Abscisic acid analogue effects on the vase life and leaf crisping of cut Baccara roses

The plant growth regulator abscisic acid induces stomatal closure, which can reduce transpiration rate and extend vase life of cut flowers by maintaining a positive water balance. Analytical-reagent grade abscisic acid is, however, expensive. In this work, the effects of 2 potentially inexpensive synthetic analogues of abscisic acid were studied as to their effects on cut Baccara roses. Abscisic acid and its analogues PBI-365 and PBI-429 reduced transpiration and helped to increase fresh weight during the first few days of vase life. However, the reduction in transpiration rate brought about by abscisic acid and the analogues did not alter vase life. Sucrose in the vase solution at concentrations of 2 and 4% increased vase life of cut Baccara roses. However, the highest sucrose concentration (4%) caused leaf crisping, thereby reducing the quality of the flower stems. Abscisic acid and the analogue PBI-365 reduced this phytotoxicity by induction of stomatal closure and reduction of vase solution sucrose flux into the leaves.