Essential oils in pathogen resistance induction of Eucalyptus benthamii Maiden et Cambage/Oleos essenciais na inducao de resistencia a patogenos em Eucalyptus benthamii Maiden et Cambage

• Published in: Ciência rural 2021-09, Vol.51 (9), p.1
• Main Authors: Stenger, Luma Dalmolin, Libardoni, Gabriela, Wagner, Américo, Júnior, Zanela, Juliano, Alves, Leonardo Tozzetti, Varpechoski, Gabriela Osowski, Lozano, Everton Ricardi, Potrich, Michele
• Format: Article
• Language: English
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20190915

This study evaluated the essential oils ofMelaleuca alternifolia, Casearia sylvestris and Eugenia uniflora as inducers of defense mechanisms in Eucalyptus benthamii seedlings. Four mL of each oil, with a concentration of 0.75% were sprayed in E. benthamii seedlings and two bioassays were performed, in the first, the essential oils were sprayed and after 30 days, sugars, proteins, peroxidases, phenylalanine ammonia (PAL), and phenols were evaluated and; in the second, seven days after the first analysis, the essential oils were again sprayed and after three days, the same variables were evaluated. The essential oils of M. alternifolia, C. sylvestris, and E. uniflora sprayed had no significant effects on E. benthamii seedlings after 30 days in terms of total sugars, proteins, peroxidase, PAL activity, and phenols. However, when M. alternifolia and E. uniflora essential oils were sprayed seven days after the first analysis with evaluation after 3 days, an increase in total sugars was observed. After these days, all essential oils promoted an increase in protein levels. The oils of E. uniflora and C. sylvestris also increased peroxidase levels. The PAL defense enzyme not showed increased when essential oils were used. The essential oils of M. alternifolia and C. sylvestris had potential as inducers of defense mechanisms on E. benthamii seedlings after 3 days of their application, what it demonstrated not be permanent. Key words: biotic inductors, Melaleuca alternifolia, Casearia sylvestris, Eugenia uniflora. Este trabalho teve como objetivo avaliar os óleos essenciais de Melaleuca alternifolia, Casearia sylvestris e Eugenia uniflora como indutores de mecanismos de defesa em mudas de Eucalyptus benthamii. Quatro mL de cada óleo, com concentração de 0,75%, foram pulverizados em mudas de E. benthamii e foram realizados dois bioensaios. No primeiro foram pulverizados os óleos essenciais e após 30 dias, açúcares, proteínas, peroxidases, fenilalanina amónia (PAL), e fenóis foram avaliados e; na segunda, sete dias após a primeira análise, os óleos essenciais foram novamente pulverizados e após três dias, as mesmas variáveis foram avaliadas. Os óleos essenciais deM. alternifolia, C. sylvestris e E. uniflora pulverizados não tiveram efeito significativo sobre as mudas de E. benthamii após 30 dias em termos de açúcares totais, proteínas, peroxidase, atividade PAL e fenóis. Entretanto, quando os óleos essenciais deM. alternifolia e E. uniflora foram pulverizados sete dia