植株叶绿素a和叶绿素b无损检测系统研究与开发

针对透射式叶绿素检测技术在检测较高含量叶绿素叶片时的局限性,研究设计基于光学漫反射式新颖的叶绿素检测系统,实现无损在线测试,直接输出植株叶片叶绿素a和b值。该检测系统采用3光源3光束垂直入射密闭光路设计,选用645 nm和663 nm 2个特征波长作为叶绿素a和b的检测波长,800 nm作为参照波长;采用光源调制、高通滤波放大和软件算法等消除外界光干扰;以透光度75%的消光片对该检测系统进行稳定性和重复性测试评价。测评结果为稳定性RSD≤0.39%(n=20),重复性RSD≤0.59%(n=20)。选取小麦、玉米、花卉共344个样本,漫反射法和常规Arnon法的叶绿素a和b总量的相关性达到极显著水平;且适用于厚度约3.0 mm玻璃翠花叶片的检测。

Plant Chlorophyll a and Chlorophyll b Nondestructive Testing System: Research and Development

Aiming at the limitations of the transmission spectra for the detection of chlorophyll content at a high concentration, a novel optical detection system using the theory of diffuse reflection was developed. The detection system could show the concentration of chlorophyll a and b in plant leaves in real-time by nondestructive diagnostic technique. In this detection system, the light system was in an enclosed dark room, which adopted the design method of three light sources and three beams incident vertically, the characteristic wavelength of 645 nm and 663 nm were selected as the detection wavelength of Chlorophyll a and b, and the wavelength of 800 nm was the reference wavelength. The light source modulation, high-pass filter amplification and mathematical algorithm were used to eliminate the interference from the external light-source. The stability and repeatability of the detection system were carefully evaluated with a 75% permeable extinction film. The stability with relative standard deviation (RSD) ≤0.39% (n=20) and the repeatability with RSD≤0.59% (n=20) were obtained from this detection system. A total of 344 samples of wheat, corn, and flowers were selected, the correlation of chlorophyll a and b total correlations r between the diffuse reflectance and the conventional Arnon reached a very significant level. The diffuse reflectance could be used to detect glass emerald leaf with the thickness of about 3.0 mm.