In vitro propagation of Arid zone tree species (Acacia nilotica and Acacia senegal) in Maiduguri, Nigeria

Trees are important for various reasons in the arid environment, the arid environments have less diversity and abundance of tree species. In reforesting arid environment for their various ecosystemic roles, conventional methods of propagation have been found to be inadequate. Hence there is need for thein vitrogrowth of plant species found in Arid zone to ameliorate the problem. The objective was to evaluate the effects of growth regulators Benzyl Adenine (BA) and Naphthalene Acetic Acid (NAA) and determine the potentials for regenerating plants (in vitro) and having superior genetic traits such as highquality need, disease free planting materials and tolerance to environment of the arid zone tree species. The cotyledonary node explants were exercised from the juvenile (0.5-1cm) explants and inoculated on Murashige and Skoog medium, enhanced with various concentration of BA (1.0-5.0mg/L-1) singly and in combination with NAA (0.5-2.5 mg/L-1) for the Acacia species mentioned above. The rateat which cotyledonary nodes regenerate shoot was influenced by diffrentratio of BA and NAA. Acacia nilotica produced the most shoot (1.77 ± 0.27) from medium concentration BA (1.0 mg/L-1) plus NAA (0.1 mg/L-1) for Acacia nilotica, (1.44 ± 0.41) was obtained from BA (3.0 mg/L-1) mix with NAA (0.3 mg/L-1) Acacia senegal and (1.33 ± 1.09) were obtained from BA (5.0 mg/L-1). After four weeks on the rooting medium, the plantlet failed to induce root. Result from histological study, revealed that plantlets exhibited fairly similar anatomical structures and normal organisation of epidermis, cortex and vascular bundles and also the pericycle did not show any sign of rooting. Given that callusing developed at the explants bases, this could be the cause of the unsuccessful rooting. It is recommended that further research is required to understand more about the biochemical and anatomical factors of these species to further improve both shooting and the rooting success.