当前位置： SCI文献检索 > Frontiers in Microbiology期刊下所有文献 > Selection of Competitive and Efficient Rhizobia Strains for White Clover.

Selection of Competitive and Efficient Rhizobia Strains for White Clover.

Abstract：

:The practice of inoculating forage legumes with rhizobia strains is widespread. It is assumed that the inoculated strain determines the performance of the symbiosis and nitrogen fixation rates. However, native-naturalized strains can be competitive, and actual nodule occupancy is often scarcely investigated. In consequence, failures in establishment, and low productivity attributed to poor performance of the inoculant may merely reflect the absence of the inoculated strain in the nodules. This study lays out a strategy followed for selecting a Rhizobium leguminosarum sv. trifolii strain for white clover (Trifolium repens) with competitive nodule occupancy. First, the competitiveness of native-naturalized rhizobia strains selected for their efficiency to fix N2 in clover and tagged with gusA was evaluated in controlled conditions with different soils. Second, three of these experimental strains with superior nodule occupancy plus the currently recommended commercial inoculant, an introduced strain, were tested in the field in 2 years and at two sites. Plant establishment, herbage productivity, fixation of atmospheric N2 (15N natural abundance), and nodule occupancy (ERIC-PCR genomic fingerprinting) were measured. In both years and sites, nodule occupancy of the native-naturalized experimental strains was either higher or similar to that of the commercial inoculant in both primary and secondary roots. The difference was even greater in stolon roots nodules, where nodule occupancy of the native-naturalized experimental strains was at least five times greater. The amount of N fixed per unit plant mass was consistently higher with native-naturalized experimental strains, although the proportion of N derived from atmospheric fixation was similar for all strains. Plant establishment and herbage production, as well as clover contribution in oversown native grasslands, were either similar or higher in white clover inoculated with the native-naturalized experimental strains. These results support the use of our implemented strategy for developing a competitive inoculant from native-naturalized strains.

journal_name

Front Microbiol

journal_title

Frontiers in microbiology

authors

Irisarri P,Cardozo G,Tartaglia C,Reyno R,Gutiérrez P,Lattanzi FA,Rebuffo M,Monza J

doi

10.3389/fmicb.2019.00768

subject

Has Abstract

pub_date

2019-04-23 00:00:00

pages

768

issn

1664-302X

journal_volume

pub_type

杂志文章

在线工具

Selection of Competitive and Efficient Rhizobia Strains for White Clover.