Application of melatonin and sucrose in prolonging the vase life of amaryllis cut flowers (Hippeastrum Hybridum Herb)

Abstract The effects of melatonin application by itself and mixed with sucrose solution on vase life and physicochemical changes in amaryllis cut flowers were investigated. Amaryllis stems with flower buds at harvest points were placed into vases containing different maintenance solutions: Melatonin (Mt; 0.01 mM), Sucrose (Suc; 4%), Melatonin + Sucrose (Mt + Suc; 0.01 mM + 4%) and distilled water (Control). Each treatment consisted of five repetitions, with one inflorescence stem per vase. The vases remained at 22 ± 3 °C and constant lighting of 13 µmol m-2 s-1 for 14 days. Immersion of stems in Suc or Mt + Suc delayed the initial senescence processes of the amaryllis cut flower. Vase life was prolonged for additional 2 days compared to stems immersed in water (control), increasing from 10 to 12 days of conservation. Floral stem mass was kept more stable; the degradation of anthocyanin and flavonoid pigments was delayed; and the stability of phenolic compounds and total carbohydrates was maintained for 14 days. These findings confirm the role of melatonin as a preservative in cut flowers. However, its preservative effect was potentialized by the addition of sucrose to the water of the amaryllis cut flowers. More work needs to be carried out to investigate the physiological mechanisms promoted by the interaction of melatonin and sucrose in the regulation of senescence in amaryllis cut flowers, including the analysis of gene expression and activity of the antioxidant system. Resumo O presente trabalho investigou os efeitos da aplicação de melatonina individualmente e misturada com solução de sacarose na vida de vaso e nas alterações físico-químicas de flores de corte de amarílis. Hastes de amarilis com botões florais em pontos de colheita foram colocadas em vasos contendo diferentes soluções de manutenção: Melatonina (Mt; 0,01 mM), Sacarose (Suc; 4%), Melatonina + Sacarose (Mt + Suc; 0,01 mM + 4%) e Água destilada (Controle). Cada tratamento constou de 5 repetições, sendo uma haste de inflorescência por vaso. Os vasos permaneceram a 22 ± 3° C e iluminação constante de 13 µmol m-2.s-1 durante 14 dias. A imersão das hastes em Suc ou Mt + Suc retardou os processos iniciais de senescência de flor de corte de amarílis, prolongando por mais 2 dias sua vida de vaso, em relação às hastes sem uso desses conservantes (controle). Aumentando de 10 para 12 dias de conservação. Pois mantiveram mais estáveis a massa fresca, retardaram a degradação de pigmentos antocianinas