纳罗克非洲狗尾草光合生理日变化研究

在昆明市利用Ci-310便携式光合测定仪测定了纳罗克非洲狗尾草（Setaria sphacelata stapf cv.Narok）种子田夏季光合生理参数的日变化.对大气温度、CO2浓度、相对湿度、植物气孔导度、胞间CO2浓度、蒸腾速率、瞬时水分利用率、光合有效辐射、净光合速率等参数进行分析,结果表明：纳罗克非洲狗尾草光合生理特性受环境影响呈规律性变化,光合速率、光合有效辐射、气孔导度和蒸腾速率的日变化呈双峰曲线,存在“午睡”现象.非气孔限制为引起光合“午睡”的主要原因,其中净光合速率降低为叶肉光合活性下降所致.

Analysis of the Diurnal Variation of Physiological Parameters of Setaria sphacelata Stapf cv.Narok

The diurnal variation of physiological parameters of Narok Setaria seeds （Setaria sphacelata stapf cv.Narok） were measured by using the Ci-310 portable photosynthesis. The variables, e.g. the atmospheric temperature, CO2 concentration, relative humidity, stomata conductance, CO2 concentration between cells, transpiration rate, efficiency of water application, photosynthetic active radiation, net photosynthetic rate, were recorded. The results showed that Narok Setaria photosynthetic characteristics appeared regular variation with the change of the environment. A bimodal curve was found for photosynthetic rate, photosynthetic active radiation, stomata conductance and transpiration rate, and a ＂ siesta＂ phenomenon was also observed. The main reason caused ＂ siesta＂ phenomenon was non-stomata limitation which reduced net photosynthetic rate decrease in leaf photosynthetic activity.