Monteiro, Ana Maria da SilvaFigueiredo, Ana CristinaBerg, Cássio Van denRodrigues, Leandra Sofia de Matos2014-01-232014-01-232012Rodrigues, L.S.M. -Phytochemical and genetic diversity in Mentha species: assessment, valorization and conservation. Lisboa: ISA, 2012, 211 p.http://hdl.handle.net/10400.5/6390Doutoramento em Engenharia Agronómica - Instituto Superior de AgronomiaMentha cervina (L.) Opiz and Mentha pulegium L. are medicinal and aromatic plants traditionally used in Portugal for aromatic and seasoning purposes and in folk medicine, for treatment of gastric and respiratory problems. Light and scanning electron microscopy of both species indumentum revealed non-glandular and glandular trichomes, corresponding to the common arrangement in Lamiaceae. Gas Chromatography and Gas Chromatography–Mass Spectrometry of both species essential oils (EOs) showed no chemical polymorphism in populations with different provenances, in cultivated or in wild growing conditions and at different developmental stages. All populations EOs belonged to the pulegone chemotype. M. cervina EOs antibacterial activity was higher than the main components alone, supporting the hypothesis of a synergistic effect of their different components. The antibacterial activity was more effective against Escherichia coli and Acinetobacter baumanni, validating their traditional use. The low levels of genetic diversity and the high structuring of M. cervina populations, assessed with Inter-simple sequence repeats markers, were assumed to result from a combination of evolutionary history and its unique biological traits, such as breeding system, clonal growth, low dispersion capacity and habitat fragmentation. The results point the necessity of conserving the maximum possible number of populations and sites for ex situ conservation.engMentha cervinaMentha pulegiumtrichomesessential oilsGC-MSpulegonegenetic diversityISSRsbioactivitygenetic conservationdoctoral thesis