Postharvest Treatments Improve Quality of Cut Peony Flowers

Abstract

Peony is one of the most important ornamental plants in the international flower market, but has a relatively short vase life in water. This study tested the effects of 8-hydroxyquinoline citrate (8-HQC) and nanosilver (NS) in combination with sucrose, as well as two commercial preservatives, on the longevity and some physiological and biochemical aspects of senescence of cut flowers of 14 cultivars. Responses varied both by cultivar and treatment. The preservatives extended the vase life in only five cultivars; however, in nine cultivars, preservatives increased the flower diameter and improved the general flower appearance. Blockages in xylem vessels started to appear soon after harvest. Both NS and 8-HQC with sucrose prevented tylose formation, while bacterial blockages were reduced only by the NS solution. Reduction in stem blockages did not translate into better water balance or flower longevity. The highest carbohydrate accumulation in petals was observed in the NS solution. Preservatives mitigated the rise in free amino acids, including free proline. They did not prevent an increase in H2O2 content but flowers in preservatives generally had higher catalase activity than in the control. As solutions with NS produced comparable or even better results than 8-HQC, we recommend the latter as a component of a preservative for cut peony flowers. However, cultivar-specific responses indicate that postharvest treatments must be individually tailored to each cultivar.

Effects of Postharvest Treatments with Nanosilver on Senescence of Cut Lisianthus (Eustoma grandiflorum (Raf.) Shinn.) Flowers

“…A delay in senescence in lisianthus by endogenous hydrogen was also associated with increased activity of CAT [39]. In cut peonies, the CAT activity increased during the vase life and was higher in flowers held in preservatives, especially in NS + S [40].…”

Pre- and/or Postharvest Silicon Application Prolongs the Vase Life and Enhances the Quality of Cut Peony (Paeonia lactiflora Pall.) Flowers

“…The postharvest flower opening stage was evaluated as soon as the cut flowers were placed in the holding solutions. The vase life of the postharvest cut peony flowers could be defined by summing the number of days from harvest to the initial wilting and/or petals falling [ 22 ]. The flower opening stages after harvest were markedly classified into six phases based on their changes in appearance ( Figure 1 ).…”

Do Eco-Friendly Floral Preservative Solutions Prolong Vase Life Better than Chemical Solutions?

“…The hydraulic conductivity of flower stems decreases with the number of bacteria per cut flower stem fresh weight [100][101][102]. A number of germicide solutions have been used to extend the vase life of cut flowers, including the silver compounds: STS [12,103] and AgNO 3 [103]); chlorine compounds (sodium hypochlorite, sodium dichloroisocyanurate, and ClO 2 [5]), and certain other compounds, such as 8-HQS [12], 8-Hydroxyquinoline citrate (8-HQC) [104], salicylic acid (SA) [105], calcium [106], calcium nitrate [107], aluminum sulfate [108,109], isothiazolinone [49], and quaternary ammonium chloride [110]). To prevent microbial growth, a sugar solution is always added to a biocide solution [78].…”