不同地理种源翅荚木苗期光合特征的日变异规律

Daily Variation Regulation of the Photosynthetic Characteristics of Zenia insignis Seedlings from Different Geographic Provenances

为研究不同地理种源翅荚木苗期光合特征的日变异规律,利用LI-6400光合测定仪于夏季末期对翅荚木苗期的光合特征进行了测定与分析.研究结果表明:(1)翅荚木各种源苗期上部叶片净光合速率日变化为"双峰"型;气孔导度除通道种源为"双峰"型外,其它种源为"单峰"型;蒸腾速率是桂林、江华、通道种源为"双峰"型,忻城、靖西、平果、融水、英德、韶关、兴义种源为"单峰"型.(2)翅荚木各种源下部叶片净光合速率的日变异规律除平果种源为"单峰"型外,其它种源为"双峰"型;气孔导度是忻城、靖西、桂林、平果、兴义种源为"单峰"型,融水、英德、韶关、江华、通道种源为"双峰"型;蒸腾速率是靖西、桂林、兴义种源为"单峰"型,忻城、平果、融水、英德、韶关、江华、通道种源为"双峰"型.(3)所有种源上部叶片和下部叶片胞间CO2浓度的日变异规律为"V"字型.(4)所有种源的上部、下部叶片以傍晚的净光合速率为全天最低,气孔导度值在全天中以傍晚时最低,胞间CO2浓度以清早为最高、下午14:00最低,蒸腾速率在全天中以傍晚时最低.(5)各种源上部叶片的净光合速率、气孔导度、蒸腾速率明显大于下部叶片的值.

For a general study of Zenia insignis seedlings from different geographic provenances and the daily variation regulation of their photosynthetic characteristics, their photosynthetic characteristics were measured and analyzed in late summer by employing an LI-6400 portable photosynthetic determiner. The results show that the daily variation regulation of their net photosynthetic rate in position of upper-layer crown takes on a doublepeak curve but that of their stomatal conductance in the same position takes on only a single-peak curve except for the seedling from Tongdaot that the regulation of the transpiration rate in position of upper-layer crown of Zenia insignis seedlings from Guilin, Jianghua and Tongdao also has a double-peak curve but that of the others a single-peak curvet that the regulation of their net photosynthetic rate in position of lower-layer crown still enjoys a double-peak curve except for the seedling from Pingguo; that the regulation of the stomatal conductance of the seedlings from Yicheng, Jingxi, Guilin, Pingguo and Xingyi enjoys a single-peak curve but that of the others a double-peak curvet that the regulation of the transpiration rate of the seedlings from Jingxi, Guilin and Xingyi does a single-peak curve while that of the others a double-peak curvet that the regulation of the CO2 concentration between the cells in position of upper-and lower-layer crown of Zenia insignis seedlings from all provenances takes on a V curve ; that the minimum values of the net photosynthetic rate, the transpiration rate and the stomatal conductance of the seedlings from all provenances appear at evening while their CO2 concentration between the cells has a maximum value at early morning and a minimum value at 4：00 pm; and that the upper-layer crown values of the net photosynthetic rate, the stomatal conductance and the transpiration rate of the seedlings from all provenances are all bigger than their corresponding lower-layer crown ones.