Micropropagation of Alocasia amazonica using semisolid and liquid cultures

Abstract

An efficient, simple micropropagation method was developed for Alocasia amazonica using corms in semisolid and liquid cultures. Explants were cultured onto Murashige and Skoog (MS) medium (Murashige and Skoog, Physiol. Plant. 15:473-497, 1962) supplemented with different cytokinins (Benzyladenine [BA, 2.22-13.32 μM], kinetin [2.32-13.95 μM], Thidiazuron [TDZ, 0.45-4.54 μM]) and cytokinin in combination with auxins [naphthalene acetic acid (NAA, 0.54-5.37 μM)/indole acetic acid (IAA, 0.57-5.71 μM)/indole butyric acid (IBA, 0.49-4.9 μM)]. All supplementary-induced shoot proliferation and the optimal results was on the medium supplemented with 2.27 μM TDZ, which induced 5.1 shoots per explant. Among the different concentrations of sucrose (0-120 g l −1 ) tested for shoot proliferation, 30 g l −1 was found suitable for corm cultures of Alocasia amazonica. The optimal shoot proliferation and biomass values were with the plantlets grown at 30 μmol m −2 s −1 photosynthetic photon flux (PPF) and 25°C. Liquid cultures found suitable for shoot proliferation and biomass accumulation was compared to semisolid cultures. Comparative studies of bioreactor systems [continuous immersion (with or without net) and temporary immersion in liquid media using ebb and flood] revealed that shoot multiplication and growth were greatest with the raft bioreactor system. Plantlets (cormlets) from the bioreactor were hydroponically cultured for 30 days, and 100% of plants were acclimatized successfully. The simple efficient method of production of plantlets (cormlets) is useful for large-scale multiplication of this important ornamental plant.

In vitro sucrose concentration affects growth and acclimatization of Alocasia amazonica plantlets

“…Alocasia amazonica (Araceae) commonly called 'Elephant's ear', is an evergreen ornamental perennial plant with a long rhizome and a short stem (Jo et al 2008a). The cross hatch pattern of white lines over its shiny dark green foliage gives it an ornamental value.…”

“…The cross hatch pattern of white lines over its shiny dark green foliage gives it an ornamental value. Alocasias are mainly propagated through corms and seeds, but the inefficiency of this conventional propagation method is major constraint in its commercial multiplication (Jo et al 2008a). In vitro methods of propagation provide an alternative to meet the demand of the market.…”

“…In vitro methods of propagation provide an alternative to meet the demand of the market. In vitro multiplication of Alocasias has been reported by few workers from axillary bud explants (Thao et al 2003a, b;Jo et al 2008a). Thao et al (2003a) not only achieved high frequency shoot regeneration with 5 mg l -1 benzyladenine (BA) on MS media using an initial axillary bud explant excised from corm of A. amazonica but also achieved rooting in the regenerated shoot in a hormone free MS medium besides 100% successful acclimatization potential.…”

“…Greater growth in thin-film liquid culture of Alocasia is most probably due to easier accessibility of sugar in liquid compared to solid medium (Adelberg and Toler 2004). Jo et al (2008a) indicated use of hydroponic bioreactor system for large scale rapid multiplication of A. amazonica. Moreover, Jo et al (2008b) also reported the best growth and development of A. amazonica growing under 15 and 30 lmol m -2 s -1 photon flux densities and short (8/16 h) and equinoctial (12/12 h) photoperiods.…”

In vitro regeneration of brahmi shoots using semisolid and liquid cultures and quantitative analysis of bacoside A

“…Recently, liquid cultures are efficiently used for in vitro multiplication and rapid growth of the propagules (Ilan et al 1995;Park et al 2000;Adelberg 2004;Kim et al 2004;Jo et al 2008). After culturing leaf explants on semisolid medium for 4 weeks, explants were transferred to MS liquid medium (50 ml liquid medium taken in conical flask/s) with the same cytokinin concentrations as in semisolid cultures.…”