M. Doi, S. Hamatani, T. Hirata, H. Imanishi, T. Hisamoto
Clumps of shoot primordia were formed on the basal shoot sections of etiolated Freesia sprouts cultured in liquid Murashige and Skoog (MS) medium supplemented with 1ppm NAA or 1ppm 2,4-D and 1ppm BA. These shoot primordia were subcultured under dark condition in modified MS liquid medium with 1/10 strength NH4NO3 and 1ppm BA. The proliferation rate of shoot primordia was 1.5 per month and was retained in successive subcultures using this liquid medium.

Efficient shoot regeneration was obtained when the primordia were cultured on modified MS agar medium with 1/10 strength NH4NO3 and 1ppm BA under 16 hr daylength.

When the regenerated shoots were transplanted on hormone free medium and cultured under 16 hr daylength and 0.1% CO2 enriched conditions, root system developed well and shoots grew vigorously. Plantlets cultured under CO2 enriched conditions were easily acclimatized to ex vitro as compared with the plantlets cultured under ambient atmospheric conditions. Consequently, one corm and three cormlets were produced per plant, indicating that more than 500 corms were obtained per year by originating from 1g shoot primordia.

Corm formation was also observed under in vitro conditions, if regenerated shoots were exposed to chilling at 15°C for 10 weeks and then moved to 23°C.

Doi, M., Hamatani, S., Hirata, T., Imanishi, H. and Hisamoto, T. (1992). MICROPROPAGATION SYSTEM OF FREESIA. Acta Hortic. 319, 249-254
DOI: 10.17660/ActaHortic.1992.319.37

Acta Horticulturae