Gas exchanges and growth of passion fruit seedlings under salt stress and hydrogen peroxide1

André Alisson Rodrigues Da Silva,Leandro De Pádua Souza,Carlos Alberto Vieira De Azevedo,Luana Lucas De Sá Almeida Veloso,Geovani Soares De Lima,Hans Raj Gheyi

doi:10.1590/1983-40632019v4955671

Abstract

ABSTRACT The semi-arid region of the Brazilian Northeast has adequate edaphoclimatic conditions for the passion fruit production, but the water used for irrigation commonly has high concentrations of salts that are harmful to the plant growth and development. A previous supply of hydrogen peroxide induces the acclimation of plants under saline stress conditions, reducing deleterious effects on their growth and physiology. This study aimed to evaluate the gas exchanges and growth of passion fruit as a function of irrigation with saline water and exogenous application of hydrogen peroxide. The experiment was carried out under greenhouse conditions, using a randomized block design, in a 4 x 4 factorial arrangement, being four levels of irrigation water electrical conductivity (0.7 dS m-1, 1.4 dS m-1, 2.1 dS m-1 and 2.8 dS m-1) and four hydrogen peroxide concentrations (0 µM, 25 µM, 50 µM and 75 µM), with four replicates and two plants per plot. The hydrogen peroxide application attenuated the deleterious effects of the irrigation water salinity on transpiration, CO2 assimilation rate, internal carbon concentration, plant height and leaf area of yellow passion fruit, at 60 days after sowing, with the concentration of 25 µM being the most efficient. Irrigation using water with electrical conductivity above 0.7 dS m-1 negatively affects the gas exchanges and growth of passion fruit, being the stomatal conductance and leaf area the most sensitive variables to the salt stress.

Highlights

Passion fruit (Passiflora edulis f. flavicarpa) is part of a group of fruit crops that has economic importance to Brazil, especially to the Northeast region, responsible for 60.92 % of the national production (IBGE 2017)
The passion fruit cultivation in the semi-arid region of the Brazilian Northeast can be optimized using techniques that allow the management of saline soil and/or saline water in agriculture
The exogenous application of hydrogen peroxide (H2O2) has shown to be promising in mitigating the effects caused by salt stress on crops (Carvalho et al 2011, Gondim et al 2011, Oliveira 2016)

Summary

Introduction

Passion fruit (Passiflora edulis f. flavicarpa) is part of a group of fruit crops that has economic importance to Brazil, especially to the Northeast region, responsible for 60.92 % of the national production (IBGE 2017). Flavicarpa) is part of a group of fruit crops that has economic importance to Brazil, especially to the Northeast region, responsible for 60.92 % of the national production (IBGE 2017). The passion fruit cultivation in the semi-arid region of the Brazilian Northeast can be optimized using techniques that allow the management of saline soil and/or saline water in agriculture. Among these alternatives, the exogenous application of hydrogen peroxide (H2O2) has shown to be promising in mitigating the effects caused by salt stress on crops (Carvalho et al 2011, Gondim et al 2011, Oliveira 2016)

Objectives

Methods

Results

Conclusion