Composition and antifungal activity of the essential oils hydrodistilled from three accessions of pastinocello carrot (Daucus carota L. ssp. major)

Abstract

In line with the actual increasing request of innovative and alternative tools aimed to reduce the use of chemicals in favor of more sustainable agriculture and food systems, natural products, such as essential oils (EOs), represent a valid alternative to pesticides. Essential oils contain antioxidant and antimicrobial constituents able to act against plant pathogens, including phytopathogenic fungi. Despite species belonging to Daucus genus are already known as a source of active essential oils, little is known about D. carota ssp. major (pastinocello), a local carrot variety, now listed among the species facing extinction risk. With the aim to investigate this species, the present work aimed to study three pastinocello accessions cultivated in Central Italy, in terms of bio-agronomic characteristics, inflorescence production, essential oils yield and composition, and their activity against plant pathogenic and beneficial fungi. Results showed significant morphological and productive differences among accessions as well as a significant different composition in their essential oils, with accession L24 richer in oxygenated sesquiterpenes class (such as carotol and daucol) and L281 and L305 showing monoterpene hydrocarbons as the most abundant chemical groups. At the same time the EO obtained from L24 was the most effective in reducing the growth of two important plant pathogenic fungi, Fusarium oxysporum f. sp. lycopersici and Monilinia fructigena, while any effect was observed against two well-known beneficial isolates belonging to Trichoderma genus.These results not only confirm the possibility to use EOs from pastinocello to control plant pathogenic fungi, but also leave open the possibility of a combined use with beneficial Trichoderma isolates, already exploited as biocontrol agents for the management of plant diseases.