Carnivorous plants can live in soil with low levels of mineral nutrients (Lowrie, 1998), because most species obtain a substantial nutrient supply by trapping and digesting insects and small animals. Carnivory has been documented in at least nine families and ≈500 species in the world (Lowrie, 1998). The carnivorous Venus fly trap (Dionaea muscipula Ellis), which belongs to the monotypic genus Dionaea of the Droseraceae family, is a perennial plant indigenous to bogs in coastal areas of North and South Carolina and has also been introduced in Florida (Culham and Gornall, 1994). Micropropagation allows the production of a large number of plants and is a useful tool for producing carnivorous plants and their byproducts. For example, naphthoquinones, which are traditional remedies for dry and irritating coughs, can be produced and extracted from cell suspensions and in vitro cultures of Venus fly trap (Hook, 2001). Stable in vitro plantlet regeneration of the Venus fly trap has been achieved using floral stalk explants (Teng, 1999), and an in vitro micropropagation method was established by shoot culture (Jang et al., 2003). Pinguicula lusitanica L., a rare insectivorous plant with pharmacological value and limited reproductive capacity, was also efficiently propagated in vitro (Goncalves et al., 2008). Propagation of Nepenthes khasiana Hooker, an endangered medicinal plant and the only insectivorous pitcher plant of India, was propagated through enhanced axillary branching in vitro (Latha and Seeni, 1994). Adams et al. (1979) described a method for propagation of Cephalotus follicularis by shoot tip culture and increased clonal multiplication using half-strength Linsmaier-Skoog (LS) medium (Linsmeier and Skoog, 1965).
Cephalotus is a genus of flowering plants belonging to the monotypic family Cephalotaceae. Cephalotus follicularis Labill., an attractive insectivorous plant endemic to southwestern Australia, has two leaf forms: simple lanceolate leaves and developed pitchers. The flower of C. follicularis has six ovate–elliptic sepals, 12 filaments with mauve stamens, and six pale green flask-like ovaries (Lowrie, 1998). The haploid chromosome number of C. follicularis is uniform (n = 10) regardless of population or habitat (Keighery, 1979). Cephalotus is an outbreeding perennial but grows slowly and takes many years to reach flowering age. Propagation through seed is slow, and seed stratification is required. Cephalotus follicularis can be regenerated from sections of root mass, a characteristic used by horticulturists for vegetative propagation; however, the number of plantlets that can be produced this way is limited. Plant tissue culture is a powerful tool for propagation of rare species, yet only a few studies of C. follicularis tissue culture have been reported. In the propagation of the C. follicularis explants, half-strength liquid LS medium resulted in a 10-fold increase in a 6-month period (Adams et al., 1979). The LS medium contains the same macroelements as the Murashige and Skoog (MS) medium but only has supplements of 100 mg·L−1 myoinositol and 0.4 mg·L−1 thiamine HCl (Linsmeier and Skoog, 1965). The goal of this study was to develop an effective method of mass micropropagation of C. follicularis.
Adams, R.M., Koenigsberg, S.S. & Langhans, R.W. 1979 In vitro propagation of Cephalotus follicularis (Australian pitcher plant) HortScience 14 512 513
Goncalves, S., Escapa, A.L., Grevenstuk, T. & Romano, A. 2008 An efficient in vitro propagation protocol for Pinguicula lusitanica, a rare insectivorous plant Plant Cell Tissue Organ Cult. 95 239 243
Hanfrey, C., Fife, M. & BuchananWollaston, V. 1996 Leaf senescence in Brassica napus: Expression of genes encoding pathogenesis-related proteins Plant Mol. Biol. 30 597 609
Hook, I.L.I. 2001 Naphthoquinone contents of in vitro cultured plants and cell suspensions of Dionaea muscipula and Drosera species Plant Cell Tissue Organ Cult. 67 281 285
Latha, P.G. & Seeni, S. 1994 Multiplication of the endangered Indian pitcher plant (Nepenthes khasiana) through enhanced axillary branching in-vitro Plant Cell Tissue Organ Cult. 38 69 71
Murashige, T. & Skoog, F. 1962 A revised medium for rapid growth and bio assays with tobacco tissue cultures Physiol. Plant. 15 473 497
Teng, W.L. 1999 Source, etiolation and orientation of explants affect in vitro regeneration of Venus fly trap (Dionaea muscipula) Plant Cell Rep. 18 363 368