基于光脉冲诱导快相与弛豫荧光的光合作用参数测量技术

为了更准确获取反映植物生理状态的荧光动力学曲线,基于光合作用电子传递过程研究了植物光合作用参数测量技术.采用可变光脉冲技术将植物光合作用过程分段为快相与弛豫过程,并测量激发光诱导产生的荧光动力学曲线.对激发光带宽与响应时间进行了定量分析;对I-V转换单元与MFB滤波器进行了设计与仿真分析,获取快相荧光动力学信息;采用同步脉冲采样积分技术,对微弱弛豫荧光进行积分,实现了快相与弛豫荧光动力学曲线的完整测量,并结合非线性拟合算法获取光合作用参数.测试结果表明,系统信噪比达到23.8 dB;暗适应与光适应下,本系统所测Fv/Fm与Water-PAM测量结果的线性相关系数分别达到0.980和0.997.该研究结果为植物光合作用研究及过程参数测量提供了一种测量手段.

Photosynthesis Parameters Measurement Technology Based on Fast Phase and Relaxation Fluorescence Induced by Optical Pulses

The photosynthetic parameters can reflect the physiological state of plants.In order to obtain a more accurate fluorescence kinetic curve,a technique for measuring plant photosynthetic parameters based on the electron transfer process was proposed in this paper.Variable excitation light pulses was employed to devide the plant photosynthesis process into two stages:fast phase and relaxation phase,and corresponding fluorescence curves were induced for each stage.The excitation bandwidth and response time were analyzed using the TINA simulation tool.The I-V conversion and MFB filter were designed and simulated quantitatively.Synchronous sampling integral technique was employed to improve the SNR of weak relaxation phase fluorescence.As a result,a complete fluorescence kinetics curve that consist of fast phase and relaxation phase was obtained,from which the plant photosynthesis parameters can be calculated using nonlinear fitting algorithm.Experiment results showed that the system SNR reached 23.8 dB,and the correlation coefficients of measured Fv/Fm that obtained by this system were respectively 0.980 and 0.997 for dark and light adaptation conditions.