Effects of individual selection on agronomical and morphological traits and essential oil of a “Greek basil” population

Abstract

“Greek basil” (Ocimum basilicum L.) is a common local cultivar in Greece, also known as “fine-leaved” basil, because of its small-narrow leaves. It is used mainly as ornamental plant in pots and gardens. Its variation in terms of the time of florescence and the shape of the vegetative development (compact or loose ball, reverse cone, other shapes) led to the improvement of a “Greek basil” population, by selecting plants with late blooming, compact ball shape and big size, potentially suited for ornamental uses. After three cycles of individual selection in nil competition conditions, by applying the above selection criteria, the florescence of the selected population started at the beginning of August, instead of mid June of the initial population, and the percentage of plants with compact ball shape increased from 55 to 90%. Moreover, significant variation was observed in the essential oil yield and composition due to the applied selection. The percentage oil yield increased from 0.15 to 0.53%. The main oil constituents eugenol and linalool raised from 8.60 to 12.90% (49%) and from 36.80 to 49.75% (34.90%) respectively, while the methyl (E) cinnamate, though it was present (19.20%) in the initial population, it was not even detected in the improved population.