Hydrogen peroxide in the acclimation of yellow passion fruit seedlings to salt stress/Peroxido de hidrogenio na aclimatacao de mudas de maracujazeiro amarelo ao estresse salino

• Published in: Revista brasileira de engenharia agrícola e ambiental Vol. 25; no. 2; p. 116
• Main Authors: Silva, Andre A.R. da, Veloso, Luana L.S.A, Lima, Geovani S. de, Azevedo, Carlos A.V. de, Gheyi, Hans R, Fernandes, Pedro D
• Format: Journal Article
• Language: English
• Published: ATECEL--Associacao Tecnico Cientifica Ernesto Luiz de Oliveira Junior 01.02.2021
• Subjects: Brasil
• ISSN: 1415-4366; 1807-1929
• DOI: 10.1590/1807-1929/agriambi.v25n2pll6-123

HIGHLIGHTS: Hydrogen peroxide mitigates the effects of water salinity on the gas exchange of yellow passion fruit. Saline stress inhibits the emergence and relative growth in height of passion fruit plants. High concentration of hydrogen peroxide intensifies the effect of salt stress on passion fruit. The objective of the present study was to evaluate the effect of exogenous application of hydrogen peroxide on the emergence, growth and gas exchange of yellow passion fruit seedlings subjected to salt stress. The experiment was conducted in pots (Citropote[R]) under greenhouse conditions, in the municipality of Campina Grande, PB, Brazil. Treatments were distributed in a randomized block design, in a 4 x 4 factorial arrangement, with four levels of electrical conductivity of irrigation water (0.7, 1.4, 2.1 and 2.8 dS [m.sup.-1]) associated with four concentrations of hydrogen peroxide (0, 25, 50 and 75 [micro]M), with four replicates and two plants per plot. Irrigation using water with electrical conductivity above 0.7 dS [m.sup.-1] negatively affects the emergence and growth of passion fruit. Hydrogen peroxide concentrations between 10 and 30 [micro]M induce the acclimation of passion fruit plants to salt stress, mitigating the deleterious effects of salinity on the relative growth rate in stem diameter and leaf area, stomatal conductance, transpiration, [CO.sub.2] assimilation rate and instantaneous carboxylation efficiency. Irrigation water salinity combined with hydrogen peroxide concentrations above 30 (iM causes reduction in passion fruit growth and physiology. Key words: Passiflora edulis Sims f. flavicarpa Degener, saline waters, mitigation Objetivou-se com o presente trabalho, avaliar o efeito da aplicacao exogena de peroxido de hidrogenio sobre a emergencia, o crescimento e as trocas gasosas de mudas de maracujazeiro amarelo submetido ao estresse salino. O estudo foi conduzido em citropotes sob condicao de casa de vegetacao, no municipio de Campina Grande, PB. Os tratamentos foram distribuidos em delineamento de blocos casualizados, em arranjo fatorial 4x4, sendo quatro valores de condutividade eletrica da agua de irrigacao (0,7; 1,4; 2,1 e 2,8 dS [m.sup.-1]) associados a quatro concentracoes de peroxido de hidrogenio (0, 25, 50 e 75 yM), com quatro repeticoes e duas plantas por parcela. A irrigacao com agua acima de 0,7 dS [m.sup.-1] afeta negativamente a emergencia e o crescimento do maracujazeiro. Concentracoes de peroxido de hidrogenio entre 10 e 30 [micro]M induz a aclimatacao das plantas ao estresse salino, mitigando os efeitos deleterios da salinidade sobre a taxa de crescimento relativo em diametro de caule e area foliar, condutancia estomatica, transpiracao, taxa de assimilacao de [CO.sub.2] e eficiencia instantanea da carboxilacao. A salinidade da agua de irrigacao aliada a concentracoes de peroxido de hidrogenio acima de 30 yM causa reducao no crescimento e na fisiologia do maracujazeiro amarelo. Palavras-chave: Passiflora edulis Sims f. flavicarpa Degener, aguas salinas, mitigacao