Change in total phenolic content and antibacterial activity in regenerants of Vitex negundo L

Abstract

A valuable medicinal plant, Vitex negundo L. has been investigated for its regeneration potential using shoot tip explants. Out of a range of concentrations of cytokinins [6-benzyl adenine (BA), 6-furfurylaminopurine, 2-isopentenyl adenine] used as supplement to Murashige and Skoog medium (MS), BA at 5. 0 μM concentration proved best for multiple shoot induction yielding 3. 60 ± 0. 50 shoots after 8 weeks of culture. Inclusion of a low concentration of an auxin with optimal cytokinin concentration favoured shoot multiplication and the optimum response was observed on MS medium supplemented with BA (5. 0 μM) along with α Naphthalene acetic acid (0. 5 μM), where 65. 0 ± 1. 73 % cultures responded with a mean number of 4. 80 ± 0. 58 shoots per explants after 8 weeks of culture. Ex vitro rooting of in vitro derived microshoots was achieved upon dipping the cut ends of microshoots in 500 μM indole-3-butyric acid for 10 min followed by transfer to thermocol cups containing sterile soilrite. About 95 % of the plantlets survived the acclimatization procedure and were transferred to greenhouse and finally to field. Screening of the antibacterial activity and estimation of total phenolic content of ethanolic extracts of micropropagated plants were also carried out and compared with that of the mother plant. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.