A VIRUS DISEASE AFFECTING SALVIA OFFICINALIS L. ´MAXIFOLIA´ AND ITS EFFECTS ON ESSENTIAL OIL PRODUCTION AND COMPOSITION

In 2004, Salvia officinalis L. “Maxifolia” (“sage”; Lamiaceae family), grown at the Herb Garden of Casola Valsenio (Ravenna, northern Italy), was found to be infected by a rod-shaped virus probably belonging to the Tobamovirus genus. Characteristic symptoms on almost 60-70% of plants were chlorotic mosaic and/or yellow rings on the leaves and stunting. The virus was mechanically transmitted to herbaceous species belonging to Chenopodicaeae, Compositae, Cucurbitaceae and Solanaceae families. In leaf-dip preparations elongated rod-shaped particles (of about 300 nm in length) were observed; examination of ultrathin sections of small symptomatic leaf fragments of S. officinalis revealed the presence of amounts of virus particles, associated with chromosomes, scattered in the cytoplasm. The essential oil from both healthy and virus-infected sage plants was evaluated by means of GC-MS with the aim of identifying differences due to the diseases. The oil yields were 4mL/kg and 4,5 mL/kg for healthy and infected sage respectively. The composition of the essential oil from infected S. officinalis “Maxifolia” plants did not show significant differences when compared with healthy samples. Only a slight increase in sesquiterpenes and a decrement in aliphatic monoterpene content was noticed. Up to now no elongated virus had been found naturally infecting sage. From these studies, it is evident that composition of oils from sage is highly dependent not only on genotype, vegetative stage, agronomic factors and environmental conditions of the crops, but also to the phytopathological status of essential oil bearing plants.