Abstract

Plant-associated Pseudomonas live as saprophytes and parasites on plant surfaces and inside plant tissues. Many plant-associated Pseudomonas promote plant growth by suppressing pathogenic micro-organisms, synthesizing growth-stimulating plant hormones, and promoting increased plant disease resistance. This study was conducted to isolate and identify a Pseudomonas bacterium from a maize field and a free-living bacterium, Acrobeles complexus, in North West, South Africa. Therefore, this molecular study was conducted in 2017 at the North West University to identify the bacterium associated with nematode and maize filed from South Africa's soils using 16S rDNA marker. The DNA was extracted using the chelex method. The bacterium was identified as Pseudomonas fragi. Afterward, 16S rDNA was amplified using specific primers to identify the nematode. The Nblast analysis showed South African P. fragi has 96% similarity with a strain from Italy (MG972899). Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as P. fragi in the same clade with highly supported (100) bootstrap values. In conclusion, this species is identified using 16S rDNA however, using other DNA markers for a better understanding of P. fragi phylogeny is recommended.