Potential Nitrogen-Fixing Endophytic Bacteria in Hydroponically Grown Sweet Potato with Low Nitrogen Fertilization Revealed by 16S rRNA Gene Amplicon Sequencing

Sweet potatoes were cultivated in hydroponics with low nitrogen fertilization. Through 16S rRNA gene amplicon sequencing, the most abundant genera in storage roots of them were identified as Azospirillum, Sphingomonas, Burkholderia, Bradyrhizobium, and Arthrobacter, all of which have been reported as nitrogen-fixing bacteria. These results suggest that nitrogen-fixing bacteria may selectively increase to compensate for the insufficient nitrogen fertilization.