Somatic embryogenesis and plant regeneration from cell suspensions of Exacum affine

Abstract

Somatic embryos were produced in seven cultivars of Exacum affine Balf. using flower buds and peduncles as explants. Flowering plants were produced from five of the cultivars, and no visible mutations were detected. The best medium for callus induction and growth was MS supplemented with 9.0 ~M 2,4-dichlorophenoxyacetic acid and either zero or 0.089 I~M BA. Callus suspensions were made by passing the callus through a 100 I~m sieve. The best embryo regeneration was achieved on growth regulator-free medium. Callus and embryos could be grown in liquid medium.

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

“…We have also found that 13.57 μM 2,4-D was the most effective for promoting somatic embryogenesis among the different concentrations of 2,4-D, NAA, and IAA tested. Similar results were reported on gentian somatic embryogenesis (Ørnstrup et al 1993;Tabira 1994). It is known that auxins (such as 2,4-D) are efficient for inducing cell division, while hormone-free medium or cytokinins (such as KT or BA) promotes development of embryos.…”

“…It is known that auxins (such as 2,4-D) are efficient for inducing cell division, while hormone-free medium or cytokinins (such as KT or BA) promotes development of embryos. 2,4-D and KT have been found to be efficient for the formation of embryos, and 2,4-D by itself is sufficient to initiate cell division and embryonic development up to the cotyledon stage (Ørnstrup et al 1993;Tabira 1994). In our research, we noted that auxin (2,4-D) in combination with cytokinin (KT) decreased the frequency of induction of G. straminea embryos.…”

Somatic embryogenesis of Gentiana genus I. The effect of the preculture treatment and primary explant origin on somatic embryogenesis of Gentiana cruciata (L.), G. pannonica (Scop.), and G. tibetica (King)

“…The intensity of G. pannonica root-derived culture proliferation developed in the dark was comparable to effectiveness of callus formation of cotyledon (in the dark) of G. pannonica, but hypocotyl and cotyledon (both in the dark) of G. tibetica. In all already published papers on gentiana somatic embryogenesis, medium manipulation consisted of the explant tissue treatment by auxin (2,4-D) to induce cell division, followed by the transfer of proliferating tissue to hormone free medium to develop embryo (Ornstrup et al 1993, Tariba 1994. Contrary to these results our cultures regenerated embryogenic callus on the same medium (2,4-D and Kin) that formed embryos.…”

Phytochemistry and Biotechnology Approaches of the Genus Exacum

“…Development of somatic embryos was observed only on a medium lacking 2,4-D, or with the addition of less than 9.0 µM 2,4-D (Ornstrup et al 1993).…”

“…The young parts of plants are the least contaminated microbiologically. The species E. affine is also known for endogenous bacterial infections, and which is why buds and pedicels were used as explants in the study by Ornstrup (1993). Explants were taken from seven varieties of E. affine.…”