Effect of Macronutrients, Cytokinins and Auxins, on in Vitro Organogenesis of Thymus vulgaris L.

The present study reports an efficient protocol for in vitro propagation of Thymus vulgaris L., an aromatic and medicinal plant in Morocco. Initially, we performed in vitro multiplication of Thymus vulgaris explants existing in the laboratory and obtained from micropropagation by shoot tip culture. Afterwards, we have evaluated the effect of six macronutrients. After that, seven cytokinins (Kin, BAP, 2iP, DPU, Adenine, Zeatine and TDZ) in three different concentrations (0.46, 0.93, 2.32 μM) have been evaluated to optimize cultures multiplication and elongation. Moreover, the effect of three auxins (IAA, IBA and NAA) at 0.57 μM, combined to 4 cytokinins (Kin, BAP, DPU and Ad.) at 0.46 μM, on shoot rooting has been studied. Thereby, MS medium has been proved the most favorable for plantlets growing. Also, we found that the addition of certain cytokinins, specifically 0.46 Kin, 0.46 and 0.93 BAP, 0.46 2iP, 0.46 DPU, 0.46 Ad. and 0.46 Zeat., ensures better multiplication and growth of vitroplants. In addition, multiplication and rooting of cultures were well optimized after addition 0.46 Kin + 0.57 IAA or NAA, 0.46 DPU + 0.57 IBA and 0.46 Ad. + 0.57 IBA combinations to the culture medium. Lastly, plantlets with roots were successfully acclimatized to ex-vitro conditions and these latter served as a source to establish in vitro culture again.