Micropropagation of Citronella mucronata D. Don, a Vulnerable Chilean Endemic Tree Species

Citronella mucronata (C. mucronata), a tree species endemic to Chile, has become threatened in its natural habitat and is currently listed as vulnerable. Tree population parameters have deteriorated due to indiscriminate logging and other anthropogenic activities, warranting research on mass propagation as a means of recovery. This study, unprecedented for this native species, has developed a successful method for its micropropagation. The objective was to establish a protocol for in vitro propagation of C. mucronata to produce large quantities of high-quality seedlings in an accelerated plant acquisition process. The best results were achieved by growing explants on Murashige and Skoog (MS) basal culture medium supplemented with 4.44 μM 6-benzylaminopurine (BAP) and 14.76 μM indole-3-butyric acid (IBA). Explant survival rate was 78 %, the average shoot length reached 3.2 cm, the number of lateral shoots was 3.9, and rooting rate was 60%. Furthermore, stimulation with red and blue light in a 1:2 ratio, supplemented with 14.76 μM IBA, improved the rooting rate to 93%. The survival rate of rooted explants reached 100% in the acclimatization stage when using peat and perlite substrate (1:1 v/v).