Optimization of Callus Induction and Shoot Regeneration in Two Safflower (Carthamus tinctorius) Cultivars

Safflower (Carthamus tinctorius), as one of the most important economic products in the world, has one of the highest quality edible oils. Safflower cultivars are hardy plants compared to other plants due to different methods of tissue culture and regeneration. Therefore, it is necessary to provide a high efficiency method for the regeneration of safflower commercial cultivars. In this study, the effect of different concentrations of BAP, Kin and TDZ on callus induction and shoot regeneration of hypocotyl and cotyledon explants for two safflower cultivars (Soffeh and Golmehr) in different concentrations of BAP, Kin, TDZ and NAA (0, 0.2, 0.5 and 1 mg/l) were evaluated. The results showed that the highest frequency of shoot regeneration also was obtained on MS medium supplemented with 0 mg/l NAA and 1 mg/l TDZ (33%) from cotyledon explant of Golmehr cultivar. There was a significant difference between cultivar’s shooting, Golmehr cultivar showed a better shooting percentage. Finally, shoots were transferred to eight different rooting media. The best medium for rooting was MS medium supplemented with IBA (2 mg/l) + sucrose (2%) + agar (7%). The results showed that Golmehr cultivar was better than Soffeh cultivar in terms of regeneration and response to optimization.