Comparison study on photosynthetic response to short-term elevated CO_2 in leaves of three developing stages of Ginkgo biloba L.

LI-6400 photosynthesis measure system was used to measure the responses of Pn to short-term elevated CO2 in expanding leaves,young fully expanded leaves and mature leaves of Ginkgo biloba L.CCP、CE、Vcmax and Jmax were calculated by photosynthesis assistant software according to Pn-CO2 curve.Results were summarized as follows:The responsive curves of Pn in leaves of three development stages of Ginkgo biloba L.to elevated CO2 concentration could be described with quadratic equations.On the same condition,the Pn of mature leaves was the highest and that of expanding leaves was the lowest.The CCP of mature leaves was the lowest and the CE,Jmax and Amax were the highest.Photosynthetic characteristics of young fully expanded leaves were more similar to expanding leaves.