Effects of elevated CO2 on vase quality, physiological and structural characteristics of cut chrysanthemum.

【Objective】 The effects of elevated CO2 on vase quality, physiological and structural characteristics of cut chrysanthemum were investigated for the purpose of applying elevated CO2 to the fresh-keeping cut chrysanthemum and even other cut flowers. 【Method】 Cut flowers of Chrysanthemum morifolium ‘Sijihuang’ were firstly held into deionized water, and then subjected to 380 (the control) and 760 (elevated CO2) μmol·mol-1 CO2 , respectively. The changes in morphology, physiology and structure were examined using portable photosynthesis system, the technique of paraffin section, transmission electron microscopy, and some other physiological methods. 【Result】 Compared with the control, elevated CO2 increased fresh weight and flower diameter of cut chrysanthemum, retarded its senescence, and extended its vase life. In addition, compared with the control, elevated CO2 enhanced photosynthetic rate, contents of chlorophyll and soluble sugar, and activities of superoxide dismutase (SOD) and peroxidase (POD), but reduced malondialdehyde (MDA) content. Furthermore, elevated CO2 retarded cell degeneration in leaves and petals in comparison to the control. 【Conclusion】 It is possible that elevated CO2 may provide more carbohydrates for normal cell metabolism of cut flowers through directly increasing photosynthetic rate, and indirectly retarded cell degeneration by enhancing the activities of SOD and POD. As a consequence, elevated CO2 extended the life of cut flowers.