| 摘要: |
| [目的]植物光合作用对CO2的响应是光合作用研究的重要内容,当前应用广泛的Michaelis-Menten 模型拟合所给出的植物光合能力远大于实测值,而所给出的饱和CO2浓度远小于实测值,欲引入新模型解决上述问题.[方法]用构建的光合作用对CO2浓度响应的新模型,拟合了丹参的CO2浓度响应测量数据,并研究了低CO2浓度条件下,丹参净光合速率对CO2浓度的响应及羧化效率在CO2补偿点附近的改变情况.[结果]用CO2响应新模型拟合丹参的实测数据,在不需作其他附加假设条件下就可以给出丹参的饱和CO2浓度、光合能力、光呼吸速率、CO2补偿点及在CO2补偿点的羧化效率,且拟合结果与实测结果符合很好(R2=0.999 6).[结论]在低CO2浓度条件下,丹参植物叶片的净光合速率对CO2浓度的响应为非线性的;在CO2补偿点附近,羧化效率并非常数,而是随CO2浓度的增加而减小. |
| 关键词: 丹参：新模型 CO2补偿点 光合能力 饱和CO2浓度 |
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| 基金项目:江西省科技厅农业攻关项目(吉市科技字［2006］21号) |
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| Change of carboxylation efficiency of Salvia miltiorrhiza in the vicinity of CO2 compensation point |
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| Abstract: |
| 【Objective】 It is important to study the CO2 response curve of leaf net photosynthesis.The values of photosynthetic capacity calculated by most extensively applied Michaelis-Menten model are much higher than measured values, and the saturation CO2 concentration much lower than the measured values.These problems can be resolved by a new model of CO2 response curve of leaf net photosynthesis.【Method】 A new model of CO2 response curve of leaf net photosynthesis was given here,and data from CO2 response experiment of Salvia miltiorrhiza was simulated.The response of photosynthetic rate to CO2 concentration of S.miltiorrhiza under low CO2 concentration and change of carboxylation efficiency in the vicinity of CO2 compensation point were discussed in detail.【Result】 The main photosynthetic parameters,i.e.the saturation CO2 concentration,photosynthetic capacity,photorespiration rates and CO2 compensation point of S.miltiorrhiza were calculated by the new model without any additional hypotheses.【Conclusion】 The fitted results show that photosynthetic response to CO2 concentration was nonlinear under low CO2 concentration.The carboxylation efficiency was not a constant in the vicinity of CO2 compensation point,and it decreased while CO2 intercellular concentration increased. |
| Key words: Salvia miltiorrhiza new model CO2 compensation point photosynthetic capacity saturation CO2 concentration |
