The Photosynthetic Characteristics in Leaves of Malana oleifera Seedlings

With LiCor-6400 Portable Photosynthesis Analysis System,light compensation point and saturation light intensity for the Malana oleifera seedlings grown in greenhouse were studied.By controlling light intensity,CO2 concentration,temperature and humidity in the leaf chamber,carboxylation efficiency and CO2 compensation point were analyzed and laboratory studies were conducted to investigate the relations between photosynthetic rate and light intensity,temperature and humidity.Compensation irradiance was 8.1 μmol·m-2·s-1.Saturation light intensity was about 750 μmol·m-2·s-1.Carbozylation efficiency of leaves was about 0.022 67 and CO2 compensation point was 53.2 μmol·mol-1.The net photosynthetic rate reaches the maxium 25 ℃,the optimal temperature was from 18 to 31℃.When humidity went up from 20% to 80%,the rate of net photosynthesis increased.The optimal humidity was above 50%.