In vitro propagation of rare species Rhodiola rosea from Altai Mountains

The techniques of biotechnology are considered promising and highly-demanded for propagation and conservation of rare species of medicinal plants. The variety of natural forms of Rhodiola rosea makes it difficult to develop a single efficient in vitro protocol for this valuable and rare medicinal plant. The optimization of in vitro methods for specific populations to effectively mass production of planting material R. rosea is required. The paper provides the technique for in vitro propagation of R. rosea from the population of Altai Mountains, including sterilization of seeds in an aqueous solution of sodium hvpochlorite, planting of seedlings on Murashige and Skoog medium (MS) supplemented with 5 mu M 6-benzvlaminopurine (BAP) and 2.5 mu M alpha-naplithylacetic acid (NAA), rooting of microshoots on hormone-free 1/2 MS medium and acclimatization in the substrate consisting of peat and perlite at a ratio of 2 : 1. We have shown that no additional pre-sowing treatment is required for effective in vitro germination of R. rosea seeds. The seedlings of R. rosea exhibit a high germination rate and are a promising explant type for in vitro mass propagation of the plant. This technique provides a high yield of in vitro cultivated plants (6.3 plants per explant, 95-100 % rooting) and a high percentage of plant acclimatization (78 %). The average weight of roots (wet weight) during acclimatization and growth (7 months) was 12.2 +/- 2.4 g. The developed technique of in vitro propagation of R. rosea allows both to conserve the natural populations of this rare plant and to obtain planting material for commercial cultivation.