Abstract: This study explored the effects of different light qualities (red, blue, and white) on chlorophyll fluorescence parameters and antioxidant enzyme activities in leaves of Schima superba andCunninghamia lanceolata seedlings. The results showed that original fluorescence (F_o), maximal fluorescence (F_m), variable fluorescence (F_v) and steady state fluorescence (F_t) ofS. superba seedling leaves were the highest under the white light. The photochemical efficiency (F_v/F_m), potential activity (F_v/F_o) and antenna transfer efficiency (F_v′/F_m′) of PSII reaction center under different treatments followed trend: white light > blue light > red light. Compared to the white light, the blue light significantly increased the activity of superoxide dismutase (SOD). The red and blue light decreased the activity of catalase (CAT) but increased the activities of peroxidase (POD) and the content of malonaldehyde (MDA).F_oand F_t ofC. lanceolata seedlings were the highest under the red light.F_m andF_v were the highest under the white light.F_v/F_m,F_v/F_o andF_v′/F_m′ratios were the highest under the white light, followed by the blue and red light treatments. Light quality had no significant effect on SOD activity, CAT activity and MDA content ofC. lanceolata seedling leaves, while it had significant effects on POD activity, with a highest value under the white light. In short, light quality would regulate the seedling growth of both tree species examined here. The potential vitality of S. superba andC. lanceolata seedlings decreased under red and blue light treatments due to light stress and unbalanced antioxidant enzyme system. Consequently, red and blue light would be unfavorable for seedling growth.

Key words: water use, water-fertilizer integration, photosynthetic characteristics, grain yield, wheat