Conservation of Hypericum foliosum Aiton, an endemic Azorean species, by micropropagation

One of the first Azorean endemic vascular taxa chosen for the development of in vitro multiplication techniques was Hypericum foliosum Aiton, due to its colonizing ability (Sjogren, 1984), a loss of seed germinatio, capacity after only 1 yr of storage (Maciel, 1994), and the populations' generally low number of individuals. The following culture media were tested using Hypericum foliosum's single node cuttings: Murashige and Skoog (1962), Roest and Bockelmman (1973), Lloyd and McCown (1980), Corte and Mendonca (1985), and Cellarova et al. (1992). Further experiments were performed on CM medium supplemented with four different growth regulators: α-naphthaleneacetic acid (NAA), N6-benzyladenine (BA), γ,γ(dimethylallyl) aminopurine (2iP), and kinetin (KIN). The acclimatization stage was carried out in Jiffy 7® pots and in a 2:1 or 1:1 peat/perlite mixture. We found that micropropagation of Hypericum foliosum is possible on CM medium and that the best results with growth regulators were achieved with the following supplements: 0.1 mg/l (0.4 μM) BA and 0.5 mg/l (2.6 μM) NAA + 1.0 mg/l (4.4 μM) BA (in the initiation stage), and 0.1 mg/l (0.4 μM) BA (in the elongation stage). As for culture multiplication, 0.1 mg/l (0.4 μM) BA (in the initiation stage) and 0.5 mg/l (2.6 μM) NAA + 1.0 mg/l (4.4 μM) BA (both in the initiation and elongation stages), proved to be the most efficient concentrations. The acclimatization stage was successfully performed in Jiffy 7® pellets.