Detection of Stress Physiology of Plant Using F730/F685 Ratio of Delayed Fluorescence Spectrum

Delayed fluorescece(DF) is intrinsically related to the photosynthesis process,and it is a good method of researching the effect of various chemical and physical factors in vivo and in vitro on photosynthetic performance of plants.In this paper,the detection of DF emission spectra under the stress(heat,salt and UV-B) have been investigated in maize(98-2) sample.The maximal values of DF emission spectra at 685 nm and 730 nm were marked as F685 and F730 respectively.After comparative measurement of F730/F685 ratio,DF intensity and Fv/Fm,the linear fitting results shown that the two parameters has a good linear correlation(R2≥0.960 9).The experimental results suggest that the degree of plant photosynthetic physiology damage whether caused by different concentration or different stress time can be effectively measured by F730/F685.Moreover,the responses of F730/F685 ratio of DF emission spectra to the stress could be a new and useful judgment to identify and evaluate the stress damage of the samples.