The effect of triacontanol on micropropagation and on secretory system of Thymus mastichina

Shoot multiplication of Thymus mastichina L. was achieved on media containing 0.1 mg l−1 6-benzyladenine and/or 0.1 mg l−1 indole-3-butyric acid, or in hormone-free medium (control). The growth of plantlets, the production and composition of the essential oil, the density and secretory stage of glandular hairs have been evaluated in the presence and absence of growth regulators and triacontanol. We observed a positive effect of triacontanol on the growth of micropropagated plantlets using different conditions. Media with different levels of BA, IBA and TRIA resulted in no differences in the composition of the essential oil produced by plantlets. The major components of the oil were 1,8-cineole and linalool. An increase in the oil yield was observed especially when triacontanol was added to hormone-free medium. There was no correlation between changes in the oil yield and glandular hairs density, but the yield was dependent on the secretory stage of the glands.