珍稀植物香果树光合作用日进程初步研究

Preliminary Study on the Diurnal Variation of Emmenopterys henryi,a Rare Species

在自然条件下,对香果树幼树光合作用日进程的研究结果表明:夏季晴天净光合速率日进程曲线为"双峰"型,光合效率午间明显降低,主要由非气孔限制引起。应用逐步多元回归方法,得到净光合速率日变化的最优方程为:A=-137.5217-0.0076Q+0.2148Ca+0.2294RH-3.7208Ta+5.0365Tl。光响应及CO2响应测试进一步证明,强光下光抑制的发生是引起光合效率午间降低的重要原因。

The diurnal variation of photosynthesis of Emmenopterys henryi young tree under natural conditions was studied. The resuits were as follows： In summer fine days, the curves of diurnal variation of net photosynthetic speed had two peaks, which showed an obvious decline of photosynthetic efficiency at noon. It was principally caused by non-stomatal limitation. The most excellent equation of the diurnal variation of net photosynthetic speed was attained by the method of stepwise multiple-regression as follows： A = -137. 5217-0.0076Q ＋ 0. 2148Ca ＋ 0.2294RH-3. 7208Ta ＋ 5. 0365T1. The response tests of light and CO2 indicated that the light inhibition under strong light was the key cause for the decline of photosynthetic efficiency at noon.