Callusogenesis and Organogenesis of Thymus Cultivars In Vitro

Abstract

The article is devoted to the in vitro cultivation of three Russian cultivars of two Thymus species (Th. vulgaris and Th. serpyllum) in order to study the possibility of induction of callusogenesis and organogenesis. The developed technology opens up prospects for the induction of somaclonal variability, obtaining the source material for breeding, as well as regeneration of thyme plants after genetic transformation. For the study, we used nutrient media based on the mineral composition of the Murashige and Skoog medium with the addition of auxin (indole-3-butyric acid, indole-3-acetic acid) and cytokinin (6-benzyladenine, kinetin) substances. For the induction of callusogenesis, the use of stem explants on nutrient media supplemented with 2,4-dichlorphenoxyacetic acid (1 or 2 mg/L) can be recommended. The efficiency of shoot organogenesis also depends on the type of explant, and its rather low values in most experimental variants are apparently due to the accumulation of endogenous auxins and phenolic compounds. Thus, a cultivar-specific morphogenetic response to the use of various phytohormones and growth regulators was established, as well as the influence of the explant type on the efficiency of morphogenic processes.