Genetic stable in vitro propagation by meristem culture and long-term conservation by cryogenic methods of endemic Thymus cilicicus Boiss. & Bal. germplasm

Phenolic compounds of Thymus spp (thyme) species of Lamiaceae family, which are very important in medicine, cosmetics and food industry, have attracted the attention of many researchers. However, studies on the thyme plant have generally focused on the identification of phenolic compounds and the evaluation of their microbiological effects. However, it is very important to protect and maintain this valuable plant diversity, which has a great secondary metabolite potential. In this sense, the genetic diversity of cultivated plants and their wild races should be protected and maintained as in situ or ex situ germplasm collections in a wide framework. In this study, the development of the most suitable environment for the clonal propagation of the explants of Thymus cilicicus, an endemic and medicinal aromatic plant, by the meristem culture method, in order to eliminate the losses that may occur in the characteristic properties of the parent material caused by the propagation by seed, was investigated in this study. Then, the genetic stability of the samples after in vitro clonal propagation was demonstrated by determining with ISSR primers. In in vitro preservation methods that provide relatively short-term storage, problems such as being uneconomical, requiring large areas, risk of contamination and somaclonal variation may be encountered. On the other hand, the cryopreservation method enables living cells and tissues to be stored in liquid nitrogen at -196°C for a long time without deterioration and is a suitable method for long-term preservation of plant germplasm in the field with minimum medium. In the current thesis study, according to the results obtained from the combinations of meristematic tissues, different media, plant growth regulators, activated charcoal taken from an endemic Thymus species, Thymus cilicicus plant, it was determined that the regeneration of semi-solid OM medium containing KIN and Charcoal was highly efficient. The duration of treatment with the PVS2 solution used during the cryopreservation process and how it affects regeneration and viability after thawing were investigated. It was determined that regeneration after cryopreservation was high in PVS2 solution treatment for 90 minutes after 0.4M sucrose preculture.