乐昌含笑幼苗在不同光照环境下的光响应模型拟合分析

Fitting Analysis of Light Response Models of Michelia chapensis Seedlings Under Different Light Environments

摘要:

为探究不同光强下乐昌含笑(Michelia chapensis)光响应特征及光响应模型的适用性，以乐昌含笑1 a生幼苗为试材, 设置5种光强100%、70%、50%、30%、10%全光照处理，测定其光响应曲线，并采用直角双曲线模型(RH)、非直角双曲线模型(NRH)、指数模型(EM)、修正直角双曲模型(MRH)及修正指数模型(MEM) 5种模型对其进行拟合，进而利用R_a²、均方误差(MSE)、平均绝对误差(MAE)结合光合参数实测值与拟合值对5种模型拟合效果进行综合评价。结果表明，应用RH、NRH和EM模型拟合不同光强下乐昌含笑光响应曲线不符合其光合-光响应特征；MRH模型拟合的各项光合参数与实测值最为接近，MEM模型次之。因此，MRH模型具有较高的拟合精度和适用性，是拟合不同光强下乐昌含笑幼苗光合-光响应特征的最适模型。

关键词:乐昌含笑;光照强度;光合作用;光响应曲线;光响应模型

Abstract:

To elucidate the light response characteristics and the applicability of the light response model of Michelia chapensis under different light intensities, one-year-old M. chapensis seedlings were grown under five light intensities, including 100%, 70%, 50%, 30% and 10% of nature light. The light response curves were measured and fitted by five models, such as rectangular hyperbola model (RH), nonrectangular hyperbola model (NRH), exponential model (EM), modified rectangular hyperbola model (MRH) and modified exponential model (MEM). Then, the fitting effects of the five models were comprehensively evaluated by using R_a², MAE and MSE combined with the measured values and fitting values of photosynthetic parameters. The results showed that the light response curves of M. chapensis under different light intensities fitted by RH, NRH and EM model did not conform to its photosynthetic-light response characteristics. The photosynthetic parameters fitted by the MRH models were the closest to the measured values, followed by the MEM model. Therefore, the MRH model has high fitting accuracy and applicability and is the most suitable model for fitting the photosynthetic light response characteristics of M. chapensis under different light intensities.

Key words:Michelia chapensis;Light intensity;Photosynthesis;Light response curve;Light response model