Pulsing with Magnesium Oxide Nanoparticles Maintains Postharvest Quality of Cut Lotus Flowers (Nelumbo nucifera Gaertn) ‘Sattabongkot’ and ‘Saddhabutra’

Abstract

Two main problems of cut lotus flower buds are petal blackening and petal discoloration, resulting in short vase life and loss of postharvest quality. In this study, we investigated the effect of magnesium oxide nanoparticles (MgO NP) in terms of maintaining postharvest quality of the lotus cut flower buds (Nelumbo nucifera Gaertn) ‘Sattabongkot’ and ‘Saddhabutra’. Cut flower buds of each cultivar were pulsed with different concentrations of an MgO NP suspension (0, 0.05, 0.1, and 0.3%), for 6 h followed by transfer to distilled water as the vase solution at 27 ± 1°C and 80–85% RH. The longest vase life of 90.0 h was found in ‘Sattabongkot’ when cut flowers were pulsed with 0.1% MgO NP compared with control was 64.8 h. ‘Saddhabutra’ showed the second longest vase life of 87.0 h when pulsed with 0.3% MgO NP and control was 62.2 h. Pulsing with an appropriate concentration of MgO NP (0.1% for ‘Sattabongkot’ and 0.3% for ‘Saddhabutra’) increased water uptake, delayed fresh weight decrease, suppressed ethylene production, and reduced petal blackening in the cut flower buds of both cultivars. Moreover, MgO NP inhibited microbial growth in vase water as indicated by a reduction in microbial population on agar plates as compared with the control. Based on our results, we suggest that 0.1 and 0.3% MgO NP suspensions may be applied as an alternative way to preserve the postharvest quality of cut lotus flower buds.