Essential oil yields and qualities of different clonal lines of Salvia lavandulifolia monitored in Spain over four years of cultivation

Abstract

The current knowledge about the medicinal properties and marketing possibilities of the Spanish sage (Salvia lavandulifolia Vahl.) requires additional studies about the management of this valuable species. To this end, essential oil yields and chemistries from eleven different mother plants collected in the wild and cultivated in a single plot were obtained and monitored during four years (2010, 2011, 2013 and 2014) at three different phenological stages ((LF) leaves formation-vegetative, (FB) full bloom and (SM) seed maturation). Significant differences have been found in the yield over the phenology being the maximum essential oil production at the stage of SM. Besides, the yield enhanced by both the shortage periods of rainfalls and the plant age with in turn a maximum average yield recorded of 4.15% v/w in SM in 2014, at the end of the experiment. However, no distinction by clonal lines could be made regarding yield. Essential oil chemistry conversely, showed deeply influenced by the genotype from which the material for hydrodistillation was taken. Thus, the main essential oil compound recorded was the oxygenated terpene 1,8-cineole (36.7% in average value for whole experiment), with other accompanying important components such as α-pinene (7.8 %), β-pinene + myrcene (14.5%), limonene (6.2%) and camphor (7.1%). Besides, unlike the yield, essential oil chemistry was only partially influenced by the year of harvest with no relevant changes according to the phenological stage of the plant. Thus, phytochemical differences found in nature in the first place largely and even wider remain when plant growing under a common environment. Hence, some new and stable chemotypes were described according to their high values of α-pinene (>10%), limonene (>17%), 1,8-cineole (>50%), camphor (>20%) and β-caryophyllene (>7 %). This information is highly relevant for standardizing, assuring crop quality and for the proper management of the Spanish sage cultivation.