Abstract: The hyperspectral reflectances of the canopy, the first and the third unfolding leaf from the top and panicles of two rice varieties were measured by a ASD FieldSpec Pro FR TM in field and indoor under three nitrogen levels at different developmental stages.The concentrations of chlorophyll and carotenoid in leaves and panicles corresponding to the spectra were determined by biochemical method. The spectral differences were significant for the canopies and leaves of rice under different nitrogen levels, and the concentrations of chlorophyll and carotenoid of leaves increased along with nitrogen application increased. There were significant differences in the pigment concentrations of the rice leaves under different nitrogen levels. The spectral reflectance of the canopy was gradually getting smaller in the visible region and bigger in the near infrared region as the growth stages goes on before heading stage, but with reverse change after heading stage. There existed “blue shift” phenomena for the position of red edge of the spectra of canopies, leaves and panicles after heading stage. The concentrations of chlorophyll and carotenoid of leaves presented S-shape change. The concentrations of chlorophyll and carotenoid of canopies, leaves and panicles were very significantly correlative to the hyperspectral vegetation indices R₉₉₀/R₅₅₃, R₁₂₀₀/R₅₅₃, R₇₅₀/R₅₅₃, R₅₅₃/R₆₇₀, R₈₀₀/R₅₅₃, PSSRa (R₈₀₀/R₆₈₀), PSNDa[(R₈₀₀-R₆₈₀)/(R₈₀₀+R₆₈₀)][R denotes reflectance, number in subscript is wavelength (nm)] and the red edge position λ red. This indicated that these vegetation indices could be used to estimate the concentrations of chlorophyll and carotenoid of canopies, leaves and panicles of rice.

Key words: hyperspectral reflectance, chlorophyll, carotenoid, vegetation index, rice, developmental stage

摘要： 通过大田和室内试验，测定了2个品种、3个供氮水平处理的水稻冠层、完全展开倒1叶、倒3叶和穗在不同发育时期的高光谱反射率及对应叶片和穗的叶绿素、类胡萝卜素含量。结果表明，不同供氮水平的水稻冠层和叶片光谱差异明显，冠层光谱反射率随发育期推迟,抽穗前在可见光范围逐渐降低、在近红外区域逐渐增大，抽穗后在可见光范围逐渐增大，在近红外区域逐渐降低；抽穗后，冠层、叶片和穗光谱的红边位置存在“蓝移”现象；叶片叶绿素、类胡萝卜素含量呈S形变化；高光谱植被指数R990/R553、R1200/R553、R750/R553、R553/R670、R800/R553、R800/R680、（R800-R680）/（R800+R680）［R为反射率，下标为对应波长值（nm)］和红边位置λred与叶绿素、类胡萝卜素含量之间存在极显著相关，说明能用它们来估算水稻冠层、叶片和穗的叶绿素、类胡萝卜素含量。

关键词: 高光谱反射率, 叶绿素, 类胡萝卜素, 植被指数, 水稻, 发育时期