16S Next Generation Sequencing Analysis of Bambara Groundnut Rhizobacteria at Different Growth Stages

Bambara groundnut is one of the neglected and underutilized crops (NUS) commonly found in Sub-Saharan Africa and commonly known as a complete food. Several studies have been carried out on the nutritional properties of bambara groundnut but very little is known about the changes that occur between the microbial communities of the rhizosphere of the root at different growth stages of the plant and the bulk soil. This study reports on the bacterial communities at the different growth stages of bambara groundnut and the bulk soil. Paired end illumina-Miseq sequencing of 16S rRNA was carried on the soil samples of the bacterial community with the phyla dominated by Actinobacter (30.1%), Proteobacter (22%), Acidobacter (20.9%), Bacteroides (8.4%), Chloroflex (4.5%) and Firmicutes (4.4%) in all the soil samples. Samples from the bulk soil had the least average percent phyla (O1 and O4) while samples at 16 WAP (F1 and F4) had the highest average percent phyla. The alpha diversity at p=0.05 was highest at F1 and F4 (which corresponds to the seed maturity stage) compared to the others and the control. Rubrobacter was the most predominant genera, after which is Acidobacterium and Skermanella. It was observed from the analysis of operational taxonomic units that there was significant change in the bacterial structure of the rhizosphere with a higher abundance of potential plant growth promoting rhizobacteria, at the different growth stages which includes the genera Bacillus and Acidobacterium. These results demonstrate that the bacterial communities of bambara groundnut rhizosphere in the field are dynamic and changes with abundance of the bacterial communities at growth stages of the plant. This also implies increase in soil fertility at growth stages