Effects of Pulse Treatments with Sucrose, Silver Thiosulfate Complex (STS) and Calcium Chloride on the Vase Life and Soluble Carbohydrate and Aurone Levels in Cut Snapdragon Flowers

Abstract

The effects of pulse treatments with 0.2 mM silver thiosulfate complex (STS), 5 and 10% sucrose, and 0.2% calcium chloride (CaCl₂) and their combinations on the vase life and soluble carbohydrate and aurone levels in cut snapdragon (Antirrhinum majus) flowers were investigated. In the pulse treatment, the cut flowers were treated with these chemical solutions for 24 h before being transferred to distilled water. The uptake of solution for pulse treatments was decreased in the treatments with STS, sucrose, and CaCl₂ and the combined STS and sucrose treatment further suppressed uptake. The sucrose treatment significantly increased the number of open flowers and extended the vase life, with no marked differences in these effects between the 5% and 10% sucrose solutions. The STS treatment slightly promoted flower opening but did not significantly extend vase life. The CaCl₂ treatment did not affect flower opening or vase life. The relative fresh weight (RFW) and water uptake of cut flowers were increased in the sucrose treatments and were only slightly affected by the STS and CaCl₂ treatments. The petal aurone levels were significantly higher in the sucrose treatments, particularly at 10% sucrose. The glucose, fructose, and sucrose petal contents were generally higher in the sucrose treatments than in the treatments that did not include sucrose. The ethylene production of flowers was relatively low at harvest and somewhat increased during senescence. Therefore, the infectiveness of STS on vase life may be due to low ethylene production. We conclude that pulse treatments with solutions containing sucrose increase the sugar contents and aurone levels in petals, as well as improve the vase life of cut snapdragons.