Variability of Essential Oil Content and Composition of Origanum vulgare L. Populations from a North Mediterranean Area (Liguria Region, Northern Italy)

Native populations of Origanum vulgare L. from the Liguria andEmilia regions of northern Italy were analysed for essentialoil content and composition. Morphological characters suggestedthat the Ligurian samples belonged to the ssp. viride. The essentialoil content of inflorescences ranged from less than 5 mg g^-1inthe samples from Emilia, to more than 50 mg g^-1in some Liguriansamples, values similar to those reported for ssp. hirtum fromsouthern Italy. Sixty-four compounds were identified in theessential oil. The samples were allotted to three main groupson the basis of oil composition: the first group had a highcontent of components belonging to the carvacrol/thymol biosyntheticpathway; the second was characterized by a different sesquiterpenecomposition and a high linalool content; and the third, includingthe two samples of ssp. vulgare from Emilia, was characterizedby the presence of abundant sesquiterpenes. The high essentialoil content of the samples studied, and the presence of someparticular morphological characters suggest that the taxonomyof O. vulgare, especially in its western distribution area,needs further investigation. Linalool types, although oftennot considered as ‘typical oregano’, may be usefulin promoting wider utilization of the biodiversity of this species.Copyright 2000 Annals of Botany Company Oregano, Origanum vulgare L., ssp. viride, ssp. vulgare, ssp. hirtum, essential oil, gas chromatography, mass spectrometry, genetic resources, chemotypes, quality, Mediterranean