Chlorophyll fluorescence measurements
Chlorophyll (Chl) fluorescence was measured at different light regimes
to determine Fo, Fm,
Fm’, Ft, Fo’,
ΦPSII, qP and NPQ, according to (Maxwell
& Johnson, 2000), using a FMS-2 Pulse Modulated Fluorimeter (Hansatech
Instruments, Norfolk, UK). Plants were sequentially illuminated with
8000 μmol m-2 s1 saturating pulses
and 400 μmol m-2 s1 actinic light.