Melatonin pulse treatment for cut roses

Cut roses (Rosa hybrida L. cv. Samurai) undergo rapid postharvest senescence, limiting vase life and quality.

This study evaluated melatonin's efficacy as a biostimulant, applied via pulse (30-min immersion) or continuous (vase solution) methods at 0.1 mM and 1 mM concentrations, in a completely randomized design with three replicates of 10 stems per treatment. 

All treatments were applied immediately after stem preparation. For pulse treatments, stems were immersed up to 10 cm from the base in melatonin solutions (0.1 or 1 mM) for 30 minutes at 20°C in the dark, then rinsed with distilled water and transferred to vases with fresh distilled water, refreshed every 48 hours. For continuous treatments, stems were placed in vases with melatonininfused solutions (0.1 or 1 mM), replaced every 48 hours to maintain concentration. 

To prevent melatonin degradation under light, all vases were covered with opaque material [19]. 

Vases were maintained at 20 ± 2°C, 60–70% relative humidity, and a 12-hour photoperiod (15–20 μmol m⁻²
s⁻¹ PPFD). Each treatment had three replicates of 10 stems (one per vase).

Assessed parameters included vase life, flower quality, diameter, chlorophyll and anthocyanin contents, electrolyte leakage, relative water content, solution uptake, and antioxidant enzyme activities.

Results

The 0.1 mM pulse treatment extended vase life by 61% (9.67 vs. 6.00 days), improved flower quality (5.00 vs. 3.33), increased diameter by 18% (51.00 vs. 43.33 mm), enhanced chlorophyll by 22% and anthocyanin by 36%, and reduced electrolyte leakage by 43%, with correlations to base life (r = 0.71–0.94, P < 0.001).

The 0.1 mM continuous treatment was less effective, and 1 mM concentrations showed minimal benefits

Conclusion

Melatonin's antioxidant and anti-senescence properties provide a sustainable, cost-effective strategy for extending rose vase life, with 0.1 mM pulse application as the most effective method for commercial floriculture.

Sources

Optimizing Melatonin Pulse Treatment for Enhanced Postharvest Vase Life and Quality in Cut Roses
(Rosa hybrida cv. Samurai)
Sara Shamsinejad, Shahid Bahonar, Vahid Reza Saffari
Research Square
DOI: https://doi.org/10.21203/rs.3.rs-7751050/v1