An improved transformation system for cowpea (Vigna unguiculata l. Walp) via sonication and a kanamycin-geneticin selection regime

An improved cowpea transformation method utilizing Agrobacterium-mediated gene delivery to explants derived from the cotyledonary nodes of imbibed cowpea seed is described. The explants were regenerated following a sonication procedure and a stringent selection comprising alternating regimes of kanamycin and geneticin. The method was reproducible and led to the recovery of independent fertile transgenic plants in the greenhouse at a level of about one per cent of starting explants. A transgene encoding an insecticidal protein from Bacillus thuringiensis was used to demonstrate the efficacy of the system.