铅离子胁迫下盆栽玉米叶片光谱微分的红边响应研究

基于重金属铅(Pb)污染的盆栽实验玉米,采用光谱仪和叶绿素仪测量了不同浓度Pb~(2+)胁迫下玉米老、中、新叶片的反射光谱及其叶绿素含量;也运用质谱仪测定了不同胁迫浓度叶片中Pb~(2+)含量。对玉米老、中、新叶片中的叶绿素含量与各类叶片及土壤中的Pb~(2+)浓度进行了相关性分析;并为了区分玉米叶片铅离子污染程度和预测Pb~(2+)含量,提出了红边一阶微分曲线面积比值(FARR)和红边一阶微分峰前面积(FABR)参数;同时与常规红边一阶微分包围面积(FAR)、红边一阶微分曲线陡峭度(FCDR)、红边位置(REP)以及红边最大值(MR)作运用比较,实验结果表明,玉米叶片中的叶绿素含量从新叶、中叶到老叶逐渐增加,并随着土壤中Pb~(2+)浓度的升高而降低;受到Pb~(2+)胁迫时,新叶片到老叶片的REP"蓝移"更为明显;FARR和FABR在Pb~(2+)的胁迫程度区分和污染监测方面比FAR、FCDR、REP、MR具有更好的预测效果。

Study on the Red edge Response on Derivative Spectra of Potted corn leaves Stressed by Lead ions

_{Based on the potted corn experiment polluted by heavy metal lead (Pb), the reflectance spectra and chlorophyll contents of old, middle, new corn leaves stressed by the different concentrations of Pb2+ were measured by the spectrometer and chlorophyll meter, furthermore Pb2+contents in the each stressed concentration level were measured by the mass spectrometer. The relationships were analyzed between the chlorophyll contents in the old, middle, new corn leaves and Pb2+concentrations in the different type leaves and the soil in the paper. In addition, In order to distinguish the degree of Lead ions pollution and predict Pb2+content of corn leaves, the paper proposed First derivative Area Ratio of Red-edge(FARR) and First derivative Area before Ratio of Red edge(FABR) parameters, at the same time they were used to compare with the conventional methods such as the first derivative area of red edge(FAR), first derivative curve steep degree of red edge(FCDR), red edge position(REP) and the maximum value of red edge(MR), the experimental result shows that, the chlorophyll content in corn leaves was gradually raised from the new to the middle and old leaves, and the chlorophyll content in the leaves would be reduced with the increase of Lead ions concentration in the soil, the blue move of REP was more obvious from the new to the old leaves when stressed by Pb2+, FARR and FABR has better predicting effects than FAR, FCDR, REP and MR in distinguishing stress degree of Lead ions and Pollution monitoring.}