Plant Cell and Tissue Culture 39-40 (1992)
S. Narayanaswamy

Activated Charcoal (Carbonised Wood)

Though not a growth regulator, finely powdered wood charcoal is sometimes added to tissue culture media, to bring about changes in the composition of the medium. Being porous, it serves to adsorb tissue exudates in culture which are toxic, and this prevents inhibition of growth, promotes embryogenesis/organogenesis in the form of shoots/roots in particular genotypes. Certain phenolic substances which are inhibitory to growth are adsorbed by wood charcoal. Growing cells (in suspension of carrot, Haplopappus and Allium excrete large quantities of phenylacetic acid and P-OH benzoic acid (carrot), pelargonic and caprylic acids (Haplopappus), and 2, 6-OH benzoic acid (Allium) and possibly showed negative effects on differentiation. Presence of wood charcoal in the medium, promotes somatic embryogenesis possibly by adsorption of metabolites inhibiting morphogenesis (Fridborg et al., 1978); Ammirato, 1983) and pollen embryogenesis in Anemone and Nicotiana (Johannson, 1983). Beneficial effects of addition of vegetable charcoal to media are highlighted by several researchers (Constantin et al., 1977; Evers, 1984; Peck and Cummings, 1986; Misson et al., 1983)