Early Detection of Photosynthetic Dysfunction Caused by a Herbicide (Basta) Using Chlorophyll Fluorescence and Thermal Imaging System

抄録

　The effects of Basta, a commercially available foliar-application type herbicide, on a in situ Phaseolus vulgaris L. leaf was analysed with the chlorophyll fluorescence and thermal imaging system. The images of photosynthetic electron transport activity in photosystem II (Φ_PSII) and leaf temperature across a leaf surface were obtained before and after the herbicide treatment. At 30 min after the treatment, Φ_PSII began to decease in several sites within the treated region although the leaf temperature did not change. At 60 min after the treatment, the leaf temperature gradually increased at the sites whereΦ_PSII had markedly decreased. Those results showed that theΦ_PSII primarily decreased and the leaf temperature increased after the Basta treatment. This suggests that Basta initially inhibited the photosynthetic electron transport activity and the inhibition caused the stomatal closure. This study demonstrated that the early detection and detailed analysis of the physiological damage caused by herbicide are possible using the chlorophyll fluorescence and thermal imaging system.