Effects of Lead Pollution on Photosynthetic Characteristics and Chlorophyll Fluorescence Parameters of Different Populations of Miscanthus floridulus

This study was conducted in order to the effect of different concentrations lead pollution on photosynthetic characteristics and growth Miscanthus floridulus, reveal its adaptability stress. The differences gas exchange parameters, chlorophyll fluorescence pigment two floridulus populations, one population from Boluo an uncontaminated site, another Dabaoshan, a mine were compared studied through nutrient solution culture experiments treated with heavy metal (Pb) green house. results showed that (1) under Pb stress, net rate (Pn), transpiration (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), content (Chl) leaves populations decreased amplitude. Under moderate severe stress (80 mg·L−1, 120 240 mg·L−1), plant biomass non-mining mining plants 54.5%, 39.7%, 29.4% 70.4%, 54.7%, 50.9% control, respectively. (2) Stomatal restriction main factor for Pn’s decrease non-mine light while non-stomatal middle high stresses. (3) maximum photochemical efficiency (Fv/Fm) potential activity (Fv/Fo) PS II reaction centers M. decreased. However, Fv/Fm Fv/Fo smaller decrease, but capability utilize activate PSII remained higher than population. changes quenching coefficient (qP) non-photochemical (NPQ) PSⅡ qP value NPQ increased On whole, resistance area had low reduction large increase NPQ. Electronic transfer (ETR) actual (ΦPSII) changed slightly These indicated when electron transport apparatus damaged less resistance. Conclusion: has strong tolerance Pb, which is suitable pioneer species gramineae vegetation restoration construction area.