Study on Davidia involucrata leaf photosynthesis diurnal variation characteristics

In order to understand the photosynthetic physiological characteristics of Davidia involucrata, using portable LI-6400 photosynthesis Davidia involucrata measured net photosynthetic rate ( Pn), stomatal conductance (Gs), CO2 concentration between cells (Ci) and transpiration rate (Tr). Results: Davidia involucrata leaf net photosynthetic rate (Pn) and diurnal variation of transpiration rate (Tr) diurnal variation showed a bimodal curve, " midday depression" phenomenon obviously; CO2 concentration in stomatal conductance (Gs) diurnal and cell (Ci) diurnal variation of the overall trend is decrease, and both were significantly negatively correlated with net photosynthetic rate, but the intercellular CO2 concentration (Ci) at 16:00 reached its lowest point and then showed a rising trend began.