Anthocyanin production from Vaccinium pahalae: limitations of the physical microenvironment.

Physical microenvironmental parameters conducive to production of flavonoids in vitro from continuous Vaccinium pahalae suspension cultures were examined first in shake flask culture experiments, and results were used to guide adaptations of a bioreactor production environment. Anthocyanin pigments were primarily concentrated in smaller aggregates up to 519 microm diameter. Agitation at 150 rpm and routine use of a mechanical scraper to periodically retrieve cells thrown out of solution was sufficient to keep productive plant cell aggregates in bioreactor suspension. A set up for enhanced irradiance with mercury lamps providing an average of 240 micromol m(-2) s(-1) PPF at the inner surface of the bioreactor vessel was required to sustain anthocyanin productivity through a 10-day production cycle.

Plant regeneration from encapsulated somatic embryos of Carica papaya L.

Carica papaya L. (papaya) single somatic embryos (2.0 mm diameter) produced in a high-frequency liquid production system were encapsulated in two different synthetic encapsulation compounds. The frequency of regeneration from encapsulated embryos was significantly affected by (1) the concentration of sodium alginate, (2) the presence or absence of nutrient salts in the capsule, and (3) the duration of exposure to calcium chloride. A 2.5% sodium alginate concentration in a half-strength MS salts base resulted in significantly higher germination frequencies than other treatments. A relatively short (10 min) exposure to CaCl2 provided uniform encapsulation of embryos and the highest frequencies of successful germination (77.5%). Germinated artificial seeds produced normal plantlets.

Direct somatic embryogenesis fromBegonia gracilis explants.

Direct somatic embryogenesis ofBegonia gracilis was achieved from microcultured laminar segments and petioles on Murashige and Skoog medium with 0.5 mg 1-1 kinetin and 2% coconut water. Somatic embryos were obtained with greater frequency from petiole explants than from leaf blade sections. Under red light (45 µmol m-2 s-1), approximately 80% of the petiole explants successfully produced somatic embryos but only 30% of the leaf blade sections responded. However, somatic embryos were significantly more abundant on responding lamina explants (60-70 embryos/leaf section) than on petioles (40-50 embryos/petiole). These trends were similar for explants kept in the dark, but overall production was lower. Somatic embryos were produced more quickly (5 weeks) from petioles than from lamina explants (8 weeks). The somatic embryos germinated to produce plantlets and subsequently shoot cultures with the same appearance as the parental clone.