Efficient multiple shoot organogenesis in the African bush apple

Abstract African bush apple [ Heinsia crinita (Afzel.) G. Taylor] is a threatened orphan crop with immense nutritional and medicinal value to many rural African communities. We developed an efficient system for the in vitro induction of direct multiple shoot organogenesis from different explants of the crop using combinations of two cytokinins (benzyl adenine - BA and thidiazuron - TDZ) and the auxin, naphthalene acetic acid (NAA) in Murashige and Skoog (MS) medium. Multiple shoot induction was most effectively achieved from hypocotyl and stem explants using 1.0 mg/L BA + 0.1 mg/L NAA combination. In vitro -regenerated shoots were successfully rooted on hormone-free 0.5x MS medium and acclimatized to generate H . crinita plantlets, thus providing a strategy for in vitro conservation of this crop as well as a pathway for its genetic improvement via biotechnology.