Efficient regeneration and antioxidant potential in regenerated tissues of Piper nigrum L.

The organogenic potential and antioxidant potential (1, 1-diphenyl-2-picrylhydrazyl-scavenging activity) of the medicinal plant Piper nigrum L. (black pepper) were investigated. Callus induction and shoot regeneration were induced from leaf explants of potted plants cultured on MS medium supplemented with different plant growth regulators. The best callogenic response was observed on explants cultured for 30 days on MS medium supplemented with either 0.5 or 1.5 mg l(-1) 6-benzyladenine (BA) + 1.0 mg l(-1) alpha-naphthaleneacetic acid. Subsequent transfer of the callogenic explants onto MS medium supplemented with 1.5 mg l(-1) BA + 1.0 mg l(-1) gibberellic acid (GA(3)) achieved 85% shoot organogenesis after 30 days of culture. The maximum number (7.2) of shoots/explant was recorded for explants cultured in MS medium supplemented with 1.0 mg l(-1) BA. Following the transfer of shoots to an elongation medium, the longest shoots (5.4 cm) were observed on MS medium supplemented with 1.0 mg l(-1) BA + 1.0 mg l(-1) GA(3). The elongated shoots were rooted on MS medium supplemented with different concentrations of indole butyric acid. An assay of the antioxidant potential of the in vitro-grown tissues revealed that the antioxidant activity of the regenerated shoots was significantly higher than that of callus and the regenerated plantlets.