A similar behavior was detected for the leaf greenness index.
Drought-induced decline in A appeared as mostly due to decrease
in stomatal conductance (data not shown, but see E in Table 1) and
not a consequence of impairment in PSII photochemistry, as Fv/Fm
did not differ between WW and WS plants throughout the
experiment.
Jw progressively became more negative during drought (NIV
for Jw were þ3%, þ11% and þ26% on 0 DAT, 8 DAT and 18 DAT,
respectively) but, even when available water in the substrate was
very low, never fell below 1 MPa (Table 1). The drought-induced
change in Jw was mainly due to changes in Jp, as water stress did
not induce any appreciable change in Jp (NIV¼1% and 68% for
Jp and Jp, respectively). Jw and Jp of drought-stressed plants
equaled those of controls by the end of the relief period.