In situ monitoring system for chlorophyll fluorescence parameters of tomato at greenhouse in northern China.

摘要

Light pattern plays a crucial role in crop photosynthesis in different growth stages, and the photosynthesis process can be reflected by the chlorophyll fluorescence parameters. The chlorophyll fluorescence monitoring system in this study is composed of a PC (host computer), a programmable constant current power supply and a MINI-PAM, which is a modulation fluorescence detector. The chlorophyll fluorescence parameters of tomato, such as Fs (Steady-state fluorescence), F'm (Maximal fluorescence) in illuminated samples, ETR (Electron Transport Rate), PAR (Photosynthetically Active Radiation) and Phi PS_II (Quantum yield of PSII during exposure to light) were measured, then the light use efficiency was analyzed according to the measured light response curve of tomato in a fixed growth cycle, and the influence of light intensity on the tomato growth mechanism was determined further. According to the relation model between light intensity and fluorescence parameters, the information of host computer was set to monitor the quantitative fluorescence parameters, so the light control environment was established to guide the dynamic output. The 'Liaoyuanduoli' tomato grown in greenhouse of north China was studied in this experiment. The results show that the change of fluorescent parameters depends on the change of the PAR closely. The increase of PAR makes Fs higher significantly while F'm lower correspondingly, thus the quantum yield of Phi PS_II was decreased. Therefore, the system can achieve monitoring in the quantitative fluorescent parameters, so as to realize the actual measurement and quantitative control of plant photosynthetic capacity.