Effect of Plant Hormones and Preservative Solutions on Post-Harvest Quality and Physiological Senescence Parameters of Cut Leaves of Hosta Tratt. ‘Krossa Regal’ and Polygonatum multiflorum (L.) All. ‘Variegatum’

In recent years, there has been growing interest in the use of native ground-grown perennials in floral compositions as cut greenery. The easily available plant materials that can replace some exotic species include Hosta leaves and the leafy shoots of Polygonatum multiflorum. Their vase life should be at least as long as that of the flowers, with which they are combined. In order to prolong the vase life of cut greenery, the conditioning of cut plant material in solutions of plant hormones (GA3 and BA) and commercial conditioning substances (8HQC and Chrysal Clear 2) is most commonly performed. The aim of this study was to evaluate the effect of different conditioning solutions on vase life and parameters indicating the progression of the senescence of plant materials. Cut Hosta leaves and leafy shoots of Polygonatum multiflorum were conditioned immediately after cutting for 24 h in aqueous solutions of benzyladenine (BA) and gibberellic acid (GA3), 8HQC standard medium with the addition of 2% sucrose and 1% Chrysal Clear 2 solution. The post-harvest storage and physiological senescence parameters of the plant materials were analyzed using the following indicators: the vase life, the relative water content (RWC), electrolyte leakage (EL), and thiobarbituric acid reactive substance (TBARS) and pigment contents (chlorophyll a, chlorophyll b, carotenoids, and anthocyanins). Conditioning Hosta leaves in a BA solution at 100 mg L−1 immediately after cutting more than doubles their post-harvest vase life. The longevity of P. multiflorum shoots can be effectively extended by storage in a BA solution of 400 mg L−1, for 24 h. Both the plant materials responded to the progressive aging process with the disruption of water management, a reduction in cytoplasmic membrane integrity, and a decrease in the plant pigment content. Tissue water retention in the Hosta leaves was most favorably affected by conditioning in the GA3 solution at a concentration of 400 mg L−1. The P. multiflorum shoots responded with tissue water retention to conditioning in 1% Chrysal Clear 2 solution. The conditioning of Hosta leaves in BA solution at 400 mg L−1 stabilized the cytoplasmic membranes and inhibited EL most effectively. In P. multiflorum, the lowest EL level was found as an effect of conditioning the shoots in GA3 solution at 200 mg L−1. The degradation of assimilation pigments was prevented by conditioning the Hosta leaves in GA3 solution at 200 mg L−1 and the P. multiflorum leafy shoots in GA3 solution, regardless of the concentration used. Although the prolongation of the vase life of the cut leaves and the shoots by up to 30 days was achieved, along with an improvement in the appearance of the plant materials, it was not possible to identify a single conditioner that had a positive effect on all the parameters studied.