Tissue culture of Ecklonia radiata (Phaeophyceae, Laminariales): effects on growth of light, organic carbon source and vitamins

Abstract

The effects of light quality and irradiance, and supply of organic carbon and vitamins on the growth of two forms of Ecklonia radiata in tissue culture were examined. A callus of unpigmented cells developed over the cut surface of newly excised explants of stipe. This growth was best in the dark but stopped after 10 weeks. Pigmented, mainly filamentous clumps of cells developed from explants after several weeks in culture. These required light for growth, with growth being enhanced by increasing photon flux density up to 30 /mol photon m-2 s -, with the active spectral component being red light (> 600 nm). The addition to the medium of a range of organic carbon sources or vitamins did not stimulate growth of either culture type in the dark.

The effects of glycerol and plant growth regulators on Gracilaria verrucosa (Gigartinales, Rhodophyceae)

“…The use of glycerol in combination with phytohormones induced growth for more than 12 months. Lawlor et al (1989) found a small stimulation of growth of Ecklonia radiata (Phaeophyta) in media supplemented with 1 mM or 10 mM glycerol.…”

Actual, potential and speculative applications of seaweed cellular biotechnology: some specific comments on Gelidium

“…to increase low growth rates (indicating suboptimal conditions) of seaweed tissue (Fries, 1973; and callus cultures (Nakamura, 1974;Saga & Sakai, 1983) has resulted in both stimulatory effects and no effects (Robaina, 1988;Lawlor etal., 1988). Nutrient depletion could be the reason for callus and 'callus-like' inductions or reversions (PedersCn, 1968;Fries, 1980;Bradley & Cheney, 1986;Lawlor et al, 1989). Sugars have been reported to be unnecessary or even inhibitory to tissue (Fucus spiralis: Fries, 1984), callus (Ecklonia radiata: Lawlor et al, 1989) and cell culture (Porphyra umbilicalis: Tait et al, 1990) growth or organogenesis.…”

“…Nutrient depletion could be the reason for callus and 'callus-like' inductions or reversions (PedersCn, 1968;Fries, 1980;Bradley & Cheney, 1986;Lawlor et al, 1989). Sugars have been reported to be unnecessary or even inhibitory to tissue (Fucus spiralis: Fries, 1984), callus (Ecklonia radiata: Lawlor et al, 1989) and cell culture (Porphyra umbilicalis: Tait et al, 1990) growth or organogenesis. Our studies on the interrelationship between the osmolality of the culture medium and the effect of osmotically active sugar supplementation has shown that, as in higher plants (van Rensburg & Vcelar, 1989), the effects of carbohydrates in seaweed tissue and callus culture seem osmotic or metabolic or both (Robaina et al, 1990a;1990b).…”

“…Heterotrophic growth is required for biomass production in bioreactors, but heterotrophic frowth of seaweed tissue remains to be demonstrated (Fries, 1973;Robaina, 1988;Lawlor et al, 1989;Robaina et al, 1990b). Although a callus of Gelidium has been obtained with the addition of sucrose (Nakamura, 1974), 20 g 1-' mannitol (Gusev et al, 1987), or in the absence of sugars in the culture media (Polne-Fuller & Gibor, 1987a;Garcia-Reina et al, 1988a), callus production has not occurred in darkness.…”

“…Although a callus of Gelidium has been obtained with the addition of sucrose (Nakamura, 1974), 20 g 1-' mannitol (Gusev et al, 1987), or in the absence of sugars in the culture media (Polne-Fuller & Gibor, 1987a;Garcia-Reina et al, 1988a), callus production has not occurred in darkness. However, as seaweed tissues, (Fries, 1977;1 98O), cell (Saga et aL, 1978 ;Polne-Fuller et al, 1987 ;Tait et al, 1990) and callus cultures Polne-Fuller & Gibor, 1987b;GarciaReina et al, 1988a;Lawlor et al, 1989) are phototrophic, including Gelidium species, photobioreactors remain a possibility for biomass production.…”