Multiplication végétative in vitro par culture d'apex chez les caféiers Coffea arabica L.; etude de l'enracinement et du transfert en pots des jeunes pousses obtenues in vitro

The effects of two auxins (IBA and NAA) on the rooting of young leaved shoots obtained by in vitro apex culture of Coffea arabica L. was studies in two phases: Firstly, different concentrations of these auxins were mixed into the culture media. The IBA + NAA combination proved to be more effective on rooting than either of the auxins used alone. Secondly, the young shoots were given inductive pre-treatment with highly concentrated aqueous solutions of IBA and NAA. Pre-soaking the leaved shoots in a solution of NAA (50 mg 1-l) for 12 hrs gave the best rhizogenesis results. Direct rooting on horticultural substrate is possible. This tends to simplify the micropropagation process since cutting out the in vitro rooting phase reduces handling and results in considerable time saving. Provided a few precautions are taken, potting the rooted plantlets has been found to be easy. Regrowth can be observed after three-four weeks. As new pairs of leaves appear, the miniature appearance of the plantlets (tiny leaves, very thin stems), which is prevalent in vitro, gradually disappears