Dear Microorganisms are found every where in different environmental conditions so the species of Bradyrhizobium yuanmingense can be available in different areas in the globe. Of course it need some experiment but very wide nthat cannot be managed easily.

Good luck

Thanks for the attempt.

There is no doubt that Microbes are found everywhere but all organisms are not the same. That is what the diversity analysis needed in terms of evolution, phylogenetic relationship and to know the impact of various factors including edaphic in shaping community structure and co-evolution of symbiotic micro and macro organisms. Perhaps the question was not understood properly and that might be due to different expertise.

Of the Bradyrhizobium species you mentioned I believe B. japonicum would be most widespread. This would probably be a function of the widespread use of soybean which has spread from Asia temperate dispersion centers to New World temperate zones and to tropical zones in South America and African continent. Based on this dispersion of crop the proliferation of symbiotic could be expected and the introduction to diverse soils would generate new types adapting to the distinctive environmental conditions.

Yes

Me too believe that B. japonicum and B. elkani are the widespread in the world.

Bradyrhizobium yuanmingense and B. japonium are the species of legume-root nodulating, endosymbiont nitrogen-fixing bacterium. I agree with Paul Reed Hepperly ans.

A recent paper published in Science (DOI: 10.1126/science.aap9516) showed that the ordinary OTU (OTU1) in the global soils was affiliated to Bradyrhizobium. I made a "blast" with the OTU1 on the database EzTaxon (https://www.ezbiocloud.net/identify) and it matched to B. elkanii.