药用植物艾纳香光合光响应曲线及其模型拟合

为了探明艾纳香光响应特征及其最大净光合速率、光饱和点等光合参数,从而为艾纳香优质苗木的培育及科学栽培提供理论依据,采用Li-6400光合作用测定系统对艾纳香一年生苗木叶片光响应进行了测定,并应用4种光响应经验模型对艾纳香叶片光响应曲线进行拟合。结果表明:1)直角双曲线、非直角双曲线及指数函数模型不能求取艾纳香最大净光合速率和光饱和点的解析解,而结合其他方法拟合的相应值与实测值有显著差异,同时也不能处理发生光抑制的光响应数据;2)修正的直角双曲线模型拟合的各项光合参数均比较准确,同时也能很好地处理艾纳香发生光抑制的光响应数据;3)经修正的直角双曲线模型拟合的艾纳香最大净光合速率、光饱和点、光补偿点、暗呼吸速率和初始量子效率分别为19.00μmol/(m2.s)、1 866.15μmol/(m2.s)、33.56μmol/(m2.s)、-2.07μmol/(m2.s)和0.066。结论:艾纳香光能利用能力和光合生产力较高,有一定的耐阴能力,对光照的适应范围较宽。

Photosynthetic Light Response Curve of Blumea balsamifera and Its Model Fitting

The leaf light response curve of annual B.balsamifera seedlings was measured by Li-6400 portable photosynthesis system and then the obtained leaf light response curve was fitted by using four empirical light response models to explore the light response characteristics and the photosynthetic parameters of maximum net photosynthetic rate,light saturation point for scientific culture and cultivation of B.balsamifera seedlings.The results showed that: 1)The analytical solution of maximum net photosynthetic rate and saturation point of B.balsamifera couldn’t be solved by rectangular hyperbola model,non-rectangular hyperbola model and index function model.There was significant difference between the measured value and the simulated values by other methods,and the data under photo-inhibition also couldn’t be processed by the three models.2) The photosynthetic parameters simulated by modified rectangular hyperbola model were all close to the measured values,and the modified rectangular hyperbola model also could well process the light response data under photo-inhibition of B.balsamifera.3) The maximum net photosynthetic rate,light saturation point,compensation point,respiration rate and initial quantum efficiency of B.balsamifera simulated by modified rectangular hyperbola model were 19.00 μmoL(m2·s),1 866.15 μmoL(m2·s),33.56 μmoL(m2·s),-2.07 μmoL(m2·s) and 0.066 respectively.In conclusion: B.balsamifera with high light use capability,high photosynthetic productivity and a certain shade tolerance had a wider adaptation capacity to light intensity.