Metagenomic analysis of rhizospheric soil microbial communities associated with Striga infested maize field

MSc (Biology), North-West University, Mahikeng Campus

The most problematic weed in sub-Saharan Africa (SSA), often known as witchweed, is an obligate root hemiparasite of grasses that significantly reduces and severely damages food crops. In this study, the structure and functional diversity of the microbial communities in the Striga hermonthica-infested maize rhizosphere were compared to those in unaffected soil. We hypothesize that microbial structure and diversity are influenced by Striga infestations. To evaluate the microbial diversity in the soil and the availability of biocontrol organisms in the infested soil using shotgun sequencing in this study, we compared soil samples from Striga-infested soil with those from bulk soil. The major bacteria phyla observed in all samples were Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Acidobacteria, Chloroflexi, Verrucomicrobia, and Cyanobacteria. The archaea phyla were Crenarchaeota and Euryarchaeota and the predominant phyla of fungi included Ascomycota and unclassified Fungi. The alpha diversity analysis showed that there was no significant difference in the abundance of microbiomes between infested and uninfected soil, while the beta diversity analysis showed a significant difference at p > 0.05. Additionally, the major nutrient pathways relating to plant growth-promotion properties that were identified were those involving carbohydrates, phosphorus, nitrogen, and secondary metabolism. There have also been notable traces of functional categories present in the maize rhizosphere despite the invasion of this parasite. For the biological management of Striga for sustainable agriculture, mapping out strategies to isolate novel biocontrol agents and exploring genes that can be used to effectively control this weed will be helpful.

Masters