Mini-cutting technique for Khaya anthotheca: selection of suitable IBA concentration and nutrient solution for its vegetative propagation

Khaya anthotheca is a hardwood species from Africa and recently introduced to Brazil. This species yields high-quality wood for diverse applications, but little has been done toward an effective propagation method for large-scale production in nurseries. We evaluated the effects of different concentrations of macro and micronutrients (i.e., 100, 50 and 25% of the concentration of a referenced solution) combined with indole-3-butyric acid (IBA) at 0 and 2 g L-1 on the survival rate of mini-stumps and the survival and adventitious rooting of K. anthotheca mini-cuttings. The mini-stumps were grown from a source of seeds imported from Ghana, West Africa. The mini-stumps survived at a high rate (97%). Consistently high shoot yields were obtained from the mini-stumps (average of 1.8 per mini-stump). High survival percentage of mini-cuttings and adventitious rooting were observed when solutions with 100 and 50% of the nutrients concentration were combined with 2 g L-1 IBA. Histological sections analyzed through optical microscopy indicated the tissues from mini-cutting stems were juvenile, which might have stimulated adventitious rooting. These results have important implications for further work aimed at establishing propagation strategies for K. anthotheca, which are of prime importance for assisting breeding programs of this species.