The Photosynthetic Characteristics In Leaves Of Davidia Involucrate Seedlings

1-year of Davidia involucrate seedlings was used in the experiment.Photosynthetic characteristics of1-year Davidia involucrate seedlings were measured with the Licor-6400portable photosynthetic system. Therefore,photosynthetic ability was improved and accumulation of photosynthetic products was increased. We expected to provide theoretical foundation and actual meanings at the same time for cultivating the Davidia involucrate was scientifically. The main results were as follows:1、The photosynthetic characteristics of Davidia involucrate was demonstrated seasonal variation obviously.The photosynthetic rate has a characteristic "type" changes, from April to start to rise. in July, and then as you reach the highest temperature drop, The photosynthetic rate falling rapidly, in September to lowest. In July, the ability to maintain photosynthesis at a high level, is a important photosynthesis product of the accumulation of period.2、For1-year Davidia involucrate seedlings, the variation of diurnal net photosynthetic rate(Pn) was double-peak curve at sunny days in summer, which means there was a significant "noon break" phenomenon caused by stomas.3、The light compensation points topped57.27μmol·m-2s-1and the light saturation point was625.07μmol·m-2s-1. which indicated that Davidia involucrate was a sun-favor plant, but its range of light adaption was narrow.3、The solar energy utilization efficiency of the seedlings was low, about0.0705mmol CO2/mol photons. Using the stepwise multiple regression we found that PAR, Tr, Gs and Ci were the most dominant factors affecting the photosynthetic rate of1-year Davidia involucrate seedlings.