Strain of Rhizobium lupini determines natural abundance of 15N in root nodules of Lupinus spp

• Published in: Soil biology & biochemistry 1986, Vol.18 (1), p.97-101
• Main Authors: Bergersen, F.J., Turner, G.L., Amarger, Noelle, Mariotti, Francoise, Mariotti, A.
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Life Sciences; Lupinus albus; Lupinus luteus; Microbial ecology; nitrogen fixation; Rhizobium lupini; root nodules; Soil; Soil study; strains; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...)
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/0038-0717(86)90109-4

Discrepancies between French and Australian results in measurement of the natural enrichment of 15N in nodules of Lupinus spp were due to the strains of Rhizobium lupini used. The Australian inoculant strain, WU425, produced nodules enriched in 15N above values for the entire plants, on all lines of L. luteus and L. albus tested. The total nitrogen and the natural abundance of 15N in nodules produced by the French strain, LL13, were much lower. In tests in Australia and in France with L. luteus inoculated with 15 other strains of R. lupini from diverse origins, 9 produced nodules with elevated 15N abundance, but of these 8 were less than with strain WU425. Most strains producing 15N-enriched nodules were slower-growing on yeast extract-mannitol agar; most faster-growing strains produced little or no nodular 15N enrichment. For strains with 15N-enriched nodules, enrichment increased with increasing nodule N·plant −1, and shoot nitrogen tended to be depleted in 15N. There was no relationship between symbiotic effectiveness of strains (mg N 2 fixed·plant −1) and 15N enrichment of nodules.