Growth and development response of callus segments of I. gabonensis were examined using tissue culture techniques. Explants were aseptically placed and inoculated on Murashige and Skoog (MS) callus induction medium of full-MS, 1/2 MS and 1/4 MS strengths, each supplemented with the following concentrations of plant growth regulators (PGR); To (control) - treatment without plant growth regulator, T1 - treatment containing 0.1 mg/l kinetin + 2.0 mg/l NAA, T2- treatment containing 0.2 mg/l kinetin + 4.0 mg/l NAA, T3- treatment containing 0.3 mg/l kinetin + 6.0 mg/l NAA, T4- treatment containing 0.4 mg/l kinetin + 8.0 mg/l NAA and T5- treatment containing 0.5 mg/l kinetin + 10.0 mg/l NAA. The fresh weight, dry weight, moisture contents, chlorophyll a and b contents of callus segments of the species significantly (P< 0.05) increased with increase in concentration of plant growth regulators and with decrease in medium strength. The optimum growth and development response were recorded at one quarter strength medium relative to full and half strengths media. Therefore, this study provides baseline information for optimum callus induction protocols and continuous domestication of this over exploited species.
