Effect of Plant Growth Regulators and Light on Callus Induction, Antioxidant Enzyme Response and Total Phenol in Nigella arvensis L.

The tissue culture of Nigella arvensis L. was carried out on an MS medium supplemented with various concentrations of auxins and cytokinins. Media fortified with different concentrations (0.0, 0.5, 1.0 and 1.5 mg/L) of 2, 4-D, NAA or IBA in combination with kinetin or BAP (1.5 mg/L and 2 mg/L) were used to induce and grow callus in present and absent of light. The experimental design was performed as a randomized block factorial design with three replications. Following callus culture, antioxidant enzymes activity and total phenolic contents were evaluated. The maximum callus induction (80.9%) was obtained with 1.0 mg/L 2, 4-D and 1.5 mg/L/ kinetin in the presence of light. Plant growth regulators combination and concentration, as well as photoperiod, affected the activity of antioxidant enzymes. The highest activities of catalase and peroxidase and total phenolic contents were measured in media with BAP combinations. On the contrary, the activity of superoxide dismutase was at the least in all BAP combinations. Overall, light intensified the activities of enzymes, but it had a negative effect on total phenolic contents.