This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by MCNeil, D. L. Search for Related Content PubMed PubMed Citation Articles by MCNeil, D. L. Agricola Articles by MCNeil, D. L.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1982 September; 44(3): 647-652
Copyright © 1982, American Society for Microbiology. All Rights Reserved.

Variations in Ability of Rhizobium japonicum Strains To Nodulate Soybeans and Maintain Fixation in the Presence of Nitrate

University of Hawaii, Department of Agronomy and Soil Science, NifTAL Project, Paia, Maui, Hawaii 96779

ABSTRACT

This study investigated differences in sensitivity to nitrate of soybean (Glycine max cv. Davis) symbioses with 16 different Rhizobium japonicum strains. When nitrate (20 mM) was added to established symbioses, there were no significant differences in the degree of inhibition of acetylene reduction for any of the 16 strains. When nitrate was present during the establishment of nodules, high levels of nitrate (10 mM) were equally inhibitory on all symbioses, whereas specific strain effects appeared at low (0.5 mM) to medium (2.0 mM) levels of nitrate. At 1.5 mM nitrate in solution culture, the days to emergence of nodules varied from less than 10 (CB:1809, Nit61A118) to more than 16 (11 of 16 strains). In a clay-pot trial maintained at the low nitrate level (0.5 mM), symbioses with CB:1809 increased total nodule mass by 30% relative to nitrate-free controls. In the presence of 2.0 mM nitrate, CB:1809 maintained total nodule mass. For the remaining 6 strains tested, total nodule mass decreased to below the levels of the nitrate-free controls. In a separate clay pot trial, CB:1809 increased its competitive ability relative to USDA:110 when nitrate was added. If no nitrate was added, CB:1809 occupied 0.97 times as many nodules as USDA:110; when 10 mM nitrate was added, CB:1809 occupied 1.75 times as many nodules as USDA:110. Attempts to select nitrogen-adapted substrains of R. japonicum through sequential isolation and infection of plants grown on nitrate were not successful.

This article has been cited by other articles:

• Zahran, H. H. (1999). Rhizobium-Legume Symbiosis and Nitrogen Fixation under Severe Conditions and in an Arid Climate. Microbiol. Mol. Biol. Rev. 63: 968-989 [Abstract] [Full Text]