Photosynthetic characteristics of Camellia gauchowensis

Objective 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.

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

Result and conclusion 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.