INTERRELATIONSHIP OF SEVERAL PHYTOHORMONES IN THE REGULATION OF ROSE PETAL SENESCENCE
Two rose cultivars were chosen as models for the study; a short-lived cultivar ('Dr. Verhage'='Golden Wave') and a long-lived one ('Lovita'). Senescence processes of rose petals are controlled by at least three phytohormones: cytokinins, ethylene and abscisic acid (ABA). The endogenous level of cytokinins declines with age and is lower in the short-lived cultivar. Ethylene evolution rises in the initial stage of petal senescence, and is higher in the short-lived cultivar. ABA level rises at the latter stage of petal senescence, and is higher in the short-lived cultivar. Extrenal application of cytokinin delays senes cence. Ethylene induces a rise in endogenous ABA level. Water stress hastens senescence of cut flowers. Kinetin improves water balance of flowers by promoting water absorption. ABA delays senescence of leafy flowers by improving their water balance under stress conditions.
Halevy, A.H. and Mayak, S. (1975). INTERRELATIONSHIP OF SEVERAL PHYTOHORMONES IN THE REGULATION OF ROSE PETAL SENESCENCE. Acta Hortic. 41, 103-116