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作者	单位
康华靖，段世华，安婷，叶子飘	（1.温州市农业科学研究院,浙江温州 325006 2.浙南作物育种重点实验室，浙江温州 325001；3.井冈山大学生命科学学院,江西吉安 343009 4.井冈山大学数理学院,江西吉安 343009）

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中文摘要:

在Farquhar、von Caemermer和Berry模型(以下简称FvCB生化模型)中有2个子模型，即非直角双曲线模型和核酮糖-1,5-双磷酸(RuBP)再生速率限制模型，用其可以估算C₃植物叶片的最大电子传递速率(J_max)。为了严格验证由这2个子模型估算植物叶片J_max的精确度，本研究用LI-6400-40光合测定仪分别测定了2%和21% O₂ 浓度下小麦(Triticum aestivum L.)叶片的光合速率和电子传递速率对光和CO₂的响应曲线，并用此2个模型分别拟合了21%O₂浓度下小麦光合速率对CO₂的响应曲线和电子传递速率对光的响应曲线。结果表明，由非直角双曲线模型拟合小麦电子传递速率对光的响应曲线得到的J_max为254.86 μmol·m^-2·s^-1，显著高于其观测值(236.37 μmol·m^-2·s^-1)(P<0.05)；由RuBP再生速率限制子模型拟合小麦光合速率对CO₂的响应曲线得到的J_max为260.58 μmol·m^-2·s^-1，则显著低于其观测值(298.05 μmol·m^-2·s^-1)(P<0.05)。此外，当胞间CO₂浓度(C_i)为738.01 μmol·mol^-1时，小麦处于RuBP再生速率限制阶段，此时其净光合速率及其相应的光呼吸速率分别为61.16和8.55 μmol·m^-2·s^-1。在不考虑其他路径消耗光合电子的情况下，小麦在该C_i时同化这些碳至少需要光合电子流为352.24 μmol·m^-2·s^-1，这与由RuBP再生速率限制子模型估算的J_max(260.58 μmol·m^-2·s^-1)之间存在显著差异(P<0.05)。这说明非直角双曲线模型和RuBP再生速率限制子模型在估算小麦叶片J_max上存在缺陷，有待改进。

英文摘要:

Both the non-rectangular hyperbolic model and ribulose-1,5-disphosphate(RuBP) regeneration limitation model are the two main sub-models of the FvCB model,which are used to estimate the maximum electron transport rate(J_max) of wheat(Triticum aestivum). The two sub-models have been widely applied to fit the light-response curves of electron transport rate(J-I curves) and CO₂-response curves of photosynthesis,and obtain J_max. However,it has not been strictly verified whether J_max calculated by the two models are consistent with the observed values. Light-response curves of electron transport rate and CO₂-response curves of photosynthesis of wheat under 2% and 21% O₂ concentrations were simultaneously measured by LI-6400-40,and these data of 21% O₂ concentration were simulated by the two models. The results showed that the J_max estimated by non-rectangular model was 254.86 μmol·m^-2·s^-1,and the observation was 236.37 μmol·m^-2·s^-1,and the J_max estimated by RuBP regeneration limitation model was 260.58 μmol·m^-2·s^-1,and the observation was 298.05 μmol·m^-2·s^-1. There were significant differences between J_max estimated by the two models and the corresponding observation data(P<0.05). Moreover,wheat was under RuBP regeneration limitation while C_i equaled to 738.01 μmol·mol^-1,and its net photosynthetic rate was 61.16 μmol·m^-2·s^-1 and its photoresporatory rate was 8.55 μmol·m^-2·s^-1. When other pathway of consumption photosynthetic electron was neglected,the minimum photosynthetic electrons should be 352.24 μmol·m^-2·s^-1,which was larger than that of 260.58 μmol·m^-2·s^-1 estimated by the RuBP regeneration limitation model. Therefore,it can be concluded that J_max estimated by non-rectangular hyperbolic model and RuBP regeneration limitation model did not meet the photosynthetic electrons needed for carbon assimilation,which need to be further improved.

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