Variability of the Genus Thymus L. in gene bank of Slovak Republic

In Slovakia found 28 species and 3 subspecies of the genus Thymus. Most genetic resources are the following species: T. pulegioides, T. praecox, T. pannonicus, T. capitata, and T. vulgaris. The aim of this study was to compare the genetic resources of the Thymus pulegioides L. samples, which were collected from different regions of Slovakia and the Czech Republic, stored in the Gene Bank of Slovakia. The evaluation of samples took five years 2009-2013. The size of the experiment was 3x30 m, genetic sources were planted in rows, 3 m each. The international descriptor (UPOV Thymus vulgaris L., 2002) was used for the evaluating of the morphological traits. The aerial parts of the plants have been harvested manually at the time of early flowering (June - July). Harvested material was dried at the room temperature of approximately 35 °C. Essential oil was isolated using very common method of steam distillation and the constituents of essential oil were analysed using GC-MS. The determinations were carried out according to the European Pharmacopoeia 8th edition (Ph. Eur. 8). The content of THD was determined using a colorimetric method with the Arnow reagent at 505 nm. The percentage contents of Total hydroxycinnamic derivatives (THD) were calculated and expressed as rosmarinic acid. As a result, from a morphological point of view, it was found that the diameter of the plant during cultivation reached 450-899 mm, stem length varied from 125 mm to 261 mm. The leaf blade length was measured in the 7.5-12.2 mm interval and the leaf blade width was from 4.6 mm to 7.5 mm. The coefficient of drying of raw materials interval was found 2.7-3.92. The content of THD expressed as rosmarinic acid varied from 2.11 to 8.0%. Was detected 5 linalool chemotypes, 2 geraniol-citral chemotypes, 1 geraniol chemotype, 5 car-vacrol chemotypes and 3 thymol chemotypes for T. pulegioides by the component composition of essential oil. This study confirmed high diversity of Thymus genus according to origin area, as well as morphological and phytochemical diversification within the species T. pulegioides due to the differences in the conditions of growing places.

genus Thymus, Thymus pulegioides L, gene bank, biodiversity, morphological marks, essential oil, total hydroxycinnamic derivatives