Abstract
TThe present study investigates the roles of nitroprusside (SNP), salicylic acid (SA), methyl jasmonate (MJ), and their interaction with 8-hydroxyquinoline sulfate (8-HQS) in regulating the peroxidase activity (POX), water uptake, the relative water content (RWC), the contents of malondialdehyde (MDA), soluble sugar, proline, and protein content in the petals and the stem bending of Gerbera jamesonii ‘Sun Spot’ cut flowers. Cut flowers were treated with various concentrations (50, 100, and 200 µM) of hold-solutions containing 8-HQS, SA, MJ, and SNP. Hold solutions were used alone or in combination with 100 µM 8-HQS for 24 h. Distilled water was used as control and sucrose (4%, w/v) was added to all solutions. The findings showed that 50 µM SA+ 100 µM 8-HQS markedly improved the RWC, the contents of proline, anthocyanin, carotenoid, protein, and soluble sugar, and activities of POX in the petals and markedly reduced water loss and the contents of MDA in the petals, compared with other treatments, especially the control. Meanwhile, the combination of plant growth regulators (PGR) with 8-HQS markedly improved positive indexes than use alone PGR. This phenomenon seemed to be due to more absorption of PGR. Among different concentrations of PGR, 50 μM is the most effective treatment for the improvement of the vase life of Gerbera jamesonii cut flowers. The results also demonstrated that SA+8-HQS improves the vase life of gerbera cut flowers by enhancing the membrane stability and water retaining capacity as well as increasing proline, antioxidant activity, and pigment contents.
