不同氮素条件下米槁光响应曲线拟合模型的比较分析

Comparison and Analysis of Fitting Models of Photosynthesis and Light Response Curve of Cinnamomum migao under Different Nitrogen Fertilizer Conditions

分析了施氮量对米槁幼苗光响应曲线的影响。采用砂培法,设置4种不同的氮素浓度,利用直角双曲线模型、非直角双曲线模型、直角双曲线修正模型等6种模型对米槁叶片进行光响应曲线拟合。此外,也对相关光合参数的响应过程做了探讨。结果表明,在不同氮素处理下,修正模型拟合的各项光合参数结果与实测值比较接近。其中,在N3处理下,米槁幼苗LSP(1 722.041μmol·m^(-2)·s^(-1))、Pnmax(8.295μmol·m^(-2)·s^(-1))、AQE(0.027μmol·m^(-2)·s^(-1))均大于其他处理,LCP(13.769μmol·m^(-2)·s^(-1))小于其他处理;且随着施氮量的增加,米槁叶片叶绿素含量、净光合速率Pn、气孔导度Gs、蒸腾速率Tr呈增大的趋势,胞间CO_2浓度Ci呈下降的趋势。因此,增施氮量能够显著改变米槁对光的适应幅度,提高叶片光能利用率。

In order to explore the effect of nitrogen fertilizer on light response curves of Cinnamomum migao seedlings, sand culture of the seedlings was adopted, in which different nitrogen concentrations were set up. Six models were used to fit the light response curve of C. migao leaves under different nitrogen treat- ments, including the rectangular hyperbola model, the non-rectangular hyperbola model, the rectangular hy- perbola modified model, etc. In addition, the response process of photosynthetic parameters were discussed. The results showed that under different nitrogen treatments, the rectangular hyperbola modified model was mostly closed to the measured data,in which under Na treatment,the values of the C. migao seedlings＇ LSP （1 722.041 μmol·m-2·s-1）,P （8. 295μmol·m-2·s-1）,and AQE（0. 027μmol·m-2·s-1） were higher than other treatments,LCP（13. 769 μmol·m-2·s-1） was less than other treatments. With the increase of nitrogen fertilizer, Chl, Pn,Gs and Tr of the seedlings increased, while Ci decreased,indicating that the increase of nitrogen fertilizer could change the light adaptation scope of C. migao,and improve leaf energy utilization rate.