Lentil (Lens culinaris Medik.) nodulates with genotypically and phenotypically diverse rhizobia in Ethiopian soils. uri icon

abstract

  • Forty-eight lentil-nodulating rhizobia were isolated from soil samples collected from diverse agro-ecological locations in Ethiopia, and characterized based on 76 phenotypic traits. Furthermore, 26 representative strains were selected and characterized using multilocus sequence analyses (MLSA) of core (16S rRNA, recA, atpD, glnIl and gyrB) and symbiotic (nodA and nifH) genes. Numerical analysis of phenotypic characteristics showed that the 48 test strains fell into three major distinct clusters. The phylogenetic trees based on 16S rRNA genes showed that they belong to the Rhizobium genus. Our phylogenetic reconstruction based on combined gene trees (recA, atpD and glnlI) supported three distinct sub-lineages (Clades I-III). While genospecies I and II could be classified with Rhizobium etli and Rhizobium leguminosarum, respectively, genospecies III, might be an unnamed genospecies within the genus Rhizobium. Phylogenetic reconstruction based on the symbiosis-related genes supported a single cluster, indicating differences in the evolutionary histories between chromosomal and symbiotic genes. Overall, these results confirmed the presence of a great diversity of lentil-nodulating Rhizobium species in Ethiopia, inviting further exploration. Moreover, the differences in symbiotic effectiveness of the test strains indicated the potential for selecting and using them as inoculants to improve the productivity of lentil in the country. (C) 2016 Elsevier GmbH. All rights reserved.

publication date

  • 2017
  • 2017