Leguminous Tree <I>Dalbergia lanceolaria</I> Linn. F. Bears Rhizobial Root Nodules

Abstract

Dalbergia lanceolaria, an economically and agriculturally important large leguminous tree possesses root nodules formed by a Gram negative bacterium which was identified to be a Rhizobium sp. The nodules are formed on younger roots of the tree mostly in the rainy seasons within 6-8 inches(15.25- 20.30 cm) under the soil. The nodules are spherical in shape, unbranched and loosely attached to the roots. The symbiont, a Rhizobium species, reaches its stationary phase of growth in a liquid medium in ten hours and is able to produce 39.2 μg/ml of Indole Acetic Acid in culture from L.tryptophan.