Volatile essential oil chemical composition of basil (Ocimum basilicum L. ‘Green’) cultivated in a greenhouse and micropropagated on a culture medium containing copper sulfate

Abstract

The objective of this study was to determine the effects of copper sulfate (CuSO4) on the chemical composition of basil (Ocimum basilicum L. ‘Green’) using static headspace extraction. The basil was cultivated in vitro and ex vitro. The sowing was completed in trays, and the seedlings were transplanted to pots and grown in a protected environment for 180 d. For in vitro cultivation, the seeds were placed on Murashige and Skoog (MS) medium enriched with growth regulators, sucrose, agar, and CuSO4 (at 0 μM [control], 25 μM, or 75 μM). Volatile organic compounds emitted from the excised leaves were collected by the static headspace technique, and identified by gas chromatography coupled to mass spectrometry (GC/MS). Twenty-six compounds were identified in the leaves harvested from the plants cultivated in vitro, while 11 compounds were identified in the leaves sampled from the ex vitro plants. Oxygenated monoterpenes were the main compounds found in plants cultivated ex vitro. Phenylpropanoids predominated in the control and the 25 μM CuSO4 treatments. The main compounds found were methyl eugenol (52.03%) and eugenol (20.66%). For the 75 μM CuSO4 treatment, the major compounds detected were linalool (28.14%) and 1.8-cineole (15.7%). Volatile secondary metabolites of basil cultivated in vitro with CuSO4 were easily isolated and rapidly obtained. The results of this study demonstrate the feasibility and potential of using copper treatments to reduce the impact of seasonality on essential oil production.