Some morphological and chemical characteristics of oregano (Origanum vulgare L.) in Latvia
¹Latvia University of Life Sciences and Technologies, Liela iela 2, LV-3001 Jelgava, Latvia
²Warsaw University of Life Sciences, Nowoursynowska 159, PL02-776 Warsaw, Poland
By European Cooperative Programme for Plant Genetic Resources (ECPGR), oregano (Origanum vulgare L.) is included on the list of priority species of medicinal and aromatic plants. In Latvia, it is important to cultivate oregano for keeping biodiversity and for meeting the needs of medicinal plant`s production. 44 accessions of oregano from the ex situ collection of genetic resources of medicinal and aromatic plants, attached to the Latvia University of Life Sciences and Technologies, were analysed during 2012–2014. Plants` morphological characteristics were described by the Draft Descriptor List of oregano, using the methodology of ECPGR. The essential oil was isolated using solvent-free microwave extraction method and analysed by gas chromatograph Hewlett Packard 6890 equipped with flame ionization detector FID and polar capillary column HP 20M. The results showed, that oregano accessions differ morphologically. Accessions are characterized with dense branching and the possibility to create big biomass. Local oregano is poor in content of essential oil, but 17 compounds were identified as the principal. As well as the correlation between the content of essential oil and colour of flowers in full flowering stage was observed – it is higher for accessions with dark flowers. Also, the influence of meteorological conditions per vegetation period (year) on chemical characteristics was significant (p < 0.05).