Abstract:

This study explored the effect of preservation solutions containing different types of aluminum salts on adjusting red (pink or reddish-pink) cut flowers of hydrangea to blue, with the aim of identifying suitable aluminum salts and their optimal concentrations to achieve both color transition and acceptable vase life. Using Kelixian professional 2 preservative as a control, the vase life and blueing time of red (pink or reddish-pink) cut flowers of hydrangea were observed under treatment with Kelixian professional 2 preservative containing different types of aluminum salts and concentrations of aluminum citrate. The aluminum ion content in flower branches and sepals of cut flowers of hydrangea under different aluminum citrate treatments was also measured. Additionally, the effects of different branch lengths and leaf numbers on the vase life and blueing time of cut flowers of hydrangea were studied. The results showed that preservation solutions containing aluminum citrate made red (pink or reddish-pink) cut flowers of hydrangea turn blue during the vase period. The longer the flower branches and the more leaves there were, the longer the time for the sepals to turn blue, while the vase life of cut flowers of hydrangea was significantly shortened. Higher concentrations of aluminum citrate (0.010 0 mol·L^-1) can significantly shorten the blueing time for cut flowers of hydrangea and also significantly shorten the vase life; The preservation solutions containing lower concentrations of aluminum citrate (0.002 5 and 0.005 0 mol·L^-1) relatively prolonged the blueing time and vase life of cut flowers of hydrangea, and can be used as a working concentration for making red (pink or reddish-pink) cut flowers of hydrangea turn blue. The higher the concentration of aluminum citrate in the preservation solutions was, the faster the cut flowers absorbed aluminum ions, and the more aluminum ions were transported and stored in the sepals.

Key words: hydrangea, cut flowers, aluminum citrate, vase life, adjusting flower color to blue