Cultivo in vitro de Campomanesia rufa [O. Berg] Nied.extração de óleo essencial em folhas: abordagem fitoquímica, fisiológica, anatômica,bioquímica e antibacteriana

Abstract

Campomanesia rufa [O.Berg.] Nied (C. rufa). is a woody and fruitful species popularly known as gabiroba. Studies on phytochemistry and in vitro culture on these species are incipient. The aim of this work at first was to characterize the essential oils (EsO) of the leaves and to verify its antibacterial potential, besides analyzing the presence of secretory cavities (SC) with volatile compounds. Subsequently, the objective was to analyze the biometric, biochemical, and anatomical aspects of the species in vitro cultivation under different light spectra and plant growth regulators. The extraction of EsO from the leaves of C.rufa was performed using the hydrodistillation technique, using a modified Clevenger apparatus. Histochemical and anatomical tests were performed on the leaves for structural analysis of the epidermis cells, parenchymal tissues, vascular bundle, and secretory cavities, in addition to phytochemistry for the analysis of lipids and terpenes. For the tests of antibacterial activity, the technique of minimum inhibitory concentration of EsO on Staphylococcus aureus and Escherichia coli was performed. In in vitro cultivation, the plants were subjected to seven light spectra, which were provided by light emitting diodes and fluorescent lamps. Subsequently, the anatomy of the leaves and analysis of photosynthetic pigments were performed. In another step, a fixed dose of benzylaminopurine (BAP) was applied to the culture medium and after inoculation of the explants, they were kept in the absence of light and in the presence of purple LED or fluorescent lamp. Another experiment carried out was with polyamine, in which different concentrations of spermine were applied to the culture medium. In vitro multiplication of explants was also carried out through the combination of two types of cytokinins, in addition to the induction of roots using different concentrations of IBA. The major compounds found in the EsO were (2E, 6E)- farnesal (41.64%), (2E,6Z)-farnesal (27.74%), (2E, 6Z)-farnesol (3.54%). Volatile compounds were found in SC. Bacterial growth was inhibited by diluting 7.10 μL mL -1 of EsO. Light quality influenced biometric, biochemical, and anatomical analyses. In the presence of BAP and purple LED observed higher biometric values. The combination of two cytokinins, 2 mg L -1 of 2-ip and 1 mg L -1 of BAP provided a high number of shoots at 40 days (5.80). At rooting, 37.5% of the plants rooted at a concentration of 4 mg L -1 of IBA. Therefore, it is concluded that the leaves of C. rufa have essential oil with antibacterial activity. Purple LED is efficient in inducing C. rufa sprouts in vitro, as well as BAP combined with 2-ip. Spermine promotes the development of plants in vitro. AIB induces rhizogenesis.