Genetic diversity and phytochemical characterisation of Sideritis scardica populations from Greece

Sideritis scardica (Lamiaceae), commonly known as Mountain tea is endemic to Balkan countries and is an important medicinal and aromatic species. Lately, environmental and management factors resulted on decreasing of natural populations of Sideritis. Considering the risk of extinction of the species but also the demands of growers and consumers for high quality herbal products the present study aimed to evaluate the genetic and chemotypic diversity of S. scardica populations native to Greece. For this reason five populations (n = 20 to 25 individuals per population) were collected in 2018, from mountainous areas of N. Greece during the flowering period. After the evaluation of population size in situ, intra- and inter-population genetic diversity was determined in individual plants using SCoT molecular markers. High genetic diversity was detected within the studied populations. Additionally, the populations were highly differentiated based on SCoT markers. The qualitative volatile profile of the populations was developed through GC-MS analysis after simultaneous steam distillation and solvent extraction of composite herbal samples. Phytochemical analysis determined the presence of hydrocarbon, oxygenated monoterpenes and sesquiterpenes with most predominant: α- and β-pinene, α-campholenal, tr-pinocarveol, tr-verbenol, myrtenal, carvacrol, β-caryophyllene and caryophyllene oxide. Their quantitative composition varied among the populations. Our findings revealed that such diversity could substitute a great genetic pool for the selection of superior germplasm native to Greece for further exploitation in domestication and breeding programs of Sideritis species.