Isolation of Rhizobia From the Nodules of Bambara Groundnuts for Inoculant Production

Abstract

Rhizobia symbiotic interactions with legumes fix atmospheric nitrogen into the soil, which is essential in amending the characteristically low-nitrogen soils in most farming communities in northern Ghana. A high potential for improvement of Bambara groundnuts production in low-nitrogen soils is by the exploitation of colonization of the plant roots with rhizobial inoculation. This experiment sought to isolate Legume Nodulating Bacteria (LNB) obtained from root nodules of Bambara groundnut (Vigna subterranea) plants and to identify effective strains for improved production of the crop. Roots nodules of Bambara plants used in this study were obtained from preserved plants and the isolates were authenticated for their symbiotic effectiveness under screen house conditions. Nodulation of the isolates was examined in plastic pots containing sterile river sand and test crop (Bambara seeds). The experiment included reference strains, a positive nitrogen control and an un-inoculated control. The results were obtained after two months of data collection. The difference in results was explained via nodulation capacity. Out of the two isolates obtained, 2CL showed a high nodulation capability, rating it as highly effective. The outcome of this study provides stakeholders with the prospect for the use of effective isolates as inoculants to improve Bambara groundnut yield in general and in northern Ghana in particular.