Influence of Magnetic Fields on Thymol Biosynthesis in Thymus vulgaris L. Callus Tissues

This study demonstrated the positive effect of the magnetic field (MF) on the germination of thyme Thymus vulgaris L. seeds, seedlings growth and initiated the callus from its stem parts. The results showed the success of cultured seedling stem pieces on Murashige and Skoog (MS) medium supported by Kinetin (K) and 2,4-Dichlorophenoxy acetic acid (2,4-D) with 0.5 and 1.0 mg/L respectively in high percentage of callus initiation, reaching 80%.

Exposure of thyme seeds to a magnetic field led to a high germination rate and seedlings growth, Also, when exposed its stem pieces to MF for different periods led to an increase in the callus initiation percentage, reaching its highest 95% at a period of 60 minutes. The study also proved the effective role of the MF in stimulating the growth of callus cells to grow reaching to produce the secondary metabolic compounds by increasing the callus cells, oil content, accompanied by an increase in the percentage of thymol (the main component of thyme oil, which has medicinal benefits) recording the highest oil content of 3.49% and thymol content of 42.01% for callus cells exposed to MF at 60 minutes compared to the unexposed callus group (control) with 1.94% callus oil content and 38.98%  of thymol content.