Symbiosis between Rhizobium and the non-legume, Polypleurum wallichii

Abstract

Polypleurum wallichii is an aquatic plant found in East- Khasi Hill District of Meghalaya, in the Northeast India. The endophyte was successfully cultured using Tryptone-yeast medium. Holdfast as well as thallus showed Gram-negative bacterium resembling the bacterioids of Rhizobium, (designated as Polypleurum type-I) similar to nodules from Glycine max and other tropical leg-umes. The plant body of Polypleurum has poor vasculature and lack intercellular space, hence, no formation of distinct nodules. The observations indicate that the plant is a nitrogen fixing non-legume, and the endophyte bacterium is member of Rhizobium