二回原始观音座莲蕨光合作用的生理生态学研究

Studies on the physiological ecology of photo- synthesis of Archangiopteris bipinnata

利用 CO2 光合测定仪分析了引种栽培的二回原始观音座莲叶片的光合补偿点和光合饱和点及其日变化 ,通过控制叶室的光合有效辐射、CO2 浓度、温度和相对湿度 ,分析了叶片的羧化效率和 CO2 补偿点 ,并进行光合有效辐射 ,温度或相对湿度对光合速率的单因子影响研究。二回原始观音座莲的二回羽状复叶上午、中午和下午的光合补偿点分别为 6 .1、6 .4和 3.1μmol/m2 s,光合饱和点分别为 2 50、50 0和 2 50 μm ol/m2 s。最适光合有效辐射为 10 0～ 50 0μmol/m2 s。叶片的羧化效率为 0 .0 191,CO2 补偿点为 59.1μmol/m ol。光合速率在叶温 2 2～ 2 8°C范围内 ,随温度升高上升 ;2 8～ 33°C随温度升高下降 ,最适温度为 2 4～ 30°C。相对湿度 30 %～85%的试验范围内 ,叶片光合速率随湿度增加而增大 ,最适相对湿度条件在 75%以上。

With LI-6400 Portable Photosythesis Analysis System,light compensation point,light saturation point and their diurnal variation for a pteridophyte Archangiopteris bipinnata planted in greenhouse were studied. By controlling light,CO 2 concentration,temperature and humidity in the leaf chamber,carbozylation efficiency and CO 2 compensation point were analyzed and laboratory studies were conducted to investigate relations between photosynthetic rate and light,temperature or humidity. Compensation irradiance has diurnal variation,6.1 μmol/m2s in the morning,6.4 μmol/m2s at noon and 3.1 μmol/m2s in the afternoon. Saturation irradiance in the morning and afternoon was 250 μmol/m2s,500 μmol/m2s at noon. The optimal photosynthetic active radiation was from 100 to 500 μmol/m2s.Carbozylation efficiency of leaves was about 0.019 1 and CO 2 compensation point was 59.1 μmol/mol. The rate of net photosynthesis increased when leaf temperature increased from 22 to 28 °C,but decreased above 28 °C. The optimal temperature was from 24 to 30 °C. When humidity provided in the leaf chamber went up from 30% to 85%,the rate of net photosynthesis increased. The optimal humidity was above 75%.