cm) stems was increased with kinetin treatment. Peak ethylene production by presenescent flowers was reduced 55% or more with kinetin treatment and was delayed by 1 day. Kinetin-treated flowers were less responsive to applied ethylene (100 mul/l for 3 hours) than untreated flowers. Possible natural roles of cytokinins in carnation flower senescence are discussed.
Eisinger
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Department of Biology, University of Santa Clara, Santa Clara, California 95053.