Study of the effect of different antioxidants in reducing the browning of callus and its biomass production in two species of licorice

 The roots and stolons of Glycyrrhiza species constitute one of the most important crude drugs in the world and contain a large amount of glycyrrhizin, an oleanane-type triterpenoid saponin. Tissue culture and callus production in licorice species are prerequisites for studies on secondary metabolites and cell transformation. In order to effect of antioxidant to reduce the browning and growth of callus, was used Ascorbic Acid and PVP in different levels. Also in order to influence these antioxidants in the callus growth index, were cultured both species as cell suspension. Callus was produced from hypocotyl related to two weeks’ seedlings. Callus was induced from NAA (0.5 mg/L) and BA hormones (2 mg/L) as well as ascorbic acid and PVP treatments at different concentrations as two separated factorial experiments based on CRD design. The results showed that in consecutive sub culture 1200 mg/L of PVP had the least generation, necrosis and the most callus production in both species. Whereas, in cell suspension, with increasing PVP concentration, was decreased callus growth index and 1200 mg/L PVP has shown the lowest callus growth index in both species. It can be said that PVP absorb NAA and BA hormones in cell suspension and therefore it was reduced concentration of hormones in medium. Ascorbic acid treatment with 80 and 100 mg/L had the highest callus growth index in both species respectively and it is recommended for cell suspension culture in licorice.