Fig. 3

Effect of immersion frequency on total alkaloid accumulation of D. nobile after a 20 days, b 40 days, c 60 days and d 80 days of culture. SC means semi-solid system culture as a control. Data represents the mean ± standard error of three replicates. Bars followed by a different letter denote significant statistical differences (Tukey, P ≤ 0.05)