Photosynthetic activity and chlorophyll content of broad bean leaves after treatment with different concentrations of Chlorella suspension raging from 0 to 1.0×10¹⁰ ind mL⁻¹ for 48 h.

Fv/Fm, maximum quantum yield of photosystem II (PSII); ΦPSII, effective quantum yield of PSII; NPQ, non-photochemical quenching; qP, photochemical quenching; ETR, electron transportation rate; Chl. a, Chl. b, Chl. a + b, chlorophyll a, chlorophyll b, total chlorophyll content, expressed as mg per g fresh weight; Chl. a/b, ratio of chlorophyll a to b. Each value represents the mean ± SE (n = 14). Means estimates with same letters are not significantly different among treatments as determined by ANOVA (LSD test, P<0.05).