Exploring the genetic diversity of groundnut-nodulating rhizobia in moist and dry savannas of Nigeria for increased symbiotic nitrogen fixation and productivity

My PhD study aims at exploring the genetic diversity of groundnut-nodulating rhizobia and identifying promising strains for inoculant production to benefit the farmers and all stakeholders in groundnut production and utilization. I enrolled for the programme in the Centre for Rhizobium Studies (CRS), Murdoch University, Perth, Western Australia in February, 2013. Thereafter I prepared my programme of study on the above topic and sampled groundnut root nodules and soils from Nigerian groundnut farmers’ fields in July/August, 2013. I have conducted glasshouse experiments to establish successful growth of SAMNUT 24 and SAMNUT 22; groundnut varieties bred at the Institute for Agricultural research (IAR), Ahmadu Bello University, Zaria, Nigeria. I have also conducted experiments to screen the effectiveness of five reference groundnut - nodulating rhizobia strains, four Bradyrhizobium spp.; NC92 (The Australian commercial strain), 32H1 and AM01 from Brazil, CB756 from Zimbabwe and NGR234 (Sinorhizobium fredii) from New Guinea on the two varieties. Twenty two strains of Nigerian groundnut-nodulating rhizobia have been isolated so far, and more are in the pipeline. The next glasshouse experiments are aimed at testing the effectiveness of selected Nigerian groundnut-nodulating rhizobia strains on the same groundnut varieties with a view to identifying highly effective isolates for use in field experiments at the IAR field stations at Samaru (moist) and Minjibir (dry) Savannas in Nigeria during the next rainy season (2014/2015). Figures 1 and 2 shows the compatibility of SAMNUT 22 and SAMNUT 24 with NC92; which will be used as basis to determine the effectiveness of the Nigerian isolates in the experiments.

Aliyu Anchau, Abdullahi