African Journal of Biotechnology Vol. 3 (3), pp. 174-178, March 2004

ISSN 1684–5315 © 2004 Academic Journals

Full Length Research Paper

Screening cowpea [Vigna unguiculata (L.) Walp.] varieties by inducing water deficit and RAPD analyses

François Abaye Badiane^1,2, Diaga Diouf^1*, Djibril Sané¹, Omar Diouf², Venceslas Goudiaby³ and Nicolas Diallo^1,2

¹Laboratoire de Biotechnologies végétales, Département de Biologie Végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, BP 5005, Dakar, Sénégal.

²Centre d’Etude Régionale pour l’Amélioration de l’Adaptation à la Sécheresse (CERAAS), Thiés Escale, Route de Khombole, BP 3320, Sénégal.

3Laboratoire d'Ecologie Végétale, Institut de Recherche pour le Developpement (IRD), 

BP 1386, Dakar, Sénégal.

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

Accepted 22 December 2003

The effects of water deficit induced by polyethylene glycol-6000 on some cowpea varieties, which belong to the national germplasm in Senegal are reported. Our results showed that, the length of the epicotyl was not affected by water deficit but the length of primary root was influenced only in Mouride variety. Water deficit influenced mostly the number of lateral roots. The 985 variety showed a great increase of its lateral root numbers and could be considered a drought tolerant variety. In contrast, the IT81D-1137 variety is very sensitive to water deficit because its lateral root number were reduced 3.8 fold compared to the control. These physiological studies were complemented by analyzing the genetic diversity of these varieties with random amplified polymorphic DNA (RAPD). The RAPD analysis suggested that the samples were also genetically diverse.

Key words: Vigna unguiculata, drought tolerance, PEG, RAPD.