Callus Induction and Direct Shoot Regeneration in Lepidium draba L. Explants

Lepidium drabathrough the production of anti-cancer and anti-microbial compound, sulforaphane, is considered a valuable medicinal plants.Therefore, optimization of in vitro tissue culture to facilitate genetic transformation and improvement of traits in this plant is important. This study was conducted, by cotyledon, stem and root explants inMSmedium in the form of two separate tests. Data were analyzed in a factorial experiment based on completely randomized design. In the first experiment with different concentrations of growth regulators NAA and BAP, the highest response rate, direct shoot regeneration rate and direct shoot generation were related to root explants. The highest root production rate and root generation were showed in cotyledons explants. 1 mgl-1 BAP without NAA induced the highest direct shoot generation in root explants. Cotyledons explants in 2 mgl-1 NAA and 0.5 mgl-1 BAP produced the highest Root production rate and the highest root generation. Callus induction rate and callus initiation of stem explants were more than others, but the callus regeneration rate in three studied explants showed no significant difference. The highest shoot generation from regenerated callus was observed in the cotyledons explants. The second experiment with a combination of different concentrations of 2,4-D and BAP, under the influence of two treatments darkness and 16h photoperiod was performed. The highest investigated traits was in the 16h photoperiod. Cotyledons and stem explants were showed the highest callus induction rate and leaf explants showed the greatest weight of callus; While the highest callus regeneration rate and callus growth rate were obtained from the root explants.From leaf explants, the highest callus weightwas obtained from 0.5 mgl-1 2,4-D with 3 mgl-1BAP and the most growth rate of callus was obtained from 0.5 and 1 mgl-1 2,4-D and 3 mgl-1BAP. Also the combination of 2 mgl-1 2,4-D with 2 mgl-1 BAP and 3 mgl-1 BAP, produced the highest callus regeneration in root explants.