Then the parameters under
light (Fm and F0
) were measured under the quantum flux density of
2000 mmol m2 s1 in the steady state, i.e. about 5 min after onset
of the actinic light (400 mmol m2 s1). The variable fluorescence
(Fv) was calculated by the formula (Fm F0) and the maximum
photochemical efficiency of photosystem II (PSII) was calculated by
the ratio of Fv/Fm