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期 刊 ：生态学报 2008年 28卷 6期 页码：2504~2504～2510

关键词：蒙古栎；最大净光合速率；最大羧化速率；最大电子传递速率；磷酸丙糖利用率；光合参数；土壤含水量；

Keywords:Quercus mongolica, maximum rate of net photosynthesis, maximum rate of carboxylation, maximum potential rate of electron transport, triose phosphate utilization rate, photosynthetic parameter, soil moisture,

摘 要 ：针对当前植物光合机理模型中植物光合参数没有考虑干旱胁迫影响的不足，以东北地区蒙古栎为研究对象，基于蒙古栎对不同水分响应的植物生理生态模拟试验，探讨了蒙古栎光合参数对水分胁迫的定量响应。结果表明，水分胁迫严重影响蒙古栎叶片的光合参数。其最大净光合速率（Pmax）与土壤含水量呈抛物线关系（P<0.01），且在土壤体积含水量35.45%(相当于土壤质量含水量23.63%)接近田间持水量（27.4%）时达到最大值。蒙古栎幼苗叶片的最大羧化速率（Vcmax）、最大电子传递速率（Jmax）和磷酸丙糖利用率（TPU）均与土壤水分呈抛物线关系（P<0.01），即Vcmax、Jmax 、TPU对土壤水分具有相同的响应趋势，但各光合参数达到最大时的土壤水分阈值却不相同。同时，基于蒙古栎光合作用参数对水分变化响应的定量分析，建立了水热因子协同影响的植物光合参数模型，为最终建立适用于所有植物的水热因子协同影响的光合参数模型提供了依据与技术示范。

Abstract:Considering that the effects of drought on plant photosynthetic parameters have not been quantitatively described in plant mechanistical photosynthesis models, the seedlings of Quercus mongolica from northeast China were used as a case study to analyze the responses of its photosynthetic parameters to different soil water contents. The results showed the relationship between the maximum net leaf photosynthesis rate (Pmax) of Quercus mongolica and soil moisture could be expressed as a quadratic curve (P<0.01), and Pmax reached a maximum when soil volume water content was 35.45% close to field water holding capacity. The maximum rate of carboxylation(Vcmax), the maximum potential rate of electron transport(Jmax) and triose phosphate utilization rate(TPU) of Quercus mongolica also had quadratic relationships with soil water content (P<0.01).Namely，Vcmax、Jmax 、TPU had similar response curves to soil water, but had different optimal soil water contents .This function based on the temperature and water responses of plant photosynthetic parameters provides the researchers with the parameters and methodology for understanding and simulating the responses of plant photosynthetic parameters to drought stress.

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