Study on The Effect of Plant Growth Regulators Gibberellic Acid and Thidiazuron on Vase Life and Qualitative Traits of Two Cultivars of Alstroemeria: ‘Odessa’ and ‘Sacramento’

The effect of plant growth regulator short time treatments ( GA3 and TDZ) on the increase of vase life and qualitative traits of Alstroemeria cultivars ‘Odessa’ and ‘Sacramento’ were investigated. Cut flowers were treated with 24h pulse treatments which included different concentrations of GA3 and TDZ. Cut flowers were later held in preservative solution (Sucrose 2% +Nanosid 2ppm) and then their vase life and qualitative traits evaluated on different days. The results indicated that GA3 300 µM treatment in ‘Odessa’ increased flower longevity while GA3 150 and 300 µM treatments increased leaf longevity. Moreover, GA3 300 µM treatment in ‘Sacramento’ deeply prevent affected the prevention of leaf senescence whereas the preservative solution more conspicuously affected the increase of flower longevity. In addition, 2ppm antibacterial Nanosid diminished the growth of microorganisms in preservative solution, in comparison with control (distilled water) and 2% Sucrose overcome the lack of carbohydrates in respiration process in cut flowers. Relative fresh weight and total soluble solids in stem increased in all treatments except in control. Also, GA3 (50, 150 µM) in ‘Odessa’ and GA3 300 µM in ‘Sacramento’ exhibited the maximum rate of total chlorophyll on the 12th day. Consequently, short duration treatment with 300 µM of GA3 is recommended in increasing the vase life and quality of cut flowers in ‘Odessa’ and ‘Sacramento’. Odessa’ is considered as a superior cultivar over ‘Sacramento’ and Nanosid in preservative solution being acknowledged as an appropriate antibacterial agent.