The plant net photosynthetic rate(Pn)measurement using saturated light-induced delayed fluorescence(DF) has some disadvantages,such as large power consumption,short sustainable working hours,etc.In this paper,the leaves of rice (Jin You No.207) were taken as samples to illustrate the relationships between the decay curves and intensities of different unsaturated and saturated light-induced DF.DF intensity and Pn were measured by a home-made portable DF detection device and LI-6400,respectively,and the compa...