【摘要】 在自然状态下利用Licor6400便携式光合测定系统测定了两种草坪型高羊茅(凌志和交战Ⅱ)在南京夏季光合生理生态参数的日变化。结果表明,两者在各光合生理生态参数的日变化中存在明显的差异。凌志叶片净光合速率的日变化呈典型的双峰曲线,有明显的光合“午睡”现象。分析表明,这种光合“午睡”属于非气孔限制。与交战Ⅱ相比,凌志在午后表现出较高的净光合速率和水分利用效率以及较低的蒸腾速率,表明凌志比交战Ⅱ高羊茅更能适应炎热夏季。更多还原

【Abstract】 Under natural condition, diurnal changes of photosynthetic physiological parameters in leaves of two tall fescue cultivars (Festuca arundinacea cv. Barlexas and Crossfire Ⅱ) were investigated with Licor-6400 portable photosynthetic system in Nanjing city during summer. The result showed that there were significant differences in diurnal changes of photosynthetic physiological parameters between two tall fescue cultivars. The curve of diurnal variation in net photosynthetic rate (Pn) of Barlexas leaves had two peaks, Barlexas had an obvious midday depression controlled by non-stomatal factor. Compared to Crossfire Ⅱ, Barlexas showed higher Pn, water use efficiency (WUE) and lower transpiration rate (E), which may be important physiological factors of better adaptation to hot summer.更多还原