剑豆光合生理研究

目的]对剑豆光合生理进行初步研究.方法]采用Li-6400光合测定系统,以春季种植的剑豆（Canavalia ensiformis）为研究对象,探讨其光合特性.借助光合助手软件,对剑豆的实测光响应数据进行拟合.结果]剑豆的光补偿点为106.40 μmol/（m2·s）,光饱和点为1 976.80 μmol/（m2·s）.剑豆净光合速率日变化为双峰曲线,第1个峰出现在10：00,为25.48 μmol/（m2·s）,l3：00出现波谷,即“光合午休”现象,14：00出现当日第2个峰值（15.57 μmol/（m2·s））.剑豆净光合速率的大小与气孔导度、胞间CO2浓度、胞外CO2浓度、光合有效辐射、温度、蒸腾速率和空气湿度均存在一定的关系.结论]光合有效辐射对剑豆净光合速率日变的直接效应最大.气孔导度、气温与净光合速率的日变化的直接效应呈负相关.

Study on Photosynthetic Physiology of Canavalia ensiformis

Objective] To study the photosynthetic physiology of Canavalia ensiformis.Method] To determine the photosynthetic characteristics of Canavalia ensiformis,a Li-6400 photosynthetic system analyzer was used in the condition of natural light.Using photosynthesis assistant software,models of light-response curve for Canavalia ensiformis was set up.Result] The results showed that the light compensation point （LCP） of Canavalia ensiformis was 106.40 μmol/（m2 · s）,and the light saturation point （LSP） was 1 976.80 μmol/（m2 · s）,respectively.The diurnal variation of net photosynthesis rate in sunshine day showed as asymmetric double-peak curve.The first peak value appeared at about 10：00 am,it was 25.48 μmoL/（m2 · s）,and then the wave trough turned up at 13：00 showing midday depression.The second peak value appeared at about 14：00 pm,it was 15.57 μmol/（m2 · s）.The net photosynthesis rate of Canavalia ensiformis was related with Cond,Ci,Ca,PAR,Ta,Tr and RH.Conclusion] Hemagogic and correlation analysis indicated that PAR was the most important factor to the daily net photosynthesis rate,and Cond and Ta was negative correlated with net photosynthesis rate.