Adventitious root initiation in adult and juvenile cuttings of Guindilia trinervis, an endemic plant of Chile suitable for biodiesel production

Abstract

Guindilia trinervis is a native Chilean shrub that bears seeds with a high content of oil suitable for biodiesel production. It was tested for its capacity to form roots in cuttings of juvenile and adult plants in ex vitro as well as in vitro conditions. Variables such as type of cutting, exogenous application of IBA¹ and time of collection were studied. For adult plants, the best ex vitro rooting (79 %) was obtained with distal polynodal cuttings collected in late summer and treated with 100 mg L^–1 IBA, but rooting was also achieved in the presence of water alone (up to 69 %). Juvenile plants displayed the best rooting (84 %) with single node cuttings and 50 mg L^–1 IBA, as well as in the presence of Seradix (72 %). This treatment also showed the highest number of roots per explant. In vitro rooting of shoot tips took place on modified MS media supplemented with 1.0 mg L^–1 IBA yielding roots up to 82 %, compared to nodal sections that rooted scantily. Rooted material could be acclimated and adapted well to greenhouse and nursery conditions. Controls of adult and juvenile cuttings treated with water exhibited spontaneous rooting in most of the treatments. Cuttings from adult plants harvested in late summer rooted better than those harvested in winter. Spring cuttings collected during flowering and fructification did not root. Results indicate that by means of adventitious root initiation G. trinervis can be effectively propagated by distal cuttings, collected in summer or winter. This may allow large-scale production of plant material with desired traits.