Selection of Competitive and Efficient Rhizobia Strains for White Clover

Conclusion This study provides proof of concept for a strategy to select inoculants with high competitive ability under field conditions for regions with introduced exotic legumes and their symbionts. Native-naturalized rhizobia strains selected by their N fixation efficiency, showed greater nodule occupancy than the currently used commercial introduced strain, independent of soil type, and of previous history of inoculation. Most importantly, the differences in nodule occupancy between the selected native-naturalized strains and the commercial one remained when assessed under field conditions at two sites and in two sowing years, being greatest for nodules from stolons. These organs, that are essential for white clover performance as they replace primary roots and thus white clover persistence via vegetative propagation, depend entirely on soil rhizobia for its nodulation. Plant establishment, herbage production and N fixed per unit plant biomass were either similar or higher when white clover was inoculated with the experimental native-naturalized strains than with the currently used commercial strain. Author Contributions JM and MR conceived the project. GC and RR executed the field assays and PG and CT laboratory experiments. PI wrote the first draft of the manuscript. FL rewrote it. All authors contributed to the statistical analysis, manuscript revision, and final version. Funding This study was funded by INIA, FPTA Project No. 295, PEDECIBA aliquots to JM and PI a...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research