Effect of spermidine on the quality of vase-inserted Paeonia suffruticosa ‘Luoyang Hong’

Abstract

Vase-inserted cut tree peony flowers have a short viewing period and research focusing on prolonging the flowering duration is limited. This study investigated the effects of spermidine (Spd) on tree peony cut flowers inserted in vases containing different concentrations of Spd solutions. Paeonia suffruticosa ‘Luoyang Hong’ cut flowers at the full blooming stage were used as the test material, and floral aroma, phenotypic characteristics, and physiological indices were selected as the evaluation indicators. The results indicated that a concentration of 400 μmol·L⁻¹ Spd significantly increased the contents of terpenoids, ketones, and alcohols, while 5 μmol·L⁻¹ Spd significantly elevated the levels of hydrocarbons and benzene. The aldehyde content in the vase-inserted tree peony cut flowers was significantly enhanced after the addition of 300 μmol·L⁻¹ Spd. Moreover, 5 μmol·L⁻¹ Spd significantly improved the fresh weight, flower diameter, and flower height, prolonged the flowering period, increased the superoxide dismutase, peroxidase activities, and soluble protein content, and decreased the activities of ACC oxidase, ACC synthetase, and malondialdehyde (MDA). In conclusion, the addition of 5 μmol·L⁻¹ Spd effectively enhanced the contents of floral phenylcyclic compounds, maintained the ornamental quality, and delayed the senescence of vase-inserted cut tree peony flowers.