Abstract: This research aimed to explore in detail the effects of three light regimes [white light (WL), red light (RL), and blue light (BL)] on growth status and physiological and biochemical traits of Sarcandra glaba seedlings. Measures of plant growth status conducted were: plant height, stem diameter, total fresh weight (roots and shoots), total dry weight (roots and shoots), root morphology indexes, and root∶shoot ratio. Physiological and biochemical traits measured included chlorophyll, solution protein, solution sugar, reducing sugar, and malondialdehyde (MDA) concentrations of leaf tissues; peroxidase (POD) and superoxide dismutase (SOD) activities, net photosynthetic rate (P_n), maximum light use efficiency (LUE_max), maximum water use efficiency (WUE_max) and maximum photosynthetic efficiency (F_v/F_m). Most of the measured traits showed differences between light regimes. Compared with WL and BL groups, the RL treatment resulted in a significant reduction in a majority of the measured traits. Exceptions were plant height and WUE_max which were increased in RL. Compared with the WL treatment, in the BL light regime, root morphology indexes, root∶shoot ratio, protein and MDA concentrations, POD and SOD activities and WUE_max were considerably increased, while other indexes were decreased. In this experiment, the RL treatment resulted in a significant decrease in many traits. Meanwhile, the BL regime not only stimulated root morphology indexes, but also improved WUE_max. This research lays a theoretical foundation for developing light quality guidelines for the cultivation of S. glaba seedlings.

Key words: Sarcandra glaba, light qualities, physiological and biochemical indexes, maximum water use efficiency, maximum light use efficiency, maximum photosynthetic efficiency