Effects of per-harvest applications of different source of calcium on the quality of ‎gerbera (Gerbera jamesonii L.) flower in two cultivars of intense and rosaline‎

Gerbera flower belongs to the Composite family and is one of the five top cut flowers in the world in terms of production and consumption, which has a great economic value in the international flowering industry. This study was designed to evaluate whether calcium pre-harvest foliar application in hydroponic culture, provided through 0, 0.5, 1 and 1.5% of CaCl2 and CaNO3, could extend quality of gerbera cut flower. The layout was factorial experiment in completely randomized design (CRD) with four replication.  Afterwards, for evaluation of associated traits with vase life, the produced flowers were kept in a vase solution containing 200 mg/L hydroxyquinoline sulfate with temperature conditions of 20 °C. The results showed that vase life of flowers extended 6.1 and 5 days by application 1% CaCl2 for Intens and Rosalin respectively. All treatments were effective in the increasing relative fresh weight of flower due to increase water uptake. The results also revealed that the calcium pretreatment delayed flowers senescence and maintained leaf protein and petal anthocyanin content. Application of calcium resulted in a decrease in electrolyte leakage and malondialdehyde content in the cut flowers of both cultivars, providing evidence for delay of senescence in calcium-treated cut flowers. Also, results showed that calcium application significantly increased Peroxidase (POD) and phenylalanine ammonia-lyase (PAL) of both cultivars.  The maximum and the minimum PAL and POD activities were observed in resistant and sensitive cultivars, respectively. Taken together, pre-harvest application of calcium (especially 1% CaCl2) might be promising approaches to improve postharvest performance of gerbera cut flowers.