Publications des scientifiques de l'IRD

Bakhoum N., Galiana A., Le Roux C., Kane A., Duponnois Robin, Ndoye F., Fall D., Noba K., Sylla S. N., Diouf D. (2015). Phylogeny of nodulation genes and symbiotic diversity of Acacia senegal (L.) Willd. and A. seyal (Del.) Mesorhizobium strains from different regions of Senegal. Microbial Ecology, 69 (3), p. 641-651. ISSN 0095-3628.

Titre du document
Phylogeny of nodulation genes and symbiotic diversity of Acacia senegal (L.) Willd. and A. seyal (Del.) Mesorhizobium strains from different regions of Senegal
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000351228900017
Auteurs
Bakhoum N., Galiana A., Le Roux C., Kane A., Duponnois Robin, Ndoye F., Fall D., Noba K., Sylla S. N., Diouf D.
Source
Microbial Ecology, 2015, 69 (3), p. 641-651 ISSN 0095-3628
Acacia senegal and Acacia seyal are small, deciduous legume trees, most highly valued for nitrogen fixation and for the production of gum arabic, a commodity of international trade since ancient times. Symbiotic nitrogen fixation by legumes represents the main natural input of atmospheric N-2 into ecosystems which may ultimately benefit all organisms. We analyzed the nod and nif symbiotic genes and symbiotic properties of root-nodulating bacteria isolated from A. senegal and A. seyal in Senegal. The symbiotic genes of rhizobial strains from the two Acacia species were closed to those of Mesorhizobium plurifarium and grouped separately in the phylogenetic trees. Phylogeny of rhizobial nitrogen fixation gene nifH was similar to those of nodulation genes (nodA and nodC). All A. senegal rhizobial strains showed identical nodA, nodC, and nifH gene sequences. By contrast, A. seyal rhizobial strains exhibited different symbiotic gene sequences. Efficiency tests demonstrated that inoculation of both Acacia species significantly affected nodulation, total dry weight, acetylene reduction activity (ARA), and specific acetylene reduction activity (SARA) of plants. However, these cross-inoculation tests did not show any specificity of Mesorhizobium strains toward a given Acacia host species in terms of infectivity and efficiency as stated by principal component analysis (PCA). This study demonstrates that large-scale inoculation of A. senegal and A. seyal in the framework of reafforestation programs requires a preliminary step of rhizobial strain selection for both Acacia species.
Plan de classement
Sciences du monde végétal [076] ; Biotechnologies [084]
Description Géographique
SENEGAL
Localisation
Fonds IRD [F B010064061]
Identifiant IRD
fdi:010064061
Contact