Spectral Variations of Laser Induced Fluorescence from Plant Leaves Excited at 325 nm and 375 nm

Abstract

This work reports the features of laser-induced fluorescence spectra from plant leaves excited at each 325 nm and 375 nm. In a pothos (Scindapsus aureus) leaf with different chlorophyll content, a good correlation was seen between F685/F740 (Fluorescence peak ratio of 685 nm to 740 nm) and the chlorophyll content in both 325 nm and 375 nm excitation. The impacts of UV-B and ozone stress for the LIF spectra were also examined in peanut (Arachis hypogaea L.) leaves. As for UV-B stress, characteristics of LIF spectral variation were somewhat different in the two ways (325 nm, 375 nm). At 375 nm excitation, F685/F530 (fluorescence peak ratio of 685 nm to 530 nm) decreased against UV-B stress. At 325 nm excitation, on the other hand, the F685/F530 increased only at the first stage of UV-B stress, and gradually increased from middle to latter stages. This increment of the F685/F530 in 325 nm excitation was not observed with ozone stress. These results indicated that it is effective for accurate diagnoses of plant leaves to monitor the LIF spectra with different excitation wavelengths in UV region.