Effect of inhibitors of lignin biosynthesis on vase life of gerbera cut flowers

A major problem associated with cut Gerbera flowers is short postharvest life that resulted in rapid stem bending. The main objective of the present study was to investigate the effect of lignin biosynthesis inhibitors as vase solutions on the vase life of Gerbera (Gerbera jamesonii cv. Danish). Gerbera cut flowers were treated with chemical inhibitors include EDTA (5, 10 and 15mM), NaF (0.06, 0.08 and 0.1mM) and NaN3 (0.05, 0.1 and 0.2mM). Cut stems were placed in these solutions for 20 h at 20°C (Pulse treatment). Results showed that sodium fluoride at 0.06 mM and sodium azide at 0.2mM were more effective in increasing vase life of cut flowers (14 days) than other treatments. Tip burning in ray florets was found at the highest concentration tested of sodium fluoride (0.1mM). Also, sodium azide at 0.2mM showed significant (P<0.01) positive effects on maintenance of fresh weight (51.8%), water uptake (49.81%), flower diameter (44.94%) and anthocyanin content (61.8%) compared to control. In contrast, longevity of cut gerbera was not increased with EDTA treatment. The data showed that EDTA caused high toxicity and hastened the time to bending of stem. Therefore, lignin biosynthesis inhibitors such as sodium azide and sodium fluoride probably extended vase life by controlling wound healing and delaying occlusions at the cut stem ends. Thereby, they facilitate the absorption of solution and reduce the rate of decline in relative fresh weight in the Gerbera cut flowers.