Objective: To study the impacts of lead (Pb) stress on the leaf photosynthetic pigment and the growth of Rabdosia rubescens,in order to provide a basis for planting area selection and growth regulation.
Methods: Taking chlorophyll a, chlorophyll b, carotenoids, growth rate, biomass and Pb content as the indexes, the Ramets hydroponic experiments at Pb concentration levels (135,270 and 540 mg/L) in the time(20, 35 and 50 d) were carried out. Photosynthetic pigment content was determined by spectrophotometer, and Pb mass fraction was detected with plasma emission spectrometer.
Results: There was uncertain effect on chlorophyll and carotenoid synthesis in different Pb concentrations in-early period (20 and 35 d). At the time of 50 d, the chlorophyll content was higher in the low-mid Pb concentrations, significantly lower in the high Pb concentration compared with the control group, and there were no significant differences on carotenoid contents in different Pb concentrations.
Conclusion: Low-mid Pb concentrations can promote chlorophyll synthesis, and the bioaccumulation of high Pb concentration can inhibit the chlorophyll synthesis, and then restrict the growth of Rabdosia rubescens.