Abstract
Competition between indigenous Rhizobium leguminosarum biovar trifolii strains and inoculant strains or between mixtures of inoculant strains was assessed in field and growth-room studies. Strain effectiveness under competition was compared with strain performance in the absence of competition. Field inoculation trials were conducted at Elora, Ontario, Canada, with soil containing indigenous R. leguminosarum biovar trifolii. The indirect fluorescent-antibody technique was used for the identification of nodule occupants. Treatments consisted of 10 pure strains, a commercial peat inoculant containing a mixture of strains, and an uninoculated control. Inoculant strains occupied 17.5 to 85% of nodules and resulted in increased dry weight and nitrogen content, as compared with the uninoculated control. None of the strains was capable of completely overcoming resident rhizobia, which occupied, on average, 50% of the total nodules tested. In growth-room studies single commercial strains were mixed in all possible two-way combinations and assessed in a diallel mating design. Significant differences in plant dry weight of red clover were observed among strain combinations. Specific combining ability effects were significant at the 10% level, suggesting that the effectiveness of strain mixtures depended on the specific strain combinations. Strains possessing superior effectiveness and competitive abilities were identified by field and growth-room studies. No relationship was detected between strain effectiveness and competitive ability or between strain recovery and host cultivar. The concentration of indigenous populations was not considered to be a limiting factor in the recovery of introduced strains at this site.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Amarger N., Lobreau J. P. Quantitative study of nodulation competitiveness in Rhizobium strains. Appl Environ Microbiol. 1982 Sep;44(3):583–588. doi: 10.1128/aem.44.3.583-588.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Demezas D. H., Bottomley P. J. Influence of Soil and Nonsoil Environments on Nodulation by Rhizobium trifolii. Appl Environ Microbiol. 1987 Mar;53(3):596–597. doi: 10.1128/aem.53.3.596-597.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Handelsman J., Brill W. J. Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti. Appl Environ Microbiol. 1985 Apr;49(4):818–821. doi: 10.1128/aem.49.4.818-821.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnston A. W., Beringer J. E. Mixed inoculations with effective and ineffective strains of Rhizobium leguminosarum. J Appl Bacteriol. 1976 Jun;40(3):375–380. doi: 10.1111/j.1365-2672.1976.tb04186.x. [DOI] [PubMed] [Google Scholar]
- Li D. M., Alexander M. Bacterial Growth Rates and Competition Affect Nodulation and Root Colonization by Rhizobium meliloti. Appl Environ Microbiol. 1986 Oct;52(4):807–811. doi: 10.1128/aem.52.4.807-811.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Materon L. A., Hagedorn C. Competitiveness of Rhizobium trifolii Strains Associated with Red Clover (Trifolium pratense L.) in Mississippi Soils. Appl Environ Microbiol. 1982 Nov;44(5):1096–1101. doi: 10.1128/aem.44.5.1096-1101.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meade J., Higgins P., O'gara F. Studies on the Inoculation and Competitiveness of a Rhizobium leguminosarum Strain in Soils Containing Indigenous Rhizobia. Appl Environ Microbiol. 1985 Apr;49(4):899–903. doi: 10.1128/aem.49.4.899-903.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- VINCENT J. M., WATERS L. M. The influence of the host on competition amongst clover root-nodule bacteria. J Gen Microbiol. 1953 Dec;9(3):357–370. doi: 10.1099/00221287-9-3-357. [DOI] [PubMed] [Google Scholar]