Effect of different concentrations of sodium nitroprusside on physiological characteristics and the vase life of cut flowers of toberose (Polianthes tuberosa L.)

Polianthes (Polianthes tuberosa L.) is one of the most important cut flower worldwide and in Iran. A CRD-based factorial experiment was conducted to evaluate the effect of SNP on qualitative and quantitative parameters of this popular cut flower. Sodium nitroprusside was used at 1 and 10 µM along with control (distilled water). The highest vase-life was obtained with 1µm which increased vase-life for three extra days compared to control. The highest percent of floret opening was also gained in 1µM SNP. The percent of floret wilting, floret abscission, and stem weight reduction was also decreased at both concentrations of SNP. The lowest electrolyte leakage was found in 1µm SNP and this trait was decreased 1.5 times than control. The findings of the present research showed that vase-life was increased at both concentrations of SNP. Meanwhile, activity of antioxidant enzymes such as GPX and APX was increased at both concentrations but the activity of CAT was increased just at 1 µM. Furthermore, the activity of PPO and PAL enzymes was significantly decreased at both concentrations. Consequently, it appears that these compounds improved postharvest quality by reducing free radicals of oxygen, conserving membrane integrity, increasing the synthesis of phenolic compounds and decreasing the activity of PPO.