Abstract
IN THE PRESENT study, growth regulators, sugars and antioxidants were investigated for their effect on callus growth, flavonoid content as well as the activity of some related enzymes in callus culture of Rumex vesicarius. The effect of Murashige and skoog media (MS) containing indole butyric acid (IBA), naphthalene acetic acid (NAA), or 2,4-dichlorophenoxy acetic acid (2,4-D) on callus induction from cotyledonary leaf and hypocotyl explants was investigated. Results revealed that the highest callus biomass (fresh and dry weights) was obtained at 0.5 mg l(-1) IBA using cotyledonary leaf explant. Both sucrose and fructose promoted a good callus dry mass, while the highest flavonoid content was enhanced with the medium supplemented with fructose. Citric acid was the best antioxidant in reducing the callus browning intensity and significantly inhibiting polyphenol oxidase (PPO) activity by 13.7%. Citric acid also increased the callus dry weight by 26% and total flavonoid content by 67% over control. In conclusion, in vitro culturing of medicinal plant, Rumex vesicarius, enables increase of the biomass production and the yield of its biologically active constituents.