Origanum vulgare L. is a commercially valued species with remarkable biological properties. It is subject to over-exploitation practices that seriously threaten its sustainability for future generations. Thus, micropropagation serves as a tool for the protection and domestication of this species. In this

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.

No abstract

Here, we describe an efficient and rapid protocol for the micropropagation of Thymus pallidus Cosson ex Batt., a very rare medicinal and aromatic plant in Morocco. After seed germination, we tested the effect of different macronutrients, cytokinins alone or in combination with gibberellic acid (GA 3) or auxins, on T. pallidus plantlet growth. We found that Margara macronutrients (N 30 K) had the best effect on the in vitro development of the plantlets. The addition of 0.93 µM/L 1,3-diphenylurea (DPU), 0.46 µM/L adenine (Ad), and 0.46 and 0.93 μM/L kinetin (Kin) resulted in the best shoot multiplication and elongation. In addition, the combination of 0.46 µM/L Kin, DPU, or Ad with gibberellic acid, in particular, 0.46 µM/L Ad + 0.58 µM/L GA 3 and 0.46 µM/L Kin + 1.15 µM/L GA 3 , led to better bud and shoot multiplication. Moreover, the integration of the combinations of 0.46 μM/L Kin and auxins, namely 0.46 µM/L Kin + 2.85 µM/L indole-3-acetic acid (IAA), 0.46 µM/L Kin + 2.85 or 5.71 µM/L indole-3-butyric acid (IBA), and 0.46 µM/L Kin + 0.3 or 0.57 µM/L 1-naphthaleneacetic acid (NAA), in the culture medium led to better root development and optimized aerial growth. Finally, the in vitro plants from the medium containing N 30 K + 0.46 µM/L Kin + 2.85 µM/L IAA were successfully acclimatized; these plants served as a source for repeating in vitro culture.

Origanum compactum Benth., a species endemic to Morocco characterized by its biological activities, is overexploited because of its commercial value and threatened with extinction. Accordingly, measures for its conservation are needed. Micropropagation serves as a solution for the protection and the domestication of this species.