Enraizamiento in vitro y ex vitro de microtallos de Ugni molinae Turcz., una especie nativa de Chile/In vitro and ex vitro rooting of Ugni molinae Turcz. microshoots, a native species to Chile

Two trials were established to evaluate the in vitro and ex vitro rooting of selected microshoots of two selected clones of Ugni molinae. In the in vitro experiment, nine treatments were compared, combination of three concentrations of Murashige and Skoog medium (MS) (1, ½ and ¼ strength macronutrients) and three concentration of indole 3-butyric acid (IBA, at 0, 1 and 2 µM). In the ex vitro assay we established for IBA four concentrations (0; 4.9; 9.8 and 19.7 mM). After 30 days total survival, rooting percentage, root length and number of roots per explants were evaluated. Both clones responded differently to the treatments used. Under in vitro conditions, Clone 1 had an average of 97% rooting at ½ MS + 1 µM IBA, whereas Clone 2 obtained a 93% of rooting with ¼ MS + 2 µM IBA. Our results indicate that the decrease in the strength of MS medium and the addition of IBA promotes rooting. With regard to ex vitro conditions, the Clone 1 did not respond to IBA applications, while in Clone 2, IBA promoted the rooting at the concentration of 19.7 mM, with percentages of 90 and 85%, respectively. Considering these results, it is generally recommended to use the ex vitro rooting system because both clones were able to obtain the same high percentage rooting (above 85%) in this system. Ex vitro propagation will also safe costs.