Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Competitive abilities of common field isolates and a commercial strain of Rhizobium leguminosarum bv. trifolii for clover nodule occupancy
Author: Denton, M.
Reeve, W.
Howieson, J.
Coventry, D.
Citation: Soil Biology & Biochemistry, 2003; 35(8):1039-1048
Publisher: Pergamon-Elsevier Science Ltd
Issue Date: 2003
ISSN: 0038-0717
Abstract: We previously reported that commercial Rhizobium leguminosarum bv. trifolii inoculants failed to outcompete naturalized strains for nodule occupation of clover sown into an alkaline soil [Aust. J. Agric. Res. 53 (2002) 1019]. Two field isolates that dominated nodule occupancy at the field site were labeled with a PnifH-gusA marker. Marked strains were chosen on the basis that they were equally competitive and fixed similar amounts of nitrogen in comparison to their parental strain. The minitransposon insertions were cloned and sequence analysis revealed that neither lesion disrupted the integrity of any known gene. The marked strains were then used to follow nodule occupancy of Trifolium alexandrinum in competition against the commercial inoculant TA1 under a range of experimental conditions. In co-inoculation experiments in sand–vermiculite, TA1 outcompeted each marked field isolate for nodule occupancy. However, using TA1-inoculated seed sown into alkaline soil containing a marked field strain, it was demonstrated that by increasing the cell number of marked rhizobia in the soil and reducing the cell number of the commercial inoculant, the proportion of nodules occupied by TA1 was reduced. These studies indicate that the ability of the field isolates to dominate nodule occupancy in the alkaline field soils was most likely caused by poor commercial inoculant survival providing the advantage for naturalized soil rhizobia to initiate nodulation.
Keywords: Competition; GUS; Nitrogen fixation; Nodule occupancy; pH; Rhizobium; Trifolium
RMID: 0020030473
DOI: 10.1016/S0038-0717(03)00146-9
Description (link):
Appears in Collections:Earth and Environmental Sciences publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.