Explants were obtained from leaves of three strains of tomato and grown on a modified Murashige and Skoog's medium with various combinations of indole-3-acetic acid (IAA) and kinetin. Callus proliferation began by 8–10 days. Root initiation was very common, particularly at 2 mg/liter IAA and 2 mg/liter kinetin. Shoot formation occurred within 30 days but only at a specific combination of concentrations of the two growth hormones (4 mg/liter IAA + 4 mg/liter kinetin). Most shoots became plantlets by 10 days after transfer to basal Murashige and Skoog's medium. Shoot-forming potential was neither correlated with callus-forming potential nor with vigor of strain.
Indole-3-Acetic Acid Metabolism in Relation to Root Initiation
