A rapid and mass propagation method for multiple shoots and plant regeneration using bulb scales of Muscari comosum var. plumosum were developed. In vitro different parts of bulb scale as explants were cultured on 11 kinds of MS (1962) media supplemented with various plant growth regulators to induce shoot and callus. A combination of 2.0 mg/L 6-BA and 2.0 mg/L IBA on MS medium was the most favorable and induced the highest production (80%) of shoot formation after 30 days. We also found that the middle part of bulb scale was the best for mass propagation of Muscari comosum var. plumosum of which production could reach 64.4%.

In vitro high-frequency plant regeneration of Muscari comosum var. plumosum through somatic embryogenesis was obtained via two developmental pathways: direct embryos and multiple shoots regenerated from embryogenic callus. Flower bud with pedicel, receptacle, petal and ovary wall, floral stalk and leaf as explants were cultured in MS medium supplemented with various plant growth regulators. Embryos formed directly from pedicel, receptacle and floral stalk. Depending on explant sources, the optimal medium was MS medium supplemented with 0.2 mg/L IBA and 0.3 mg/L BA, 3.0 mg/L IBA and 3.0 mg/L BA, and MS-free medium for pedicel, receptacle, and floral stalk, respectively. Multiple shoots regenerated from embryogenic cal]i which was initiated from petal, ovary and leaf were observed in MS medium with different concentrations and combinations of hormone. The most suitable medium for each type of explant was 3.0 mg/L IBA and 3.0 mg/L BA(petal and ovary) and 5.0 mg/L IBA and 5.0 mg/L BA (leaf) Furthermore, the combination of 0.1 mg/L 2,4-D and 1.0 mg/L BA was also good for all sources of explants not only for direct embryo formation, but also, for embryogenic callus induction.

An efficient plant regeneration system of Gentiana scabra through somatic embryogenesis was established. Leaves and roots of seedlings of Gentiana scabra excised after germination were cultured on MS basal medium with 2,4-D, NAA or BA. Embryogenic callus was obtained on MS medium with 0.5 mg/L 2,4-D alone or 0.1 mg/L 2,4-D combimation with 1.0 mg/L BA after 45 days of culture. These embryogenic calli gave rise to somatic embryos, which subsequently developed into plantlets on MS medium without PGRs. Also, shoots were effectively differentiated from embryogenic callus when root segments were cultured on MS medium supplement with 0.1 mg/L 2,4-D and 1.0 mg/L BA. Shoots were effectively rooted on MS medium without PGRs. In vitro flowers were formed from plantlets cultured on MS medium with 5% sucrose after 60 days of culture.

Transgenic Petunia hybrida cv. Rosanpion was produced by Agrobactepium tumefaciens LBA4404 harboring a binary vector pBI 121 containing β-glucuronidase (gus) and neomycin phosphotransferase (nptII). For genetic transformation, leaf discs were precultured on MS medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BA (MNB) for 2 days and cocultured for 15 mins with A. tumefaciens. For selection of transformant, leaf discs were transferred to fresh MNB containing 50 mg/L kanamycin and 500 mg/L cefotaxime. Eighteen plants were regenerated and four were confirmed by PCR for detection of gus and nptII gene integrated into the nuclear genome of petunia ‘Rosanpion’. Using this transformation system, we expect that transgenic petunia ‘Rosanpion’ incorporating a useful gene can be produced.