Direct and Indirect in vitro Regeneration of Plantlets of Digitalis lanata and D. purpurea Species

Foxglove (Digitalis sp.), as an ornamental and medicinal plant, is used for treatment of heart congestive disorders. Use of plant cell and tissue culture can be effective in large scale micropropagation and stable production of medicinal compounds. In this study direct and indirect regeneration methods in two species of this genus (D. purpurea and D. lanata) were investigated in response to different concentrations of auxin and cytokinin. In indirect method (regeneration through callus), regeneration occurred only in D. lanata in response to 3mg L-1 BAP, and no regeneration observed in callus of D. purpurea. Use of 13 different combinations of plant growth regulators for direct regeneration from node explants showed that the best regeneration in both species occurred in MS medium supplemented by BAP. Number of shoots produced in direct method in D. purpurea was more than that of D. lanata.  The response of explants of D. lanata to different treatments was faster. The results showed that phenol production in node culture of both species was much less than leaf culture in indirect regeneration. Rooting was rapidly achieved even in mediums without auxins and 1 mg L-1 Zeatin. Rooted plantlets transported into the soil and acclimated in greenhouse. Taking to the account of low phenol production and high number of shoots in direct regeneration, this method could be suggested for the micropropagation of foxglove.