African Journal of Biotechnology Vol. 2 (2), pp. 48-50, February 2003

ISSN 1684-5315  © 2003 Academic Journals  

Genetic diversity in cowpea [Vigna unguiculata (L.) Walp.] varieties determined by ARA and RAPD techniques

Laïty Fall¹, Diaga Diouf^1*, Mame Arama Fall-Ndiaye ¹, François Abaye Badiane¹ and Mamadou Gueye²

¹Laboratoire de Biotechnologies Végétales, Département de Biologie Végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal

²Laboratoire de Microbiologie des sols ISRA-IRD, BP 1386, Dakar, Sénégal

*Corresponding author; E-mail: ddiouf@ucad.sn

Cowpea, Vigna unguiculata (L.) Walp. presents phenotypical variabilities and in order to study the genetic diversity of cultivated Senegalese varieties, two experimental approaches were used. First, a physiological characterization based on nitrogen fixation was used to assess cowpea breeding lines. Inoculation with two Bradyrhizobium strains (NGR234 and ISRA312), showed a difference in nitrogen fixation potential between the cowpea varieties. Diongoma is the highest nitrogen fixing variety, whereas Mouride is the lowest. The second approach employed genetic characterization based on DNA polymorphism to screen. Results suggest that random amplified polymorphic DNA (RAPD) technology can be used to reorganize the national germplasm in order to eliminate the putative duplicates, and to identify elite varieties.

Key words: Vigna unguiculata, nitrogen fixation, cowpea, molecular markers, RAPD.