Similar Fv/Fovalues were observed for all genotypes under con-trol conditions (Fig. 5A and B). No changes were produced at T1 by3.5% PEG, except for the 8/cultivar plants (where Fv/Foincreasedwith respect to its control). However, at 7% PEG, Fv/Fofell in theungrafted plants (32% of control value) and, to a lesser extent inthe 5/cultivar and 8/cultivar plants (Fig. 5A).