Vernonia condensata Baker: an alternative for large-scale seedling production

The increasing use of Vernonia condensata Baker highlights the importance of developing strategies to reduce the impact of exploitation on nature reserves. The aim of this study was to establish a micropropagation protocol to produce homogenous plants with high phytosanitary quality. Apical, nodal, and internodal segments of plants grown in the field were used for in vitro growth. The segments were disinfected in sodium hypochlorite solution (1.0 and 2.0%) for 15 and 30 minutes and then transferred to Petri dishes containing MS culture medium for 30 days. A completely randomized factorial experiment (3 x 2 x 2) with five replicates was designed. After this period, a completely randomized in vitro multiplication experiment was carried out with six treatments (BAP - 0.0: 0.5; 1.0; 1.5: 2.0; 2.5 mg L-1) and six replicates. The shoots obtained in the best treatment were transferred to flasks with rooting medium (MS, MS/2 or MS/4). The experiment was completely randomized with 12 replicates. Microplants were acclimatized in polyethylene terephthalate (PET) bottles filled with autoclaved topsoil. Our results showed that 40.0% of the nodal segments (immersed in 1.0% sodium hypochlorite for 30 minutes) were adequately disinfected and survived. In the in vitro multiplication experiment, the 0.5 mg L-1. concentration of BAP yielded the highest number of shoots and the best vegetative growth. With regard to the assessed characteristics, MS/4 was the best rooting medium, with 100% survival during acclimatization. This study showed that V condensata in vitro culture might produce 32,000 seedlings in 7 months.