| 摘要: |
| 【目的】探究玉米叶片SPAD值与其高光谱特征之间的品种差异，构建不同玉米品种叶片SPAD值估测模型，并对模型应用范围进行验证。【方法】通过大田试验，测定多个玉米品种叶片的SPAD值及其高光谱数据，利用相关分析及逐步回归分析等方法，构建和筛选玉米叶片SPAD值与相关光谱参数的回归模型，并利用偏差率对模型精度进行检验。【结果】不同玉米品种叶片的SPAD值与其高光谱反射率及一阶导数的相关波段存在差异，但品种间差异较小，关系最密切的波段均处于560和700 nm附近。对不同玉米品种的光谱反射率一阶导数进行比较时，出现“红移”现象，“红移”规律与各品种叶片SPAD值大小表现一致；叶片SPAD值与光谱反射率一阶导数的显著相关波段在510，615，690和740 nm附近。在构建估测模型时，以单波段光谱参数构建的模型估测效果较组合波段构建的模型好，且模型类型为多元方程和指数方程。以单一玉米品种叶片光谱参数建立的模型可以对其他玉米品种叶片的SPAD值进行估测，但估测精度在不同品种间存在差异。【结论】以高光谱560 nm附近波段反射率建立的模型精度最高，对不同品种的玉米叶片SPAD预测值偏差率普遍小于5.00%。 |
| 关键词: 玉米叶片 SPAD值 高光谱估测模型 品种差异 |
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| 基金项目:国家科技部粮食丰产科技工程项目（2011BAD16B13，2012BAD04B04，2013BAD07B04，2011BAD16B14）；国家玉米产业技术体系项目（CARS-02-63） |
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| Establishment and differences of high spectral estimation models for leaf SPAD values of different maize species |
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GAO Xin,GAO Jülin,YU Xiaofang,et al
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| Abstract: |
| 【Objective】This study explored the differences between leaf SPAD values of maize species and the hyper spectral feature,built the estimation models for SPAD values,and verified the application range.【Method】Through field experiment,this study measured the leaf SPAD values of multiple maize varieties and their hyper spectral data.By using the correlation analysis,stepwise regression analysis and other methods,regression models of SPAD values and related spectral parameters were constructed and screened.The accuracies of models were also tested using deviation rate.【Result】Leaf SPAD values of different maize varieties were different from high spectral reflectance and the first derivative of relevant band gap,while the differences among varieties were small.The closest relationships located near 560 and 700 nm.When comparing the first derivative of spectral reflectance between varieties,“red shift” phenomenon appeared,which was consistent in size with SPAD values.Leaf SPAD values and first derivative of spectral reflectance were significantly correlated near 510,615,690,and 740 nm.The model constructed by single band spectrum parameter was better than the model by combinational band,and the models were multiple and exponential equations.The built model with leaf spectral parameters of single maize can be used for other varieties with different accuracies.【Conclusion】The model established with hyper spectral band reflectance near 560 nm had the highest precision,and the deviation rate for predicting leaf SPAD values was generally less than 5.00%. |
| Key words: maize leaf SPAD value hyperspectral estimation model variety difference |
