Determination of morphogenetic variability in essential oil ratio and components of Origanum syriacum L. var. bevanii (Holmes) Ietswaart

of morphogenetic variability in ABSTRACT The aim of this study was to determine changes in the essential oil ratio and the essential oil components of the position of leaves on the stem and the aerial parts (stem, leaf, and flower) at O. syriacum L. var. bevanii (Holmes) Ietswaart. which naturally grows in Anatolia. It was conducted in 2016 growing session, under the Diyarbakır conditions (South-eastern Anatolia, Turkey). Plants were harvested at the full flowering time and then the plant samples were separated into the leaves (according to node numbers on the stem (from top to base)), stems and flowers and dried under room conditions in the shade. The essential oils were isolated from the dry samples and were analyzed by means of GC-MS. The highest rate of essential oil was found in flowers (4.26%). The ratio of essential oil in leaves (2.76-3.10%) was determined to the higher in the upper leaves than in the middle and lower leaves. There was little change in leaf sizes on the 7 th node and the next. The essential oil components varied according to the node numbers of the leaves. The highest ratio of carvacrol was determined in the stem (66.99%) and the carvacrol ratio of the leaves (58.39-64.53%) increased up to the 4 th node leaves.