ISSN 2169-3048
International Journal of Biochemistry and Biotechnology ISSN 2169-3048 Vol. 15 (4), pp. 001-007, April, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals
Full Length Research Paper
Water Effects on Cowpea Rhizobia Competition and Nodule Occupancy
Tatiana Krasova-Wade1*, Omar Diouf2, Ibrahima Ndoye1, Ciré Elimane Sall3, Serge Braconnier2, and Marc Neyra1,4
1Laboratoire Commun de Microbiologie IRD/UCAD/ISRA, (LCM), Centre de Recherche de Bel Air, B. P. 1386, C.P.
18524 Dakar, Sénégal
2Centre d’Etude Régional pour l’Amélioration de l’Adaptation à la Sécheresse (CERAAS), B. P. 3320, Thiès Escale, Thies, Sénégal
3Institut Sénégalais de Recherche Agricoles (ISRA), B. P. 3120, Dakar, Sénégal
4Present address : Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), Campus de Baillarguet, TA10/J, 34398 Montpellier Cedex 5, France
Accepted 27 January, 2026
Two indigenous bradyrhizobia strains displaying different natural behaviours towards water regime (strain ORS 3257, nodulating more frequently in favourable-water conditions and strain ORS 3260, in limited-water conditions) were studied for their competitivity for nodulation of cowpea (Mouride cultivar) under favourable and limited water conditions in non-sterile soil. The nodule occupancy was studied by PCR-RFLP analysis. Both strains showed good competition with other indigenous rhizobia populations under favourable- and limited-water conditions. Competition between the inoculated strains in the mixture varied between water regimes. In non-limited-water conditions, strain ORS 3257 was the best competitor, whereas in limited-water conditions, strain ORS 3260 was the best competitor. Results indicated that screening of strains according to their environmental origin could ensure successful rhizobia inoculation.
Key words: Vigna unguiculata, bradyrhizobia, inoculation, competition, limited-water conditions.