High-frequency embryogenesis and regeneration of plants with high content of gentiopicroside from the Chinese medicinal plant Gentiana straminea Maxim.

Gentiana straminea Maxim. (MahuaQinjiao) is an important Chinese medicinal herb that is rich in secoiridoids. To increase the production of this plant, we have developed an efficient tissue culture system for high-frequency plant regeneration. We have also obtained plants with high secoiridoid monomer production through tissue culture and somatic embryogenesis. We have found that the MB medium is better than the B5 medium for callus induction. Calluses induced from immature seeds are superior to those from hypocotyls or young leaves in regeneration via somatic embryogenesis. We have also demonstrated that 2,4-dichlorophenoxyacetic acid is efficient for both callus induction and embryogenesis, indole-3-acetic acid is suitable for embryogenic callus proliferation, and N (6)-(benzyl)-adenine promotes both embryo development and the accumulation of gentiopicroside in the cultures. Regenerated plants have been selected for high gentiopicroside content. One plant contains 5.82% of gentiopicroside, which is higher than the control plants (1.20-3.73%). The regenerated plants are genetically more stable than the calluses based on both cytological and random amplified polymorphic DNA analyses.