Abstract

BOHORQUEZ-QUINTERO, María A; ARAQUE-BARRERA, Eyda J  and  PACHECO-MALDONADO, José C. Propagation in vitro of Espeletia paipana S. Díaz and Pedraza, a critically endangered endemic frailejon. Actu Biol [online]. 2016, vol.38, n.104, pp.23-36. ISSN 0304-3584.  https://doi.org/10.17533/udea.acbi.v38n104a03.

In this study we established a micropropagation protocol for Espeletia paipana S. Díaz and Pedraza, a critically endangered species with a current population size of 26 adult plants. The primary explants (seeds) used were superficially disinfected with sodium or calcium hypochlorite. The aseptic embryos were cultured on MS media with macroelements at different concentrations, with and without gibberellic acid (GA₃), kinetin (KIN), and indole-3-butyric acid (IBA). The effects of temperature and light on germination also were examined. For multiplying shoots, we used MS supplemented with IBA and benzylaminopurine (BA). Shoot rooting was attempted by using IBA + BA, IBA, and 1-naphthalene acetic acid (NAA), and different mixtures of peat, mulch and sand were tested for hardening of the seedlings. The results showed that the highest percentage (66%) of aseptic embryos was obtained using 1% calcium hypochlorite. The highest percentage (50%) of germinated embryos was registered using the MS/4 supplement with 1 mg l^-1 GA₃, and the highest quantity of reactive embryos and viable seedlings were obtained at 24 °C with continual illumination. The best shoot proliferation results were achieved on MS with 0.5 mg l^-1 IBA + 0.05 mg l^-1 BA, while 85% rooting was achieved on MS with 5 mg l^-1 IBA. The highest percentage (65%) of viable seedlings in a growing house was obtained using a mixture of soil enriched with organic matter and mulch in a 3:1 proportion. The proposed protocol may be employed to develop massive propagation programs, which could reverse the trend toward extinction of E. paipana.

Keywords : Asteraceae; conservation; germination; growth regulators; micropropagation; paramos.

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