The effect of meta-Topolin (mT), an aromatic natural cytokinin, on growth and lateral bud formation was evaluated on axenic explants of agarophytic red seaweed species viz. Gracilaria foliifera and G. crassa collected from Andaman and Nicobar Islands. Explants were aseptically established under in vitro condition using antibiotic solution consisting of streptomycin sulphate, nystatin, rifampicin and erythromycin followed by detergent (0.1% for 10 min) and betadine at 1% concentration.
Our experimental model consisted of axenic explants of seaweeds cultured in vitro onto micro-filtered autoclaved seawater based media supplemented with 2.5 mg L-1, 5 mg L-1 and 7.5 mg L-1 mT or 6-Benzylaminopurine (BAP) for 15 days. The in vitro effects of similar concentrations of mT were more profound when compared with that of equivalent concentrations of BAP. Among this micro-filtered seawater supplemented with mT at a concentration of 7.5 mg L-1 promoted maximum weight gain, daily growth rate, total chlorophyll contents, total carotenoid contents and lateral bud formation when compared with other concentrations control. The results indicate possible application of mT as a potent cytokinin for in vitro culture of G. foliifera and G. crassa.