3种芳香植物光合特性的比较研究

以香樟、白兰花和栀子花为试验材料,利用Li-6400型光合作用测定系统监测其叶片光合生理生态特性,并利用相关分析探讨了净光合速率和蒸腾速率与生理生态因子间的关系。结果表明:①白兰花叶片的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Cd)的日变化均呈不对称双峰曲线,具有明显的光合"午休"现象;香樟叶片的蒸腾速率(Tr)和气孔导度(Cd)的日变化呈单峰曲线,而净光合速率(Pn)的日变化均呈双峰曲线;栀子花叶片的净光合速率(Pn)和气孔导度(Cd)的日变化均呈不对称双峰曲线,蒸腾速率(Tr)的日变化呈单峰曲线;香樟和栀子花的光合"午休"现象不太明显。②3种芳香植物Pn、Tr、Cd和Ci的峰值出现时间不同步。③3种芳香植物的净光合速率日均值、气孔导度的日均值和蒸腾速率的日均值依次为白兰花>栀子花>香樟,但种间差异不显著;胞间CO2日变化中利用的CO2体积分数日均值依次为栀子花>白兰花>香樟,由此可见栀子花和香樟适应环境的能力比白兰花较强,生长发育稳定且易成活,在植物配置中应多利用栀子花和香樟。

Study on Photosynthetic Characteristics of 3 Fragrant Plants

The LI-6400 portable photosynthetic system was employed to measure the net photosynthetic rate(Pn),stomatal conductance(Cd),intercellular carbon dioxide concentration(Ci) and transpiration rate(Tr) of Cinnamomum camphora,Cardenia jasminoides and Magnolia denudata,which grew in potted landscape garden,in order to study and compare their photosynthetic characteristics.The results were as follows :(i)The curves of diurnal variation of Pn,Tr and Cd in leaves of Magnolia denudata,showed two peaks which indicated a remarkable photosynthetic ’midday depressions’;the diurnal variation of Tr and Cd of C.camphora were one-peak curve,and Pn of Cinnamomum camphora were two-peaks;the curves of diurnal variation of Pn and Cd in leaves of C.jasminoides showed two peaks and the diurnal variation of Tr of Cardenia jasminoides was one-peak curve;C.camphora and C.jasminoides had a not clear midday depression.(ii) The peak values of Pn,Cd,Ci and Tr of the three fragrant plants appeared asynchronous.(iii)The order of the average values of the three fragrant plants of Pn,Cd and Tr were M.denudata> C.jasminoides > C.camphora,there were no significant difference among them;The order of the average values of Ci was C.jasminoides> M.denudata> C.camphora,so C.jasminoides and C.camphora were adaptable more widely to environment density than that of M.denudate.