玉带草光合特性的研究

Study on Photosynthetic Characteristics in Leaf of Phalaris arundinacea var. picta

采用CIRAS-2便携式光合仪对玉带草（Phalaris arundinacea var.picta）叶片细胞间CO2浓度（Ci）、气孔导度（Gs）、净光合速率（Pn）和蒸腾速率（Tr）等有关参数进行测定,并进行光合特性的分析研究。结果表明,玉带草的净光合速率日变化为单峰曲线,在上午10：00达到最大值,此后呈下降趋势;玉带草的净光合速率随着光照度的增大而增大,在光照度1 400μmol/（m^2·s）时达到最大值;当CO2浓度在0～1 000μmol/mol这一范围内时,玉带草净光合速率呈急速上升趋势。可得羧化效率为2.410 9;CO2补偿点为3.08μmol/mol,CO2饱和点为1 000μmol/mol。

By using CIRAS-II portable photosynthesis system,several photosynthesis parameters such as leaf intercellular CO2 concentration（Ci）,stomatal conductance（Gs）,net photosynthetic rate（Pn）,and transpiration rate（Tr） have been determined in the leaf of Phalaris arundinacea var. picta. Photosynthetic characteristics have also been analyzed. The results suggested that diurnal changes of the net photosynthetic rate was one-peak curve in leaves of P. arundinacea var. picta. The peak of net photosynthetic rate appeared at 10：00 am. With the increase of illuminance intensity,the net photosynthetic rate increased and reached the maximum value at 1 400 μmol/（m^2·s）. Net photosynthetic rate increased sharply when the concentration of CO2 was in the 0～1 000 μmol/mol range. The carboxylation efficiency was 2.410 9. The CO2 compensation point was 3.08 μmol/mol,the saturation point of CO2 was 1 000 μmol/mol.