HIGHLIGHTS:
Hydrogen peroxide favors the physiology and growth of passion fruit seedlings.
Hydrogen peroxide application allows the use of brackish water in the production of passion fruit seedlings.
Methods of application of H2O2 have a distinct influence on the physiology and growth of passion fruit seedlings.
ABSTRACT
Hydrogen peroxide (H2O2) can be indicated as a strategy to mitigate salt stress in plants, so the objective of this study was to evaluate the effect of different concentrations and methods of application of H2O2 as a mitigator of salt stress on the growth, physiology, and quality of seedlings of yellow passion fruit. The experiment was carried out in a protected environment (screened) belonging to UFERSA, in Caraúbas - RN, Brazil, in a randomized block design and analyzed in a 2 × 4 × 3 factorial scheme, with four replications and one plant per plot. The treatments consisted of levels of electrical conductivity of irrigation water - ECw (0.5 and 3.2 dS m-1), H2O2 concentrations (0, 12, 24, and 36 μM), and H2O2 application methods (M1 = seed soaking, M2 = foliar spraying, and M3 = seed soaking + foliar spraying). Increased levels of salinity in irrigation water negatively affect seedling quality. Hydrogen peroxide at an average concentration of 24 µM mitigates salt stress in passion fruit seedlings cv. BRS Gigante Amarelo. H2O2 application to seeds associated with foliar spraying mitigates the effects of salt stress on the absolute growth rate of the leaf area of passion fruit seedlings irrigated with an ECw of 3.2 dS m-1.
Key words:
Passiflora edulis Sims; irrigation; salinization; hydrogen peroxide
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Vertical bars represent the standard error of the mean (n=4). Means followed by different letters indicate a significant difference between treatments by the Tukey test at p≤ 0.05
M1 - Seed imbibition; M2 - Foliar spraying; M3 - Seed imbibition + foliar spraying. For the SL x H2O2 interaction, means followed by different letters indicate a significant difference between treatments by Tukey test at p≤0.05, lowercase letters indicate the behavior of salinity levels within each H2O2 concentration and uppercase letters indicates the behavior of doses of H2O2 at the same water salinity level. For the M × H2O2 interaction, uppercase letters indicate the behavior of the methods of application within doses of H2O2. Vertical bars represent the standard error of the mean (n=4)
Vertical bars represent the standard error of the mean (n=4). Means followed by different letters indicate a significant difference between treatments by the Tukey test at p ≤ 0.05 probability
M1 - Seed imbibition; M2 - Foliar spraying; M3 - Seed imbibition + foliar spraying. For the SL x M interaction, means followed by different letters indicate a significant difference between treatments by the Tukey test at p≤0.05, uppercase letters indicate the behavior of the methods of application within the salinity levels and lowercase letters indicate the behavior of each salinity level within the methods of application. Vertical bars represent the standard error of the mean (n=4)
M1 - Seed imbibition; M2 - Foliar spraying; M3 - Seed imbibition + foliar spraying. Means followed by different letters indicate a significant difference between treatments by the Tukey test at p ≤ 0.05, lowercase letters indicate the behavior of each salinity level within the method of application and uppercase letters indicate the behavior of methods of application at the same salinity level. Vertical bars represent the standard error of the mean (n=4)
For the SL x H2O2 interaction, means followed by different letters indicate a significant difference between treatments by the Tukey test at p≤0.05, lowercase letters indicate the behavior of salinity levels within each H2O2 concentration and uppercase letters indicate the behavior of H2O2 levels at the same salinity level. Vertical bars represent the standard error of the mean (n=4)