红麻和白麻光合特性研究

A study on photosynthetic characteristics of Apocynum Venetum L and Poacynum pictum Baill

用CIRAS-1便携式光合测定仪分别测定红麻和白麻的光合参数。结果表明:红麻和白麻的光合日变化均为典型双峰曲线,主峰值出现在上午10∶00左右,次峰出现在下午14∶00,具有明显的光合"午休"现象。红麻和白麻的净光合速率(Pn)随光合有效辐射(PAR)的增加而迅速升高,光补偿点(LCP)分别为84.9μmol/(m2.s)和85.8μmol/(m2.s),光饱和点(LSP)分别为1 860μmol/(m2.s)和1 618μmol/(m2.s)。红麻和白麻CO2补偿点分别为74.8μmol/mol和49.3μmol/mol;CO2饱和点分别为1 597μmol/mol和1 737μmol/mol,这表明白麻对高浓度的CO2适应能力和利用能力比红麻强。

The photosynthetic parameters of dogbane（including Apocynum venetum L and Poacynurn picture Baill）were measured with CIRAS- 1 portable photosynthesis system in the sunshine days of September, The results showed that the diurnal change of photosynthesis rate（ Pn ）of dogbane displays a double-peak manner thus suffering a noon inhibition. Their first peak occurred at 10：00 AM while the second peak appeared at 14：00 PM, The net photosynthetic rate（Pn ） of dogbane increases rapidly with the rising of Photosynthetic Active Radiation（PAR）. The light compensation point （LCP） of A. Venetum and P, picture are 84.9 μmol/（m^2 · s） and 85.8 μmol/（m^2·s） respectively for mature leaves, and the light saturation point（LSP） is 1 860 μmol/ （m^2·s） and 1 618 μmol/（m^2·s） respectively. The CO2 compensation point （CCP） of A. Venetum and P. picture is 74,8 and 49,3 μmol/（m^2·s）, respectively, and the CO2 saturation point（CSP） are 1 597 μmol/（m^2·s）, and 1 737 μmol/（m^2·s） , which demonstrates that P, picture is adapted to higher CO2 concentration than A. Venetum.