Conservation of Thymus pallidus Cosson ex Batt. by shoot tip and axillary bud in vitro culture

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.

Clonal micropropagation of some species of the genus Thymus L.

“…Литературные данные, касающиеся исследований по клональному микроразмножению тимьяна, довольно противоречивы. Большинство ученых для выделения первичных эксплантов используют асептические проростки, полученные из семян (Banna, 2017;Bekircan et al, 2018;Kulpa et al, 2019;Ansari et al, 2020;Khajuria et al, 2021), которые у перекрестно опыляемых видов представляют генетически неоднородный материал. Известны исследования, касающиеся размножения T. persicus (Roniger ex Reach.…”

“…-1,0 мг/л БАП и 0,2 мг/л НУК (Nordine et al, 2014), а для T. vulgaris -2,0 мг/л БАП (Banna, 2017). Z. N. Ansari et al (2020) установили, что для T. pallidus Cosson ex Batt. максимальное количество побегов формировалось при использовании кинетина или аденина совместно с ГК 3.…”