Influence of different macronutrient solutions and growth regulators on micropropagation of juvenile Acacia mangium and Paraserianthes falcataria explants

The influence of rive different macronutrient formulations and various growth regulators on micropropagation of single node explants from #Acacia mangium# and #Paraserianthes falcataria# seedlings was examined after 4 weeks and 8 weeks #in vitro#. The experiment was repeated 4 months later. On media lacking growth regulators, growth and development were significantly influenced by the different macronutrient solutions tested, although morphogenic responses could vary according to the species. For instance, #P falcataria# displayed a greater ability for adventitious rooting than #A. mangium#. Overall, Knop macronutrient solution induced the weakest responses. Explant responsiveness was significantly influenced by the addition of 2.2 or 4.4 µM 6-benzyladenine combined with either 1,4 or 2.3 µM kinetin, 1.5 or 2.5 µM indolebutyric acid or 1.6 or 2.7 µM naphthaleneacetic acid. Trie various combinations of growth regulators tested were shown to inhibit the rooting ability of the explants, while stimulating the production of basal shoots for both species, and of axillary shoots only for #A. mangium#. In such experimental conditions, #A. mangium# displayed overall a greater potential for micropropagation than #P falcataria#. (Résumé d'auteur