Preliminary results on basil grown in the Nemo's Garden®

Nemo's Garden is a prototype to create an alternative system of agriculture, especially dedicated to those areas where environmental conditions, economical or morphologic reasons make plants growth extremely difficult. Technology developed in the framework of Nemo's Garden Project might help create efficient plant production in an alternative and economical way in respect to standard greenhouses, looking at new branches of green and blue economy. In 2015 several plant species were cultivated in the Nemo's Garden, located on the seabed near Noli (Liguria, Italy). Basil (Ocimum basilicum L.) was chosen as model plant to study its botanical, physiological and phytochemical characteristics in comparison with the same plants grown in greenhouse or in open field.

Phytochemical evaluation of the spontaneous volatile emission and of the essential oil of the living specimens were analysed by GC-MS. Sesquiterpene hydrocarbons were the most abundant chemical class of VOCs in the HS (61.2%) with trans-α-bergamotene as the major compound (26.0%). The identified chemotype of the EO was methyl eugenol (49.6%). The botanical survey was performed by means of both light and electron microscopy in order to investigate the distribution, morphology, structure and histochemistry of the glandular trichomes responsible for the production of volatiles. Particular attention was paid to ultrastructure, aiming at characterize the cellular compartments involved in the secretory process. We determined the photosynthetic pigments in mg/g FW: chlorophyll a and b (2.378 and 2.156, respectively), carotenoids (267.614) and the ratio CHLa/CHLb (1.103) were determined in young leaves. Total polyphenols (4.25 ± 0.15 mg/g DW) and the relative antioxidant activity (IC₅₀ DPPH, 0.165 mg DW/ml) were also investigated.

Keywords: HS-SPME, essential oil, glandular trichome, photosynthetic pigments, antioxidant activity.

No conflict of interest has been declared by the author(s).