Abstract
Inoculation of beans (Phaseolus vulgaris L.) with strains of R. tropici IIB and R. etli resulted in the disappearance of the R. tropici IIB stains from the nodule population and their replacement by other (non R. tropici IIB) bean symbionts (Vlassak et al. 1996). Coinoculation studies in monoxenic conditions and in soil core microcosms with plants harvested at two different growth stages indicated that the inoculated R. tropici IIB strains CIAT899 and F98.5 possess a good intrinsic competitiveness which declines, however, at a later plant growth stage and in soil conditions. The poor saprophytic competence of R. tropici IIB strain CIAT899 was further demonstrated by its poor survival in soil core microcosms after bean harvest. Strains were isolated from the field plots with a 3-year bean-planting history, characterized and evaluated for their competitiveness against R. tropici IIB strain CIAT899. Isolates from field plots, which had been repeatedly inoculated with R. tropici IIB strain CIAT899, showed a higher nodule occupancy compared to R. tropici IIB strain CIAT899, and this higher competitiveness exhibited by the field isolates might be an additional reason for the poor performance of R. tropici IIB strain CIAT899 in the field study. Plots with and without a history of bean production revealed after 3-year bean cultivation an almost totally different population that also significantly differed in competitiveness.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 12 February 1996
Rights and permissions
About this article
Cite this article
Vlassak, K., Mercante, F., Straliotto, R. et al. Evaluation of the intrinsic competitiveness and saprophytic competence of Rhizobium tropici IIB strains. Biol Fertil Soils 24, 274–282 (1997). https://doi.org/10.1007/s003740050243
Issue Date:
DOI: https://doi.org/10.1007/s003740050243