Abstract

Nitric oxide (NO) and  thidiazuron (TDZ) have been shown to extend the postharvest life of a range of flowers possibly by downregulating ethylene production. In this study, we have evaluated the effect of sodium nitroprusside (SNP), a nitric oxide donor and thidiazuron on postharvest senescence of cut Rosa flower. Therefore, we examined the effects of SNP and TDZ on its ethylene production  and shelf life. Flowers were treated for 24 h with 0, 20,40 µmol.L^-1 TDZ  and 0, 20, 40, 60 µmol L^-1 SNP and then held in the solution, 8-HQS at 300 ppm combination with 1% sucrose. Treatment with NO and TDZ delayed the ethylene production and prolonged shelf life. It was observed that, treating with NO and TDZ at a 40 µMol.L^-1concentration and 40 µM.L^-1 TDZ with 40 µM.L^-1 SNP decreased ethylene production  and senescence of floweres. SNP at 60 µMol.L^-1 harmed the flowers. It was suggested that NO and TDZ could decrease ethylene output, by inhibiting ACC synthase activity and reducing  ACC content.

Key words: Rose, nitric oxide, thidiazuron, ethylene biosynthesis, postharvest.