云南绿化树种滇润楠光合速率的研究

试验材料取自于云南昆明市西南林业大学绿化树种滇润楠,应用LI-6400便携式光合测定仪对滇润楠叶片的阳面叶片和阴面叶片的光合日进程及光响应曲线进行了测定.结果表明,净光合速率与光强,气孔导度和胞间CO2浓度大多呈多项式正相关关系.在光强为2000 μmol·m-2·s-1时,阳生叶的净光合速率为5 μmolCO2·m-2·s-1,在光强1500 μmol·m-2·s-1左右阴生叶的净光合速率趋于饱和.阳面叶片的净光合速率的日变化呈单峰曲线,其峰值在中午13:00时,阴面叶片的净光合速率的日变化为双峰曲线,其峰值分别出现在中午11:00时和下午15:00时.

Study on Photosynthetic Rate of Machilus yunnanensiswasb of Urban Greening Tree Species in Yunnan

The daily course of net photosynthetic rate(Pn,μmolCO2·m-2·s-1) and light responding curves of Machilus yunnanensiswasb were determined through use of LI-6400 portable photosynthesis meter.The results showed Pn of Machilus yunnanensiswasb had conic polynomial relationship with photosynthetic advantageous radiation(PAR),stomatal conductance(Gs,molH2O·m-2·s-1),intercellular CO2 concentration(Ci,μmolCO2·mol-1).Pn of sunny leave reached 5 μmolCO2·m-2·s-1 when PAR was 2000 μmol·m-2·s-1 and Pn of shade leave reached the maximum when PAR was about 1500 μmol·m-2·s-1.The daily course of Pn of sunny leave was singlepeak curve and the peak occurred at 13:00.The daily course of Pn of shade leave was bimodal curve and two peaks appeared at 11:00 and 15:00.