Shoot organogenesis of 14-day-old callus transferred to regeneration media for 4 weeks. (a) Morphology of ANT39 and TN11 callus during shoot organogenesis. (b) Shoot regeneration frequency. Plantlets higher than 1 cm were recorded. Data are mean ± standard error (n=3). ** denotes significant difference between ANT39 and TN11 based on the level of 0.01.