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| Diagnostic models research for Cd stress of rice based on canopy multi-dimensional spectra |
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Abstract The variation of physiological characteristic parameters in Cd -induced stress on rice is complex and unobvious, which lead to subtle changes in spectral curve shape. Some methods were used to enhance and extract subtle spectral feature information associated with heavy metal pollution. Hyperspectral data of rice canopy and biochemical parameters were measured. Three methods were used, namely principal component analysis (PCA), independent component analysis (ICA) and fractal analysis. Spectral parameters sensitive to Cd contamination, namely F1, ICA1 and fractal dimension of spectral reflectance (D), were obtained by different methods. The above sensitive factors were used to establish one-dimensional diagnosis model for rice under Cd contamination with satisfactory results. The correlation coefficient (R2) between three sensitive spectral parameters and Cd concentration were above 0.8. In addition, stable, sensitive and visual diagnostic methods were achieved by two-dimensional and three-dimensional diagnostic models with three diagnostic indicators. Multi-dimensional spectral diagnostic models can provide an effective way to monitor rice under Cd Stress comprehensivly, systematically on a large scale.
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Received: 07 May 2010
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