MELALEUCA ALTERNIFOLIA ESSENTIAL OIL AND 4-TERPINEOL AS POTENTIAL ANTIMICROBIAL IN THE IN VITRO CULTIVATION OF PLANTS

• Grant number: 24/13025-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2024
• Effective date (End): May 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Jean Carlos Cardoso
• Grantee: Mariana Vignola
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

In vitro plant cultivation is used to quickly produce clonal seedlings of superior genotypes. However, the high contamination of culture media by microorganisms limits the technique, causing plant losses and increasing production costs. The great antimicrobial potential of essential oils and their terpenes is of great interest to the scientific community, especially for plant cultivation. Melaleuca alternifolia oil (OE) stands out for its antifungal and antibacterial properties, due to its high concentration of the monoterpene 4-terpineol (4T). Therefore, the objectives of the work will be to evaluate the efficiency of OE and 4T in controlling microbiological contamination of culture media, as well as evaluating the phytotoxicity of both. To achieve this, two experiments will be conducted with different concentrations (0%; 0.2%; 0.4%; 0.6% and 0.8%) of EO and 4T. In the first experiment, the treatments will be added and autoclaved, in the second they will be added cold, after autoclaving. Then, the culture media will be purposefully exposed to airborne microorganisms present in the growth room and maintained in a germination chamber at 28°C, for periodic assessments of the number, type and diameter of colonies, in addition to Gram staining (bacteria). and morphological evaluation of hyphae (fungi). The phytotoxic potential will be tested using apical segments of shoots of Mandevila sp. and Dendrobium explants (var. 2023). These will be subcultured into test tubes containing the treatments, at concentrations that show inhibitory efficiency and signs of senescence will be observed in the plant materials. The knowledge generated by this work will serve as a basis for the development of commercial products that aim to reduce contamination in plant micropropagation.