不同生长速度杨树品种的光合生理特性研究

Physiological Characteristics of Hotosynthesis in Different Poplar Varieties

对4个杨树品种小青杨(Populus pseudo-simonii)、107(Populus×euramericana`Neva')、108(Populus×euramericana`Guarien-to')和W13的光合生理特性进行对比研究,结果表明:速生杨树品种的叶面积、比叶面积均高于小青杨,4个杨树品种的光-光合作用响应拟合曲线均为直角双曲线,方程为Pn=α×PFD×Pmax/(α×PFD+Pmax)-Rd;各品种的光合作用基本特征参数为:W13的光能利用率最高,其次是107,108,小青杨最低,仅为W13的39%;最大光合速率由高到低依次为107,108,W13,小青杨,呼吸速率的绝对值由大到小依次为107,W13,108,小青杨,表观量子需要量由高到低依次为小青杨,107,108,W13,4个品种中只有W13的表观量子需要量低于20;随着光合有效辐射强度的增强,各品种均表现为Ls值增大、Ci值下降的趋势。通过综合比较分析可知,小青杨本身光合生产力低是造成低产林的内因之一。

The physiological characteristics of three fast-growing poplar varieties were compared to those of an indigenous poplar species, Popuhts pseudo-simonii. The results showed that the leaf area and the specific leaf area of the fast-growing varieties was larger than that of P. pseudo-simonii. The light-photosynthetic curves of the varieties were all approximate to a rectangular hyperbola under suitable conditions, namely Pn=α×PFD×Pmax/（α×PFD＋Pmax）-Rd .Based on the equation, the photosynthetic parameters of different poplar varieties were as follows. The solar energy utilization efficiency of W13 was the highest, followed by 107 and 108, Populus pseudo-simonii was the lowest, 39% of W13. The maximum photosynthetic rate of the varieties was 107〉108〉W13 Populus pseudo-simonii. The respiration rate was 107〉W13〉108〉Populus pseudo-simonii. The apparent quantum requirement was Populus pseudo-simonii〉107〉108〉W13. With increase of PFD, Ls of the four varieties increased and Ci decreased.