Chlorophyll Fluorescence in Leaves of Ficus tikoua Under Arsenic Stress

A greenhouse culture experiment was used to quantify effects of arsenic (As) stress on the growth and photochemical efficiency of Ficus tikoua (F. tikoua). Results showed growth of F. tikoua leaves was significantly inhibited at As concentrations higher than 80 mu mol/L in solution. Root arsenic concentration was significantly higher than that in stem and leaf. The 320 and 480 mu mol/L As concentrations in solution resulted in significant decreases in maximum quantum efficiency of photosystem II (PSII) (Fv/Fm), variable to initial chlorophyll fluorescence (Fv/Fo), and quantum yield of PSII electron transport (Y(II)) of F. tikoua leaves, whereas significantly higher non-photochemical quenching of fluorescence and photochemical quenching of fluorescence values were found at 160, 320 and 480 mu mol/L As concentrations in solution, implying that PSII reaction centers were damaged at high As concentrations and that F. tikoua eliminates excess energy stress on the photochemical apparatus to adapt to As stress.