Abstract:
When sweet basil (Ocimum basilicum L.) leaves were cultured on Murashige and Skoog (MS) semi-solid medium comprised of 0, 0.5, 1 and 2 mg/l 2,4-D or NAA under light condition (20 µmol m-2 s-1) 16 h/day at 25°C for 4 weeks, it was found that all media containing 2,4-D or NAA could induce callus formation. Callus was light green and compact. Though medium fortified with NAA could solely induce callus formation, the obtained fresh weight of callus were less than 2,4-D treated callus. After callus had been transferred onto the same media for 4 weeks, results revealed that medium supplemented with 0.5 mg/l 2,4-D gave the highest fresh weight of callus in every week. Antioxidant content analysis showed that medium consisted of 0.5 mg/l 2,4-D had maximum β-carotene, ascorbic acid, phenolics and flavonoids in the first week which were 0.08 mg/gFW, 0.64 mg/gFW, 6.54 mg gallic acid/gFW and 7.38 mg rutin/gFW, respectively. Subsequent to evaluation of antioxidant ability via reducing power and DPPH free radical scavenging activity, there was an association between these activities with ascorbic acid and phenolics or flavonoids, respectively. For antioxidant content analysis in different leaf position of holy basil, lemon basil and sweet basil, it was found that β-carotene, ascorbic acid, phenolics and flavonoids are significantly different in different leaf positions. Even though most of antioxidant contents in fresh callus were less than natural leaf of sweet basil, some antioxidants in this callus were more than in the natural one such as ascorbic acid and flavonoids.