The research about the indigenous soybean bradyrhizobia in the Philippines is scarce, and this greatly influences the improvement of soybean production in the country. Thus, soil samples were collected from 11 locations in the country and were used to isolate the indigenous bradyrhizobia in the soil. Through the use of polymerase chain reaction—restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 16S rRNA gene, 16S-23S rRNA gene internal transcribed spacer (ITS) region and rpoB housekeeping gene, the most abundant and dominant indigenous bradyrhizobia in the country were identified. Then, the representative isolates of the most dominant species per location were used to test their symbiotic efficiency and N-fixation ability with the local soybean cultivars. The results showed that among all the tested indigenous strains, the B. elkanii IS-2 is the most effective and efficient microsymbiont of the Philippines’ local soybean cultivars. This report was able to provide necessary information on the distribution of soybean bradyrhizobia in the Philippines and characterized the symbiotic performance of the indigenous strains.
Part of the book: Nitrogen Fixation