紫叶稠李的光合特性初探

Preliminary Study on Photosynthetic Characteristics of Padus virginiana ‘Schubert’

本文研究了紫叶稠李光合特性的日变化。结果表明,紫叶稠李叶片净光合速率日变化呈双峰曲线,存在明显的“午休”现象。在10∶00时达到第一个最高峰值,在整个日变化中表现最大,于12∶00时下降至谷值,在14∶00时达到第二个次高峰值,之后逐渐下降。蒸腾速率日变化曲线为单峰型,于12时达到峰值。水分利用效率日变化呈双峰曲线,在10∶00时和16∶00时其水分利用效率较大,12∶00时其水分利用效率较小。

This paper studied the diurnal photosynthetic characteristics variation of p Padus virginiana‘Schubert’.The results showed that the diurnal variation of net photosynthetic rate showed a bimodal curve,and there was an obvious“noon break”phenomenon.It reaches the first peak at 10∶00,drops to the valley at 12∶00,reaches the second peak at 14∶00,and then decreases gradually.The daily variation curve of transpiration rate was unimodal and reached its peak at 12∶00.The diurnal variation of water use efficiency(WUE)showed a bimodal curve.WUE was the higher at about 10 am and 4 pm,the lower at 12∶00 am.