关键词: 显脉金花茶, 净光合速率, 光饱合点, 光补偿点

Abstract: The photosynthetic characteristics of leaves in Camellia euphlebia were studied with LI-6400 (Li-Cor Inc., USA) portable photosynthesis system. The results showed that the diurnal changes of photosynthetic rate (P_n) in C. euphlebia exhibited a mono-peak style, and the maximum value of P_n appeared at 11:00 am in summer. The maximum photosynthetic rate（P_max）, light saturation point（LSP）, light compensation point（LCP）for the leaves of C. euphlebia were 3.81 μmol·m^-2·s^-1, 459.9 μmol·m^-2·s^-1 and 6.9 μmol·m^-2·s^-1, respectively. The light saturation and compensation point were very low, which indicated that C. euphlebia was a shade plant. Under the condition of optimum light intensity and temperature, the net photosynthetic rate of C. euphlebia increased linearly when the concentration of CO₂ enhanced from 50 μmol·mol^-1 to 800 μmol·mol^-1. Elevation of CO₂ concentration increased the P_n and the efficiency of ligh utilizing in C. euphlebia. The CO₂ saturation (CSP), compensation point（Г^*）, the maximum carboxylation rate （V_cmax）and maximum rate of electron transport（J_max） were about 1 200 μmol•mol^-1, 70.1 μmol·mol^-1, 17.5 μmol·m^-2·s^-1, respectively.

Key words: Camellia euphlebia, net photosynthetic rate, light saturation point, light compensation point