Effect of different media composition on the micropropagation of Erica andevalensis, a metal accumulator species growing in mining areas (SW Spain)

We describe a micropropagation and acclimatization protocol of Erica andevalensis Cabezudo & Rivera, using stem pieces collected from wild plants. This species always grows in soils enriched with metals such as Fe, Pb, Zn and in acid pH (2.5–4). Among the different media and hormone concentration tested, MS medium with ammonium nitrate concentration reduced to a quarter, 2 mg l⁻¹ indole-acetic acid (IAA) and 0.5 mg l⁻¹ kinetin was found to yield the best growth response in the plants. This medium produced an average of 3.6 ± 1.2 shoots and 16.9 ± 8.3 verticils per explant after 30 days of the onset of the culture. MS media achieved rooting without phytohormones. Rooted plantlets were successfully transferred to plastic containers with autoclaved perlite, watered with MS half-strength, and then to pots with commercial substrate after 2 weeks. New plants were produced in about 100 days. As far as we know, this is the first time that a replicable and complete micropropagation protocol for E. andevalensis has been developed. The plants looked healthy with no visual detectable phenotypic variations. The protocol provides a successful technique that could be used for the conservation of the species, as well as new researches on phenolics and triterpenoids compounds found in plant extracts.