Root culturing ofFaidherbia=Acacia albida as a source of explants for shoot regeneration

Root culture ofFaidherbia=Acacia albida (Del.) A. Chev. can be maintained over several months by successively subculturing excised roots in modified Bonner and Devirian medium, which was found to be the best of the three media compositions tested. Adding auxins had an inhibiting effect on root growth characteristics. Mesoinositol at 0.05 mM slightly enhanced the overall elongation rate, and sucrose at 59 mM significantly increased root elongation. The effect of sucrose could not be replaced by glucose. Subcultured roots showed progressively less elongation in successive transfers. Shoots were regenerated in vitro from root segments beginning with the first passage on 1/5 strength MS medium.The large variability in the root elongation rate indicates that this technique provides an effective way to select clones with good potential for tap root growth.