两种光照下低海拔引种云锦杜鹃的光合作用日变化

以移栽的野生云锦杜鹃Rhododendron fortunei为材料,使用LI-6400便携式光合作用仪,分析10%光照和全光照下低海拔区域引种云锦杜鹃的光合日变化,结果显示10%光照下生长的云锦杜鹃蒸腾速率低于全光照下生长的云锦杜鹃,而水分利用效率高于全光照下云锦杜鹃的60.17%。两种光照下的云锦杜鹃净光合速率和蒸腾速率日变化呈现"单峰"型。全光照下净光合速率下降是非气孔限制引起的,而10%光照下则为气孔限制引起。研究说明种植在低海拔环境的云锦杜鹃喜光的特性并不因为温度高而改变,但夏季遮荫措施还是有必要的。

Diurnal Variation of Photosynthesis of Rhododendron fortunei in Two Kinds of Illumination Intensity under Low Altitude

The diurnal variation of photosynthesis of wild Rhododendron fortunei introduced at low altitude area under 10%light and full light was measured using LI-6400 portable photosynthesizer.The results showed that the transpiration rate of R.fortunei under 10%light was lower than that of full light,while water utilization efficiency was 60.17%higher than that of full light.The diurnal variation of net photosynthetic rate and transpiration rate under two kinds of lights showed single peak.The decrease of net photosynthetic rate under full light was not caused by stomatal restriction,while it was caused by stomatal restriction under 10%light.Research suggested that the light-loving characteristics of R.fortunei were not changed for the high temperature in the introduction area and summer shading was still necessary.