滇重楼光合作用与环境因子的关系

 利用LI-6400光合测定仪和人工气候箱研究了滇重楼叶片的光合补偿点、光合饱和点、羧化效率和CO₂补偿点,并进行温度、相对湿度对光合速率的单因子影响研究.滇重楼叶片的光合补偿点为5.7μmol/(m²·s),光合有效辐射增至2000μmol/(m·s)²仍未测到光合饱和点,最适光合有效辐射为750～2000μmol/(m·s)².叶片的羧化效率为0.0295,CO₂补偿点为65μmol/mol,光合速率随CO₂浓度升高而明显增加,高于大气正常值的CO₂浓度对增加滇重楼光合作用的光能利用率是有利的.光合速率在温度11～20℃范围内,随温度升高上升;20～35℃随温度升高下降,最适温度为16～28℃.相对湿度20%～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.

Relationl between the photosynthesis of Paris polyphylla var. yunnanensis and the environmental factors

Light compensation point,saturation light intensity,CO₂ compensation point carbozylation efficiency and the effect of temperature and humidity on the photosynthetic rate of Paris polyphyllavar.yunnanensiswere studied with the photosynthesis analysis system and in the phytotron.It shown light compensation point,CO₂ compensation point and carbozylation efficiency was 5.7μmol/(m²·s),65μmol/mol and 0.0295 respectively,but the saturation light intensity was not monitored even if the photosynthetic active radiation increased from 0 to 2000μmol/(m²·s) and the optimal radiation was from 750 to 2000μmol/(m²·s).The net photosynthetic rate increased with CO₂ concentration increasing,the CO₂ concentration over normality would enhance utilization efficiency of light energy in photosynthesis.When the leaf temperature increased from 11℃ to 20℃ the net photosynthetic rate increased,but it increased from 20℃to 35℃,the rate decreased.The optimal temperature was from 16℃ to 28℃.When relative humidity went up from 20% to 85%,the net photosynthetic rate increased.The optimal humidity was above 75%.