Photosynthetic characteristics of Camellia gauchowensis

The purpose of this study was to explain photosynthetic characteristics of the leaves of Camellia gauchowensis, providing a theoretical basis and technical guidance for the selection of fine resources, as well as effective management and cultivation of C.gauchowensis.

Photosynthetic characteristics of the leaves of C.gauchowensis were determined by a LI-6400 portable photosynthesis analysis system.

Diurnal variations in net photosynthetic rate (Pn) of the mature trees of C.gauchowensis presented a double-peak curve.The light saturation point was 1 417 μmol·m^-2·s^-1, with the light compensation point being 18.92 μmol·m^-2·s^-1, Pn_max being 12.58 μmol·m^-2·s^-1.The diurnal variation in transpiration rate (Tr) of the mature trees of C.gauchowensis was characterized by a single-peak curve.The maximum of Tr of the mature trees was 3.65 mmol·m^-2·s^-1. The diurnal variations in intercellular CO₂ concentration (C_i) of C.gauchowensis presented a "U" curve in each month.The diurnal variations in water use efficiency (WUE) of mature trees presented a "down-up-down" curve all the year round.The diurnal variations in stomatal conductance (G_s) of mature trees presented a double-peak curve or a single-peak curve.In July, September, November and January, the diurnal variations in G_s of mature trees were both double-peak curves, and in March it was single-peak curves.Photosynthetically-active radiation, air temperature, atmospheric CO₂ concentration, Tr and G_s were the main factors which influence the Pn of C.gauchowensis.