Multiplication and in vitro rooting of Handroanthus impetiginosus (Mart. Ex DC.) Mattos

Multiplicação e enraizamento in vitro de Handroanthus impetiginosus (Mart. Ex DC.) Mattos

Abstract

This study aimed to evaluate cytokinin influence during in vitro multiplication stage and activated charcoal in combination with indole-3-butyric acid (IBA) during in vitro rooting of Handroanthus impetiginosus. For in vitro multiplication, nodal segments of shoots obtained from in vitro seedlings establishment were inoculated in Woody Plant Medium (WPM), with and without the following concentrations of 6-benzylaminopurine (BAP), kinetin (KIN) and thidiazuron (TDZ): 0.5; 1.0; 2.0; 4.0 and 8.0 µmol L^-1. For in vitro rooting, shoots were inoculated in WPM containing combinations among IBA (1.0; 3.0; 6.0 and 9.0 μmol L^-1) and activated charcoal (1.0; 2.0 and 3.0 g L^-1), as well as their absence within culture medium. The highest number of shoots and buds was reached after using TDZ 8.0 μmol L^-1, where in the best rooting occurred after adding activated charcoal 2.0 g L^-1, regardless of IBA concentration. Our results show that using TDZ in a suitable level for in vitro multiplication stage followed by using 2.0 g L^-1 of activated charcoal to obtain well rooted shoots is efficient for ipê-roxo micropropagation in a low cost-manner and quickly, besides providing knowledge about how to keep this threatened extinction species in an in vitro environment, which may help other conservation studies.

Keywords:
In vitro propagation; Woody plant; Plant tissue culture; Ipê-roxo