Full Length Research Paper

In vitro plantlets regeneration in Bambara groundnut [Vigna subterranea (L.) Verdc. (Fabaceae)] through direct shoot bud differentiation on hypocotyl and epicotyl cuttings

Koné Mongomaké¹, Kouakou Tanoh Hilaire¹, Koné Daouda², Zouzou Michel², Kouadio Yatty Justin¹ and Sergio J. Ochatt³

¹Université d’Abobo-Adjamé, UFR des Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions végétales, 02 B.P. 801, Abidjan 02, Côte d’Ivoire.

²Université de Cocody Abidjan, UFR Biosciences, Laboratoire de Physiologie et Pathologie Végétales, 22 B.P. 582 Abidjan 22, Côte d’Ivoire.

³INRA, C.R. de Dijon, UMRLEG 0102, PCMV, B.P. 86510, F-21065 Dijon Cedex, France.

*Corresponding author. E-mail: mongokone@yahoo.fr. Tel : (225) 20 30 42 66 / 20 30 42 00. Fax : (225) 20 30 81 18. Télex: Rectu-CI ABIDJAN.

Abbreviations: BAP, 6-Benzylaminopurine; Kin, 6-furfurylaminopurine; TDZ, N-phenyl-N-1,2,3-thidiazol-5yl-urea; NAA,  α- naphthaleneacetic acid; IBA, indole-3-butyric acid.

Accepted 8 January, 2009

In vitro regeneration system via direct organogenesis in Bambara groundnut (Vigna subterranea L.) using hypocotyl and epicotyl cuttings was studied. Basal Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP), 6-furfurylaminopurine (kinetin) or Thidiazuron (TDZ) with or without α-naphthaleneacetic acid (NAA) were attempted. Multiple shoots were induced from both explants but regeneration efficiency was higher when epicotyl cuttings were used. The ability of hypocotyl and epicotyl cuttings to produce shoots varied depending on the culture medium. BAP (2 mg/l) gave the highest response (73.33 - 97.77%) with the regeneration of 3.7 shoots per explant with hypocotyl and 5.8 shoots per explant with epicotyl. Substitution of BAP at an equimolar concentration with kinetin and TDZ, and incorporation of NAA during shoot bud induction did not show any improvement over that obtained with BAP and promoted callusing to a different degree. The regenerated shoots were readily elongated on the same medium as used for induction and rooted on half-strength MS basal medium without any growth regulators. 62% of the plantlets were successfully acclimatized and potted plants were established in soil with 73% survival rate.

Key words: Vigna subterranea, hypocotyl and epicotyl cuttings, shoot organogenesis, plant regeneration, explant orientation.