Minimal lethal concentration of hyrgromycin B in calli induction and shoot multiplication process of <i>Digitalis purpurea</i> L.

Abstract

The plants of the genus Digitalis are characterized by the production of cardenolides, drugs widely used worldwide in the treatment of heart failure. In previous research a transformation protocol was developed from leaf disc of Digitalis purpurea L., using geneticin as selection marker. However some escapes in the selection process were obtained. So it is necessary to develop a more efficient selection scheme using another selective agent. Therefore, the aim of the present research was to select the minimum lethal concentration of hygromycin B during callus induction and shoots multiplication of D. purpurea. For callus induction we studied five concentrations of hygromycine B (3, 6, 9, 12, 15 mg l-1) during 28 days. Besides, the effect in shoot multiplication of four concentrations of hygromycine B (25, 50, 75, 100 mg l-1) was studied during 30 days. The minimal lethal concentration for callus formation was 12 mg l-1. In the case of shoot multiplication, 100% mortality was showed at 75 mg l-1 strictly after 30 days. The proposed selection scheme is recommended for future work at genetic transformation in this species. Keywords: cardenolides, genetic transformation, hpt, selection