Variations in essential oil yields and compositions of Salvia officinalis (Lamiaceae) at different developmental stages

Variations in the yield and composition of essential oil of Dalmatian sage ( Salvia officinalis L., Lamiaceae) in various stages of development were analyzed in two individuals (= genotypes) of different geographic origin. Both plants have been successfully grown ten years under identical environmental conditions in a private garden in Belgrade. The amount and composition of the oils were analyzed during one growing season starting from the young to old overwintered leaves. The results of the cluster analysis showed that leaf age and origin of the plants has a significant impact on the composition of the essential oils. All oil samples formed two main clades. The first clade are oils collected from young leaves from April to June and belong to α-humulene type. The second clade includes oil obtained mainly of old leaves, which were collected from August to June, and belonging to the camphor and thujone type. In the second clade samples originating from Ucka are completely separated from samples originating from Belgrade. Also, based on these analyzes showed that the same individual (the same genotype) during one growing season significantly change the chemical composition of the essential oils. Thus, it is possible to distinguish three different "phenological types of essential oils": young leaves ("yl-oils"), early old leaves ("early-ol-oils") and a late old leaves type ("late-ol-oils") . Analysis of the seasonal changes in the composition of the essential oils of Dalmatian sage is shown that different components have different dynamics and different directions of change in the concentration during the season.