Application of visible and near-infrared spectroscopy to classification of Miscanthus species

The feasibility of visible and near infrared (NIR) spectroscopy as tool to classify Miscanthus samples was explored in this study. Three types of Miscanthus plants, namely, M. sinensis, M. sacchariflorus and M. fIoridulus, were analyzed using a NIR spectrophotometer. Several classification models based on the NIR spectra data were developed using line discriminated analysis (LDA), partial least squares (PLS), least squares support vector machine regression (LSSVR), radial basis function (RBF) and neural network (NN). The principal component analysis (PCA) presented rough classification with overlapping samples, while the models of LineLSSVR, RBFLSSVR and RBFNN presented almost same calibration and validation results. Due to the higher speed of LineLSSVR than RBFLSSVR and RBFNN, we selected the lineLSSVR model as a representative. In our study, the model based on lineLSSVR showed higher accuracy than LDA and PLS models. The total correct classification rates of 87.79 and 96.51%were observed based on LDA and PLS model in the testing set, respectively, while the lineLSSVR showed 99.42%of total correct classification rate. Meanwhile, the linLSSVR model in the testing set showed correct classification rate of 100, 100 and 96.77%for M. sinensis, M. sacchariflorus and M. fIoridulus, respectively. The linLSSVR model assigned 99.42%of samples to the right groups, except one M. fIoridulus sample. The results demonstrated that NIR spectra combined with a preliminary morphological classification could be an effective and reliable procedure for the classification of Miscanthus species.