GROWTH-BEHAVIOR AND IAA PRODUCTION BY A RHIZOBIUM SP. ISOLATED FROM ROOT-NODULES OF A LEGUMINOUS MEDICINAL HERB, DOLICHOS BIFLORUS. L., IN CULTURE

A Rhizobium sp. isolated from the root nodules of a leguminous medicin al herb Dolichos biflorus. L., was found to produce large amounts of i ndole acetic acid (IAA) (139.1 mu g/ml) from L-tryptophan supplemented basal medium. The Rhizobium sp. was a fast growing species which reac hed its stationary phase of growth and IAA production at 24 h. An enri chment of the carbon - free incubation medium with sucrose (1%), cytok inin (20 mu g/ml) and KNO3 (0.2%) promoted the IAA production by 424.3 8% over control. The possible role of the rhizobial production of IAA on the rhizobia - legume symbiosis is discussed.