Exogenous Application of Sodium Nitroprusside on the Morphophysiology of Passiflora edulis Sims Under Water Deficit

The availability of water is a limiting factor for the growth and productivity of yellow passion fruit (Passiflora edulis Sims). The use of bioregulators has been investigated as a strategy to mitigate the effects of abiotic stress. Different concentrations of SNP were evaluated on growth, gas exchange, photosynthetic pigments, chlorophyll fluorescence, and enzymatic activity in Passiflora edulis seedlings under different water conditions. The experiment was conducted in a randomized block design, in a 2 × 4 factorial scheme, with two irrigation conditions (80 and 30% of field capacity), combined with three concentrations of SNP (50, 100 and 250 µM) and water (control), with five replications. Water deficit reduced morphological, physiological, and enzymatic parameters. The application of SNP increased root fresh mass (23.56 g at the 100 µM dose) and leaf dry mass (8.21 g at 250 µM SNP), with increases of 24.52% and 30.52% compared to the values obtained under the 50 µM dose, respectively. The highest number of leaves (14) and leaf area (1183.3 cm2) was observed at 250 µM SNP, corresponding to increases of 7.70% and 17.27%, respectively, compared to plants without SNP application. Water deficit reduced growth, gas exchange, chlorophyll fluorescence, and enzymatic activity. SNP promotes improvements in growth; however, it does not mitigate water deficit effects in Passiflora edulis seedlings.