Intergeneric somatic hybrid plantlets between Dianthus barbatus and Gypsophila paniculata obtained by electrofusion

Ginsenoside Rb1 in asymmetric somatic hybrid calli of Daucus carota with Panax quinquefolius

American ginseng (Panax quinquefolius L.) is one of the most valuable herbs in the world. Its major active components are ginsenosides. In order to produce ginsenoside heterogeneously, somatic hybridization, a novel approach for genetic introgression, was employed in this study. Protoplasts derived from respective calli of carrot (Daucus carota var. sativus Hoffm.) and American ginseng (P. quinquefolius L.) were used as the fusion partners. Hybrid calli derived from single cell lines containing chromatin of American ginseng were confirmed by the analyses of isozyme, Random amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH). High performance liquid chromatography (HPLC) results showed that the ginseng monomer Rb(1) was synthesized in seven of the hybrid calli identified as well as in the parent American ginseng calli but not in the parent carrot calli. Results indicated that hybrid introgression lines could produce ginsenoside Rb(1) and the ginsenoside Rb(1) biosynthesis pathway has been introgressed into carrot cells via somatic hybridization. From the point of biosafety view concerning the consumer acceptance, the potential predominance to produce ginsenosides with somatic hybridization other than with genetic transformation is discussed.

Plant regeneration from cell suspension-derived protoplasts of Primula malacoides and Primula obconica

Protoplasts were isolated from cell suspension cultures of Primula malacoides cv. 'Lovely Tokyo' and P. obconica cv. 'Aalsmeer Giant White'. P. obconica protoplasts were embedded in 0.1% (w/v) gellan gum-solidified discs comprising MS medium supplemented with 3 mg/l of 2,4-D or picloram, 0.1 mg/l of zeatin, 0.2 M glucose and 0.2 M mannitol, and surrounded by a liquid medium of the same composition except for the addition of 0.1% (w/v) activated charcoal. The protoplasts formed visible colonies, which were transferred to the regeneration medium containing 30 g/l of sucrose, 0.1 mg/l of picloram and 2 mg/l of zeatin for shoot induction. P. malacoides protoplasts formed visible colonies when cultured in disc culture using 0.1% (w/v) gellan gum-solidified MS medium containing 5 mg/l of 2,4-D, 1 mg/l of NAA, 0.1 mg/l of zeatin and 0.4 M glucose. Small calli were transferred to MS medium supplemented with 5 mg/l of zeatin for shoot regeneration. The shoots of both species readily rooted on plant growth regulator-free 1/2 MS medium and successfully acclimatized to greenhouse conditions. The protoplast-derived plants showed some alterations in morphological characteristics from those of the in-vitro-germinated control plants.