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作 者 ：杨晓盆,张 超,王文梅,张旺军.

期 刊 ：中国生态农业学报 2008年 16卷 4期 页码：909-913

关键词：扁核木；光合速率；气孔导度；蒸腾速率；表观量子效率；

Keywords:Primula maximowiczii Batal., Photosynthetic rate, Stomatal conductance, Transpiration rate, Apparent quantum yield,

摘 要 ：用Li-6400光合作用测定系统对扁核木的光合特性进行了测定。结果表明：扁核木叶片光合速率日变化呈双峰曲线，最高峰分别出现在10:00和15:00，有明显的光合“午休”现象；叶片蒸腾速率和气孔导度的日变化趋势与光合速率相似，呈双峰曲线。光合速率与气孔导度、蒸腾速率呈极显著正相关；影响光合作用的主导环境因子为光合有效辐射和相对湿度。扁核木光合作用的光饱和点和补偿点分别为1 020 μmol·m^-2·s^-1和23.8 μmol·m^-2·s^-1，表观量子效率为0.056 9；CO₂饱和点和补偿点分别为1 330 μmol·mol^-1和54.7 μmol·mol^-1，羧化效率为0.072 4；光合作用最适温是24.9 ℃。扁核木净光合速率的季节性变化也呈双峰曲线。

Abstract:The photosynthetic characteristics of Prinsepia uniflora Batal. were examined by using Li-6400 Portable Photosynthesis System. The results indicate that the diurnal curve of photosynthesis rate (Pn) of P. uniflora leaf presents two peaks, and the fist peak appeares at 10:00 ,and sub-peak at 15:00, with an obvious mid depression. The diurnal curves of leaf transpiration rate and stomatal conductance are similar to Pn, with two peaks too. Pn is significantly positive related with transpiration rate and stomatal conductance.The principal environmental factors affecting Pn are photosynthetic active radiation and relative humidity. The light saturation point and light compensation point of P. uniflora are 1 020 μmol·m^-2·s^-1 and 23.8 μmol·m^-2·s^-1 respectively, while the apparent quantum yield is 0.056 9. The CO₂ saturation point and CO₂ compensation point are 1 330 μmol·mol^-1 and 54.7 μmol·mol^-1 respectively, while the carboxylation efficiency is 0.072 4. The optimal leaf temperature of photosynthesis is 24.9℃. The seasonal variation of Pn presents a two peak curve too.

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