Abstract: [Objective] To understand the effect of different temperatures on the SPAD value of cotton leaves,the SPAD value of leaf was retrieved by hyperspectral data during the blossoming and boll-forming period.[Method]The statistical methods,such as the correlation analysis and linear regression,were used to analyze the relationship between SPAD value,original spectra,first-order differential spectra and hyperspectral parameters.[Result]It was shown that the SPAD and original spectral reflectivity of the leaf would decrease with the rising temperature.The SPAD value was correlated to the original spectra,first-order differential spectra and hyperspectral parameters.After the overall comparison of correlation coefficient,adjusted R2 and the optimization of mean relative error,the optimal estimation mode for the SPAD value,original spectra,first-order differential spectra and hyperspectral parameters were built,with the correlation coefficient being 0.81,0.857 and 0.833,the adjusted R2 being 0.747,0.844 and 0.824 as well as the mean relative error being 9.12;,5.78;and 7.72;.The model built through the combination of the first-order differential spectra 671 nm and 683 nm(Y=50.487 X683-131.617 X671+36.777)can achieve the highest accuracy in predicting the SPAD value,followed by the hyperspectral parameter and original spectra.[Conclusion]As shown by the experimental results,the hyperspectral sensing information can provide the theoretical basis for predicting the SPAD value for the cotton leaf during the blossoming and boll-forming period.

摘要： [目的]研究不同温度对棉花叶片SPAD值的影响,利用高光谱反演叶片SPAD值.[方法]以不同温度处理花铃期水培棉花叶片为材料,利用美国SVC-HR768光谱仪测定叶片光谱反射率和SPAD502叶绿素计测定叶片SPAD值,采用相关分析、线性回归等方法,分析叶片SPAD值与原始光谱、一阶微分光谱和高光谱参数数据之间的关系.[结果]随着温度的升高,叶片SPAD值和原始光谱反射率逐渐下降,叶片SPAD值与原始光谱、一阶微分光谱和高光谱参数数据均具有较好的相关性,通过相关系数、调整R2和平均相对误差最大优选原则综合比较,筛选建立的叶片SPAD值与原始光谱、一阶微分光谱和高光谱参数的较优估测模型,相关系数分别为0.81、0.857和0.833,调整R2分别0.747、0.844和0.824,平均相对误差分别为9.12;、5.78;和7.72;.[结论]一阶微分光谱671和683 nm组合波段构建的模型Y=50.487 X683-131.617 X671+36.777预测叶片SPAD值最为精确,高光谱参数次之,原始光谱最差,为利用高光谱遥感信息反演花铃期棉花叶片SPAD值提供理论依据.