Characterization of 43 strains of Rhizobium leguminosarum biovars viciae, trifolii, and phaseoli was performed by two methodologies based on PCR amplification, i.e., PCR DNA fingerprinting of interrepeat sequences and restriction fragment length polymorphism (RFLP) analysis of PCR -amplified chromosomal and symbiotic gene regions. Groupings generated by PCR DNA fingerprinting with either extrag...

Soybean (Glycine max [L.] Merr.) establishes a symbiotic relationship by infection with soybeannodulating bacteria and subsequent root nodule formation. Soybean acquires atmospheric nitrogen as ammonia through the symbiotic nitrogen fixation by soybean-nodulating rhizobia in the root nodules. The inoculation of soybean with bradyrhizobia that has high ability of nitrogen fixation is considered ...

PCR-RFLP with nine restriction enzymes was applied to the 16S and 23S rRNA genes of 42 rhizobial and agrobacterial strains to determine the phylogenetic position of Rhizobium galegae and increase the understanding of the evolution of ribosomal operons. The strains were selected based on previous phylogenetic studies. PCR primers were designed so that they amplified a 2.3 kb fragment of the 23S ...

Mutualisms can be disrupted when non-native plants are introduced into novel environments, potentially impacting their establishment success. Introduced species reassemble mutualisms by forming associations with resident biota or maintaining familiar they co-introduced mutualists. Invasive Australian Acacia in South Africa have formed nitrogen-fixing rhizobium using both pathways. Here we exami...

Rhizobia induce root nodules and fix atmospheric N2 for most legume species in exchange for carbon. However, the diverse endophytic non-rhizobial bacteria in legume nodules that co-exist with rhizobia are often ignored because they are difficult to cultivate using routine cultivation approaches. To enhance our understanding of the incidence and diversity of legume-bacteria associations, a high-...

Previous research has shown that a significant limitation to the agricultural use of improved rhizobial inoculant strains is competition from the indigenous soil population. In this work, we sought to test whether chemical inhibitors of flavonoid-induced nod gene expression in Bradyrhizobium japonicum could be identified and utilized to affect interstrain competition for nodulation of soybeans....

Symbiotic nitrogen fi xation has important role in sustainable soybean production because of utilization of atmospheric nitrogen for soybean nutrition. Pre-sowing soybean seed inoculation with selected rhizobial strains is used to improve the amount of symbiotically fi xed nitrogen. Besides strain selection, suitable inoculant formulation is important for the success of inoculant application. T...