Production of isoflavonoids in callus cultures of Pueraria candollei var. mirifica.

Pueraria candollei Wall. ex Benth. var. mirifica (Airy Shaw & Suvat.) Niyomdham was investigated for callus induction using Murashige and Skoog (MS) medium containing different plant growth regulators. After 8 weeks of culture, 66-100% of leaf or stem explants formed calli. Calli from stem explants cultured on MS medium supplemented with 0.5 mg/l thidiazuron (TDZ) gave the maximum of shoot induction (16%) and the highest level of total isoflavonoids [(50.39 +/- 7.06) mg/g dry wt], which was 7-fold higher than that of the native tuber [(7.04 +/- 0.29) mg/g dry wt]. These results suggest that addition of TDZ to the culture medium markedly enhances the production of isoflavonoids in calli induced from stem explants of P. candollei var. mirifica.