Medicinal & Aromatic Plants
Open Access

Abstract

Rapid in Vitro Regeneration and Clonal Multiplication of Thymus Bleicherianus Pomel, a Rare and Threatened Medicinal and Aromatic Plant in Morocco

NORDINE Aicha and EL MESKAOUI Abdelmalek

This paper reports, for the first time, an efficient and reliable protocol for in vitro clonal propagation of T. bleicherianus, a rare aromatic and medicinal plant in Morocco. Initially, nodal explants collected from wild plant were used for in vitro culture establishment on Murashige and Skoog (MS) basal salts medium without plant growth regulators (PGR). Browning and contaminants were the major obstacles for in vitro culture establishment using explant derived from wild plants. To overcome this problem, the use of polyvinylpyrrolidone together with dark treatment decreased browning from 100 to 25%. The aseptic and living explants were then transferred into MS medium and all cultures were placed under light conditions. The cytokinin type and concentration were the most important factors affecting shoot multiplication. Axillary shoot bud proliferation was achieved using plant growth regulators, 6-benzylaminopurine, and kinetin and α-naphthalene acetic acid. A high number of shoot (6.39 ± 0.21) was obtained on MS medium supplemented with 4.44 μM of 6-benzylaminopurine. Regenerated shoots were rooted on plant growth regulators-free MS medium. Plantlets were successfully acclimatized to ex vitro conditions with a survival rate of 85%. All regenerated plants were morphologically identical to the mother plants. The in vitro culture system successfully established for T. bleicherianus offers a viable tool for mass micropropagation, multiplication and conservation of this very rare and threatened species.