Evaluation Role of Activated Charcoal and Growth Regulators on Enhancement of Thymus Capitatus Micropropagation

Abstract

Due to the presence of bioactive compounds that have medicinal uses, the thyme plant (Thymus capitatus) is under increasing pressure. The population has continuously declined due to this pressure, which puts it at risk of depletion and extinction. The aim of this study is to identify effective ways to preserve this plant in vitro using plant tissue culture technique, as well as to pinpoint the key factors that contributed to its successful vegetative propagation, rooting, and acclimatization. Plant materials were collected from the Al-Shaafiyin region, followed by surface sterilization. They were then cultured on a medium supplemented with a combination of the growth regulators BA and NAA along with activated charcoal for vegetative propagation, another combination of IBA, NAA, and activated charcoal for rooting, and a separate formulation for plant acclimatization. The results showed that the best treatment for obtaining vegetative growth was the use of activated charcoal, which significantly outperformed all other treatments in terms of plant height, number of leaves, and number of branches, recording values of 3.03 cm, 76.4 leaves, and 5.5 branches, respectively.

This is attributed to its ability to absorb growth-inhibiting substances. The results also indicated that activated charcoal was the most effective treatment for root development, showing a significant superiority over the other treatments, with an average of 5 roots and a root length of 6.2 cm. Activated charcoal improved the properties of the growth medium by adsorbing inhibitory compounds and providing a phenol-free environment conducive to root development. Furthermore, the experiment demonstrated that a 1:1 (v/v) mixture of soil and peat moss resulted in the highest plant survival rate (80%), which is likely due to the balanced physical and chemical properties of the mixture. The use of activated charcoal in micropropagation programs is recommended due to its effectiveness in enhancing both shoot and root development, thereby creating a more favorable environment for plant tissue growth. It is also advisable to avoid culture media lacking activated charcoal. For the acclimatization stage, a 1:1 (v/v) mixture of soil and peat moss is recommended, as it provides adequate aeration, moisture retention, and essential nutrients necessary for plant survival.