Ann Microbiol Immunol | Volume 2, Issue 2 | Research Article | Open Access

Promiscuous Symbiotic Interaction between Rhizobium and Glycine max (Soybean) in Tropical Soils Southwest Nigeria

Olusola Abayomi Ojo-Omoniyi1*, Efosa Winifred Ngbeken2 and Kehinde Samuel Adebiyi1

1Department of Microbiology, Lagos State University, Nigeria 2Department of Biological Sciences, Covenant University, Nigeria

*Correspondance to: Olusola Abayomi Ojo-Omoniyi 

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Tropical soil samples were collected from three different locations Southwest, Nigeria. The first location was Lagos State University: Faculty of Science, Faculty of Management Science and Lagos State University second gate. The second location was Covenant University: soil was collected from the College of Science and Technology, College of Developmental Studies, Lecture theatre and the Covenant University farm. The third location: soil samples were collected from Shagamu. All soil samples were collected at a depth of 0 cm to 30 cm using a hand trowel and were transported to the laboratory in sterile polythene bags. Control soil samples were obtained from Badagry beach in Lagos. The purpose of this study is to isolate native Rhizobium sp. from tropical soils southwest Nigeria with the ability to nodulate the legume Glycine max (Soya beans). Serial dilution of the soil samples following aseptic processes generated dilution factors 10-4 and 10-5 used as inocula for the pour plate method using Nutrient Agar (NA) and Yeast Extract Mannitol Agar (YEMA) as growth media. The plates were incubated at 28 ± 2°C for 48 h which made visible growth to be observed. Visible differences between the numbers of colonies of dilution factors 10-4 and 10-5 were observed on both NA and YEMA after the colonies were counted. Physical examination of the culture plates showed that all of the colonies appeared round, mucoid and 58.3% of the colonies were creamy white on YEMA. Microscopic examination revealed motile Gram–negative rods on YEMA while 50% of the isolates on NA were non-motile rods. The mean Rhizobium sp. population detected in the soil samples was 0.33 × 10-5 CFU/g. Conclusively, the presence of indigenous rhizobia population specific for Soya bean in the soils evident by nodulation of the legume 8 Week after Planting (WAP) confirms both the symbiotic relationship and its relevance to sustainable agricultural practice.


Ojo-Omoniyi OA, Ngbeken EW, Adebiyi KS. Promiscuous Symbiotic Interaction between Rhizobium and Glycine max (Soybean) in Tropical Soils Southwest Nigeria. Ann Microbiol Immunol. 2019; 2(2): 1017.

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