[Deformation of lucerne root hairs caused by the growth substances and culture broth filtrates of Rhizobium meliloti].

Deformation of lucerne root hairs caused by the action of beta-indolylacetic acid (IAA) and alpha-naphthylacetic acid (NAA) differs from deformation induced by Rhizobium meliloti. High concentrations of IAA brought about abnormal deformation of root hairs wherease the action of average concentrations of IAA resulted in corkscrew-like winding and wavy structures. No deformation was observed under the action of low IAA concentrations or the cultural broth of Rhizobium. Infective filaments in root hairs were found only upon infection with pure cultures of Rhizobium.