Researching The Method Of Delayed Fluorescence Attributing Photosynthetic Capacity

Photosynthesis is the source of all vital movement of almost all living things in the global biosphere,it is the most important chemical reaction.Photosynthetic rate is the probe of revealing the operating and accommodating regulation of photosynthetic.Its determination is one of the most important methods of photosynthesis research.Delayed fluorescence(DF) phenomena can be described as light emission of photosynthetic organisms shortly after their illumination and only occurs in living cells.DF derives from the photosynthetic electron transport chain,light induced DF is slower than fluorescence,so it is more beneficial to research photosynthesis than chlorophyll fluorescence.The characteristics of DF itself determines its advantage in the detection of photosynthetic capacity:fast,accurate,lossless.This paper based on the emission and excitation characteristic of DF,and the dynamic decay regulation of DF,designs and implements a system of the dynamic decay signal detection of DF in vivo and environmental(the concentration of CO₂,temperature,humidity,excited light intensity,excited time) control,this system's core is the DF detector namely the module of passage type photomultiplier tube(CPDM), and the system merges the dark sample chamber and processing chassis;The DSP (TMS320F2812) is the processor for the system,it can process data rapidly,and improve the controllable degree of system;It integrates photoelectric sensor in the dark sample chamber;It also designs the regulation control module of the intensity of excitation light source.This system of the dynamic decay detection of DF is used to study DF attributing photosynthetic capacity of plants,and this experiment is research the relativity between DF intensity and net photosynthetic rate(Pn) in different excited light intensity in optimum conditions(temperature,humidity and the concentration of CO₂).When measuring,the photosynthetic rate tester(LI-6400) is used to measure the Pn of the leaves in the saturated light intensity firstly,using the DF detection system measures the DF intensity in different region of excited light intensity subsequently,and then the software of origin 7.5 is used to fit the data of measurement results,thereby obtaining the relativity between DF intensity and Pn.In the end,this paper makes a brief prospect on the application research of light induced DF,DF is taken as a extremely sensitive biological index,it can be widely applied in medical science,biology science and other fields.Finally,a full summary,of the thesis is given.