Vegetative rescue, in vitro establishment and cutting technique of Drimys brasiliensis Miers

ABSTRACT

Drimys brasiliensis Miers, popularly known as cataia, is a tree species native to the Atlantic Forest that has phytochemical, phytotherapeutic, aromatic and economic importance, with wide use in folk medicine. It is considered a species of difficult multiplication via seeds, presenting dormancy due to embryonic immaturity. Thus, the objective of this study was to analyze the vegetative rescue, in vitro establishment and propagation by way of cuttings of Drimys brasiliensis. For the rescue, the girdling techniques were applied at 30 and 90 cm from the ground, semi-girdling at 30 cm from the ground and pruned branches conditioned vertically and horizontally, being evaluated the shoot emission capacity. With the shoots obtained by vegetative rescue, the explants used for in vitro establishment were made, evaluating different immersion times in sodium hypochlorite 1.0 % (v/v) (0, 10, 15 and 20 minutes). The percentages of total, bacterial, fungal contamination and phenolic oxidation were evaluated. On the cuttings, shoots from vegetative rescue, from the aerial part of an adult individual and from detached branches were tested and placed in a mini-tunnel. The percentage of cuttings survival, percentage of cuttings with callus and percentage of rooting were evaluated. Regarding the vegetative rescue, the technique of pruned branches resulted in the induction of shoots, highlighting the branches conditioned vertically (100%). In the in vitro establishment, the immersion in sodium hypochlorite (1%) for 20 minutes proved to be efficient in the control of fungal contamination, however, no significant differences were observed in relation to the control of bacterial contamination. In cuttings, the use of cuttings from pruned branches or girdling/semi-girdling showed potential for these techniques in the cloning of the species, obtaining results close to 10% rooting. In general, the species has the potential for vegetative propagation, however, adjustments are necessary in the in vitro establishment and cutting protocols.

Keywords
Vegetative propagation; Rejuvenation; in vitro cultivation; Native species