Morphological evaluation and antioxidant activity of in vitro- and in vivo-derived Echinacea purpurea plants

An effective in vitro protocol for rapid clonal propagation of Echinacea purpurea (L.) Moench through tissue culture was described. The in vitro propagation procedure consisted of four stages: 1) an initial stage - obtaining seedlings on Murashige and Skoog (MS) basal medium with 0.1 mg L-1 6-benzylaminopurine, 0.1 mg L-1 alpha-naphthalene acetic acid and 0.2 mg L-1 gibberellic acid; 2) a propagation stage - shoot formation on MS medium supplemented with 1 mg L-1 6-benzylaminopurine alone resulted in 9.8 shoots per explant and in combination with 0.1 mg L-1 alpha-naphthalene acetic acid resulted in 16.2 shoots per explant; 3) rooting stage - shoot rooting on half strength MS medium with 0.1 mg L-1 indole-3-butyric acid resulted in 90% rooted microplants; 4) ex vitro acclimatization of plants. The mix of peat and perlite was the most suitable planting substrate for hardening and ensured high survival frequency of propagated plants. Significant higher levels were observed regarding water-soluble and lipid-soluble antioxidant capacities (expressed as equivalents of ascorbate and alpha-tocopherol) and total pnenols content in extracts of Echinaceae flowers derived from in vitro propagated plants and adapted to field conditions in comparison with traditionally cultivated plants.