氮胁迫下水稻的激光诱导荧光光谱特性

为了指导水稻的田间施肥，解决因过量施肥造成资源的大量浪费以及环境污染，特别是水体富营养化等问题，搭建了基于紫外激光诱导荧光技术的荧光光谱探测系统，以研究水稻叶片的氮水平与荧光强度的相关性。文中先用植物营养测定仪(TYS-3N)测定水稻叶片氮含量和叶绿素含量（样本为水稻分蘖期的倒二叶，采集于中国江汉平原地区），再用搭建的测量系统采集了不同氮水平的荧光光谱。获得了不同氮水平下水稻叶片的荧光光谱数据库，分析了荧光光谱参数F₇₄₀/F₆₈₅（为峰值740，685 nm处的荧光强度比）与氮水平的相关性，发现氮含量的变化对水稻叶片荧光光谱特性影响明显。通过该实验验证了荧光参数的峰值比F₇₄₀/F₆₈₅与氮含量呈明显的线性正相关，相关系数（r）为0.871 8，均方根误差（RMSE）为0.076 82。实验表明采用激光诱导荧光光谱探测技术具有快速无损等优点，且有一定潜力用于定量测量植被营养元素的含量，为采用荧光技术对农作物施氮管理提供了支持。

Laser Induced Fluorescence Spectrum Characteristics of Paddy under Nitrogen Stress

Order toguide fertilizing andreduce waste of resources as well as enviro nmental pollution ,especially eutrophication , which are caused by excessive fertilization ,a system of laser-induced fluorescence(LIF) was built .The system aimed to investi-gate the correlation between nitrogen (N) content of paddy leaf and the fluorescence intensity .We measuredNcontent and SPAD of paddy leaf (the samples came from the second upper leaves of paddy in tillering stage and the study area was located in Jiang-han plain of China) by utilizing the Plant Nutrient (Tester TYS-3N) .The fluorescence spectrum was also obtained by using the systembuilt based on theLIFtechnology .Fluorescence spectra of leaf with different N-content were collected and then a fluores-cence spectra database wasestablished .It is analyzed that the relationship between the parameters of fluorescence (F740/F685 is the ratio of fluorescence intensity of 740 nm dividing that of 685 nm) and the N level of paddy .It is found that the effect of different N-content on the fluorescence spectrum characteristics is significant .The experiment demonstrated the positive correlation be-tween fluorescence parameters and paddy leaf N-content .Results showed a positive linear correlation between the ratio of peak fluorescence (F740/F685 ) and N-content .The correlation coefficient (r) reached 0 .871 8 and the root mean square error (RMSE) was 0 .076 82 .The experiment demonstrated that LIF spectroscopy detection technology has the advantages of rapidand non-de-structive measurement ,and it also has the potential to measure plant content of nutrient elements .It will provide a more accurate remote sensing method to rapidly detect the crop nitrogen levels .