Rose is a top-cut flower in production, but due to improper flower opening, it faces heavy losses in postharvest handling. This study explores postharvest pulsing effects on the physiological changes that lead to flower opening and vase quality characteristics. Cut roses were treated with Sucrose (SUC), α-aminoisobutyric acid (AIB), and 8-hydro-quinoline citrate (8- HQC) under different combinations: CON; control, SUC; Sucrose, SUCA; SUC plus AIB, SUCH; SUC plus 8-HQC, AH; AIB plus 8-HQC, and SUCAH; SUCA Plus 8-HQC.  We examined the respiratory rate, stomatal conductance, and hydraulic conductance of flower stems, SUCAH, SUCA, SUCH, and AH showed positive feedback, while ethylene production was lowest compared to CON.   The flower opening percentages and speed were highest with more water uptake and flower diameter, and less microbial growth in SUCAH, followed by SUCA, SUCH, and AH than CON. Compared to CON, ethylene biosynthesis genes (RhACS2, RhACO1), and senescence-associated gene (RhSAG12) transcription were lowest, and the vase characteristics significantly improved in SUCAH, followed by AH, SUCH, and SUCA. Our results indicated that postharvest pulsing by SUCAH substantially affected the water and ethylene status, which led to flower opening and improved vase quality characteristics.

Index Terms- cut rose, ethylene, flower opening, vase life, sucrose, α-aminoisobutyric acid, 8-hydroquinoline citrate