| heal.abstract |
Sideritis athoa is an alpine, aromatic perennial herb, and a native plant of Greece that could be introduced as a bedding plant, a plant for rock gardens, roof gardens, restoration of degraded landscapes and to maintain slope stability. S. athoa seeds were collected in August and germinated in November in vitro or on peatperlite (1:1 v/v) or 100% perlite media. Seeds were placed onto a solid half strength MS medium with 20 g/L sucrose and held at 10, 15, 20 or 25°C either under continuous darkness or 16-h photoperiod (37.5 μmol·m-2·sec-1 fluorescent light). Germination at 20°C was high independent of substrate and light. The highest germination (80-88%) was obtained for seeds planted on peat-perlite or 100% perlite at 20°C. On MS medium germination was slightly lower and delayed. Nodal explants from in vitro grown seedlings were cultured on solid MS with 8 g/L agar and 20 g/L sucrose supplemented with various plant growth regulators (BA, 2iP, TDZ, NAA, IBA) in order to induce shoot regeneration. The highest shoot numbers were obtained in media with BA (0.2, 0.5 or 1.0 mg/L) (2.3-2.5 shoots per explant, 0.6 cm long). The addition of NAA to the BA-media reduced the production of shoots and induced callus and shoot malformation. Callus and malformations were observed in TDZ-media, while the 2iP-media gave low shoot production. The medium with 1 mg/L IBA produced fewer but longer shoots compared to BA-media (1.5 shoots per explant, 2 cm long). Nodal explants from in vitro produced shoots were initially successfully subcultured for multiplication on media with 0.2 mg/L BA with or without 0.1 mg/L IBA. However, in subsequent subcultures, many shoots were hyperhydrated. Increased agar (12 or 20 g/L) or sucrose (30 g/L) concentrations eliminated hyperhydration. Microshoots held on IBA (2 mg/L) alone or with NAA (1 mg/L) gave the best rooting in terms of percentage (46% or 53%, respectively) and root quality. |
en |