Effects of Exogenous Calcium on Some Postharvest Characteristics of Cut Gladiolus

In order to apply calcium to the vase solutions of cut gladiolus (Gladiolus hybridus), the vase life and some physiological characteristics were studied in this article. A gladiolus cultivar, Mascagni, was chosen for experiments, and its cut flowers were held into solutions, which contained calcium acetate, ethylene glycol bis-amino tetmacetate (EGTA), and water, respectively. The effects of calcium were probed by measuring the ornamental quality of cut gladiolus and the physiological characteristics such as calmodulin (CaM), abscisic acid (ABA), gibberellins (GA), zeatin (ZRs), endogenous calcium, malondialdehyde (MDA), and soluble sugar in florets. In a solution of 2 mmol L−1 calcium acetate, the opening rate of cut gladiolus was higher than that of control, and the vase life and ornamental value of flowers were better than that in control and other treatments of calcium acetate. Thus, the solution of 2 mmol L−1 calcium acetate has the best effect on the fresh keeping of cut gladiolus. In petals and bracts of cut gladiolus, the contents of CaM and GA and the ratios of GA/ABA and ZRs/ABA were higher in treatment of 2 mmol L−1 calcium acetate than that in control, while the contents of ABA and MDA were lower. Compared with the control, the solution of 2 mmol L−1 calcium acetate increased the endogenous calcium contents, and decreased the MDA contents, and alleviated the effects of EGTA on CaM, GA, GA/ABA, and ZRs/ABA. It made the soluble sugar content higher in petals than the control, but lower in bracts. Thus, the solution of 2 mmol L−1 calcium acetate not only stabilizes the membrane structure of cut gladiolus, but also activates CaM. It thereby controls the endogenous hormone levels, and transports soluble sugar into petals, and increases the vase life of the flower.