Fig. 2

Minimal fluorescence yield of the dark-adapted state (F₀), maximal fluorescence yield of the dark-adapted state (F_m), variable fluorescence (F_v) and maximal quantum yield of PSII photochemistry (F_v/F_m) in young Eucalyptus urophylla plants sprayed with EBR and exposed to Ni toxicity. Columns with different letters indicate significant differences from the Scott-Knott test (P < 0.05). Columns corresponding to means from five repetitions and standard deviations