Micropropagation from Juvenile Material of <i>Annona senegalensis</i> Pers.

Abstract

Annona senegalensis is a savannah species present in the wild in tropical and sub-tropical African regions. It is used by the local populations for its many economic, pharmacological, nutritional and ecological interests. However, the strong pressure exerted on this species as well as the increasing degradation of the ecosystems, in which it evolves, seriously compromise its sustainability and development. Conventional methods of vegetative propagation are not sufficient to ensure its durable regeneration and the renewal of endemic populations in Senegal. In this context, it was undertaken in vitro propagation, from 30 days old juvenile seedlings. Thus, axillary, cotyledonary and apical nodes were in vitro cultured in Murashige and Skoog (1962) medium (MS), with different concentrations of cytokinins and/or auxins. BAP used alone at 2 mg•L−1 proved to be more beneficial for micropropagation of different types of explants compared to Kinetin used alone or in combination with BAP, especially for axillary and cotyledonary nodes. The BAP-NAA combination allowed to have a better elongation of newly formed shoots. For shoots of apical and cotyledonary nodes origin, a rhizogenic induction of 5 days, with IBA at 25 mg•L−1, resulted in a better rooting rate with, respectively, 75% (for 2.22 roots) and 66.67% (for 4.17 roots). For newly formed shoots of axillary origin, a 24-hour rooting induction with IBA at 50 mg•L−1 gave a rooting rate of 58.33% (for 2.4 roots). After 30 days of acclimatization, the survival rate was 75% for the young plants from the apices and 83.33% for those originating from the cotyledonary and axillary nodes. This protocol can therefore be adopted for the in vitro clonal propagation of A. senegalensis juvenile material.