Cu胁迫下叶片日光诱导荧光辐射特征研究

农作物在重金属铜胁迫下生长,日光诱导荧光辐射特征会发生变化,可以间接地反映植被受重金属胁迫的强度。在本研究中,采用不同铜浓度的污染土壤作为培养基,选取双子叶作物油菜进行铜胁迫生长实验,获取4个不同生育期以及7个不同铜污染强度下的植被叶片的反射光谱。基于叶片荧光光谱特征,采用PROSPECT模型反演方法从油菜叶片反射光谱中获得不同铜胁迫下油菜叶片的荧光光谱,提取荧光光谱峰值特征,并根据油菜不同的生长时期建立了红荧光峰值与叶片中铜含量之间的负相关关系。验证了提取荧光光谱方法的可行性,为大面积植被重金属含量检测提供理论依据。

Study for rape leaf solar-induced fluorescence under Cu stress

When the crops grow under Cu stress, we can use the changed leaf-level solar-induced fluorescence to estimate the stress level. In this study, rape was selected and cultured with Cu polluted soil. The reflectance of leaves was measured by an ASD Fieldspec spectrometer for 4 times during the rape growth process. The rape leaf level solar-induced fluorescence were extracted from the apparent reflectance based on PROSPECT model. After finding the fluorescence peak value from rape solar-induced fluorescence under 7 level Cu stress, the relationship between Cu content and solar-induced fluorescence was obtained, and a negative correlation was found between the peak value of RED fluorescence and the Cu contents in leaves. This feasibility extraction method was verified to get the characteristic peak value at different time during the vegetation growing season, which can provide the theoretical basis for the heavy metal content extracting of large areas.