Rose flowers (Rosa hybrida L.) are highly perishable and have a limited vase life. This study evaluated the effects of preharvest foliar applications of γ-aminobutyric acid (GABA) and calcium chloride (CaCl2), individually and combined, on antioxidant responses and vase life of cut Jumilia rose flowers. Treatments included foliar sprays of GABA at 0, 20, 40, and 60 mM and CaCl2 at 0, 0.75%, and 1.5%, applied in a factorial design within a completely randomized setup before harvest. Results showed GABA and CaCl2 interaction (especially, 60 mM GABA and 1.5% CaCl2) significantly increased enzymatic antioxidants including superoxide dismutase, catalase, and peroxidase, as well as non-enzymatic antioxidants such as flavonoids, carotenoids, phenolics, and antioxidant activity in petals compared to control. SOD activity in roses, treated with CaCl2 (1.5%) and GABA (60 mM), peaked at 7.86 units. mg−1 protein min−1, showing a nearly 2.93-fold increase over the control (2.68 units. mg−1 protein min−1). A parallel trend was observed for CAT activity. These treatments also reduced petal malondialdehyde content and polyphenol oxidase activity. Protein content and vase life duration increased in all treatments. Plants treated with a combination of GABA (20 mM) and CaCl2 (0.75%), GABA (60 mM) and CaCl2 (1.5%), or GABA (40 mM) individually exhibited the longest vase life duration. The co-application of GABA and CaCl2 improved the antioxidant activity and postharvest quality of cut roses by reducing PPO activity and MDA contents, increasing protein content and prolonging vase life. This treatment is a potential postharvest strategy to improve antioxidant capacity and delay senescence in cut roses.
Teucrium polium has been used to treat gastrointestinal disorders, inflammation, diabetes and rheumatism. This plant has beneficial therapeutic properties. In this research the changes in the composition of essential oils from the aerial parts of Teucrium polium were determined at different temperatures and times. The essential oil of air-dried samples was obtained by hydro distillation and analyzed by gas chromatography/mass spectrometry (GC/MS). Changes in essential oils compositions were detected during storage for 3 months in refrigerator, freezer, and at room temperature. The results indicated that at room temperature, the proportions of the compounds with lower boiling temperatures such as Cis-Verbenol (2.11-1.78%) and Germacrene D (1.56-0.94%) were decreased significantly. Furthermore, the essential oil composition showed the least alterations and Teucrium polium L. kept its primary quality when stored at low temperatures, particularly in refrigerator and freezer (Except: α-Pinene, β-Pinene and Limonene).