Micropropagazione di Thymus capitatus

Thymus capitatus is a compact woody shrub, endemic to the Mediterranean region, with attractive pink flowers. Although conventional vegetative propagation of T. capitatus is currently used, micropropagation could be effective for rapid mass propagation of selected clones and would preserve wild plants. Shoot tips of T. capitatus cultured on a gelled MS medium, supplemented with 0.4 mg l-1 2-iP, were used as primary explants to establish in vitro culture. Axillary shoots produced on uncontaminated explants were excised and subcultured to increase the stock of shoot cultures. To determine the optimal medium for shoot multiplication, increasing concentrations (0, 0.4, 0.8, 1.6 e 3.2 mg l-1) of 2-iP and increasing concentrations (0, 0.4, 0.8 mg l-1) of IAA were tested in a factorial experiment. The highest multiplication rate (8.5 microshoots per explant) was obtained with the combination of 3.2 mg l-1 2-iP and 0.4 mg l-1 IAA. Five IAA concentrations (0, 0.4, 0.8, 1.6 e 3.2 mg l-1) were also tested to determine the optimum conditions for in vitro rooting of microshoots. A very high rooting percentage (95%) was achieved. IAA concentrations equal or higher than 0.8 mg l-1 increased the number of roots per microcutting. All rooted plantlets were successfully established in soil.