柽柳叶片光合速率日变化特征的研究

Study on the Daily Variations of Photosynthesis Rate in Leaves of Tamarix ramosissima

[目的]揭示典型天气下柽柳叶片光合特性的日变化规律。[方法]采用GSF-3000光合分析仪,对人工栽植自然条件下生长的5年生柽柳的光合作用日变化进行观察,并研究了生态因子与光合作用的关系。[结果]在典型晴天条件下,柽柳光合速率(A)日变化呈单峰曲线,12:30左右达到最大值,约为6.043μmol/(m2.s);柽柳蒸腾速率(E)的日变化为双峰曲线,最大值分别出现在12:30和15:30,分别为6.236和5.954 mmol/(m2.s)。应用相关分析和逐步多元回归分析方法建立了柽柳光合速率和蒸腾速率与大气CO2浓度、胞间CO2浓度、水汽压、水汽压亏缺等9项影响因子的回归方程,其相关系数分别为0.9900、.998。[结论]柽柳叶片的光合作用和蒸腾作用表现出不同的变化特征。

[ Objective] The purpose was to reveal the daily variation law of photosynthesis character of Tamarix rarnosissima under typical weather conditions. [Method] GSF-3000 photosynthesis analyzer was used to observe the daily variation of photosynthesis of 5-yeay-old T. rarnosissima grown under natural conditions of artificial plantation and study the relationship between the ecological factors and photosynthesis. [ Result] In the typical sunny days, the curve of daily variation of net photosynthetic rate was single-peak curve and its peak occurred at 12： 30 a. m., with the maximum value of 6. 043 mol/（m^2·s）. The curve of daily variation of transpiration rate was double-peaks and the peak appeared at 12：30 and 15：30, with the maximum values of 6.236 and 5.954 mmol/（m^2·s）, resp. By using the methods of correlation analysis and stepwise multi-regress analysis, the regress equation among the photosynthetic rate and transpiration rate with 9 environmental influencing factors such as atmosphere CO2 concn., intercellular CO2 concn., water air pressure and deficit of water air pressure was constructed, with their correlation coefficients being 0.990 and 0.998, resp. [ Conclusion] Photosynthesis rate and transoiration rate of T. ramosissima leaves showed different variations character.