Variability of essential oil in cultivated populations of Rosmarinus officinalis L. in Spain

Rosmarinus officinalis L. (synonym Salvia rosmarinus Schleid) grows in the Mediterranean basin and is known to be a source of natural bioactive compounds and one of the most important aromatic species in terms of the marketing of the essential oil. However, wild collection and the lack of selection lead to the absence of standardized material that ensures the homogeneity and quality of the essential oils over time. In the present work, thirteen wild Spanish populations of rosemary were cultivated in two experimental fields and their essential oil composition monitored during two years. The main compounds present in the essential oils were camphor (21.9%), α-pinene (14.8%), 1,8-cineole (11.6%), β-pinene + myrcene (11.3%) and camphene (8.3%), although their proportions differ greatly among populations. Other terpenes as limonene had a significant presence in some populations, up to 10.2%. The results showed that the variability in the composition of essential oil was mainly controlled by genetics and little affected by soil and climate conditions. Statistical processing allowed to group populations into three different groups based on the geographical origin of the populations. In conclusion, the characterization of essential oils of these populations is a starting point for the development of breeding programmes aimed to commercialize standardized plants (varieties).