重金属锌胁迫的白菜叶片光谱响应研究

Study on the Spectrum Response of Brassica Campestris L Leaf to the Zinc Pollution

在实验室土培条件下,应用白菜（Brassica Campestris L.）叶片红边位（680-740 nm）、可见区光谱（460-680 nm）、近红外区光谱（750-1000 nm）三种特征光谱因子研究了重金属锌对白菜生长的胁迫响应。随土壤中Zn含量增加,白菜叶片金属Zn富集程度逐渐增大,白菜叶片叶绿素含量降低;随白菜叶片Zn含量增加,白菜叶片光谱的可见区反射率变化程度（A1）增加,白菜叶片光谱近红外区反射率变化程度（A2）降低,红边“蓝移”（向短波方向飘移）程度（S）逐渐增强。应用A1,A2,S作参数对白菜叶片Zn含量对数值（lnCL,CL单位为mg·kg^-1）进行定量线性相关分析,三模型复相关系数r2分别为0.942,0.981和0.969,三种特征光谱因子能够用来预测白菜叶片金属Zn含量。

In the present paper,the spectrum response of Brassica Campestris L leaf to the stress of heavy metal zinc pollution was studied in three spectral rangess of the red edge position（680-740 nm）,the visible spectrum（460-680 nm） and the near infrared spectrum（750-1 000 nm）.The results indicate that the Zn content in cabbage leaves increases and the chlorophyll level reduces with the increase in Zn concentration in soil.With the Zn content of Brassica Campestris L leaves increasing,the leaf spectral reflectivity in visible light（A1） and the range of red edge shift（S） ascends,the the leaf spectral reflectivity in the near infrared light（A2） decreases.The three indices of A1,A2 and S are fitted much linearly with the logarithm of zinc content in Brassica Campestris L leaves with the high squared regression coefficients of 0.942,0.981 and 0.969 respectively.The regression models are reliable to estimate the zinc content in Brassica Campestris L leaves.