Effect of calcium, manganese and lithium on growth and cardenolide content in cell suspension cultures of Digitalis thapsi L.

Cell suspension cultures of Digitalis thapsi were grown in Murashige and Skoog medium under continuous light. The effects of the absence of CaCl2, elevation of the MnSO4 concentration from 0.1 mM to 5 mM or the addition of 100 μM LiCl on their growth and digoxin production were investigated. The elimination of calcium reduced growth and viability of cultures but promoted digoxin formation. An increase of the MnSO4 concentration or the addition of LiCl resulted in higher digoxin content. Under such conditions growth was not affected.