为了利用杜鹃花的生理生态特性高效率地建设深圳梧桐山风景区的“十里杜鹃”景点,研究了该景区引种栽培的毛棉杜鹃、华丽杜鹃、映山红的光合特性参数.结果表明:毛棉杜鹃的净光合速率(Pn)为双峰曲线,出现光合“午休”现象；华丽杜鹃和映山红的Pn是单峰曲线.净光合速率的日均值由大到小的顺序为:毛棉杜鹃、华丽杜鹃、映山红.3种杜鹃的蒸腾速率(Tr)均为单峰曲线,华丽杜鹃的蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2摩尔分数显著高于毛棉杜鹃和映山红.在水分利用率和光能利用率方面,毛棉杜鹃显著高于华丽杜鹃和映山红.因此,毛棉杜鹃可作为上述景点建设的优先选择种.%Diurnal changes in photoaynthetic characteristics of the leaves of Rhododendron moulmainense Hook. f. , R. eudoxum Barf. f. et Forrest and R. simsii Planch, were measured with the aid of Li-6400 portable photosynthesis system. Result showed that the net photosynthetic rate of R. moulmainense presented a double-peak curve with a midday depression; while that of R. eudoxum and it simsii both exhibited a single-peak curve. Moreover, the average net photosynthetic rate of R. moulmainense was the highest, followed by R. eudoxum and R. simsii. The transpiration rate of all the Rhododendron culti-vars appeared a single-peak curve. The transpiration rate, stomatal conductance, and intercellular CO, concentration of R. eudoxum were markedly higher than those of the other cultivars. However, the water use efficiency and light use efficiency of R. moulmainense was the highest. In conclusion, R. moulmainense is the best cultivar for the construction of scenic spots due to its high net photosynthetic rate, water use efficiency, and light use efficiency.
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