Proceedings Volume 2010 (format .pdf) - SimpBTH

In vitro seed germination and development of seedlings. Seeds germinated in alltested media. Germination started on the 7 th day of cultivation and lasted until the40 th day reaching from 37.5 % to 97.0 % depending on media composition (Table3). Culture media G3 and G4 containing gibberellic acid in high concentrations (50mg/l or 100 mg/l, respectively) were the most efficient with 91.11 % and 93.0 % onthe 20 th day and 95.5 % and 97.0 % on the 40 th day, respectively. Seedling size onthe 20 th day varied between 14 mm (G3 medium) and 20 mm (G2 medium). Thissize was appropriate to obtain explants (apical buds and stem cuttings) forpropagation on Z-5 medium.Table 3. In vitro seed germination and development of Rodiola roseaNutrition CultivatedSeed developmentmedium seeds on the 20 th dayon the 40 th dayvariant [number] Germination [%] Seedling size [mm] Germination [%]G0 80 35.00 17.0 ± 0.09 37.5G1 100 53.00 15.0 ± 0.08 66.0G2 100 66.00 20.0 ± 0.06 72.0G3 90 91.11 14.0 ± 0.06 95.5G4 100 93.00 19.0 ± 0.07 97.0Micropropagation of Rhodiola rosea from seedlings. Seedlings developed invitro were cut to obtain apical buds and stem segments (Fig. 1) for propagation onZ-5 medium. The latter was chosen having in mind the effectiveness of zeatin inour previous experiments (Tasheva and Kosturkova, 2010). On this mediumpropagation rate of the both types of explants was not very significant.Stem segment with a leaves node formed 78 % new shoots while apical buds -75 %. The mean number of shoots per explant was 2.19 ± 0.16 and 2.00 ± 0.12 forthe first and for the second type of explants, respectively. The shoot size wassimilar – 15.1 ± 0.11 mm and 14 ± 0.47 mm (on 15 th days). The coefficient ofpropagation varied during the different seasons. Highest level of proliferation wasobserved in May-June, when the number of shoots per stem explant was 6.78 ±0.10.During cold seasons (October-March) multiplication was relatively lower - 2.11± 0.07 shoots per explant.Fig 1. Explants from in vitro plants Rhodiola rosea.Further, in our experiments, the effect of phytoregulators onthe processes of propagation and rooting of regenerants obtained107