Application of response surface methodology for optimization of purple coneflower plant (Echinacea purpurea)

Echinacea purpurea belongs to the family of Asteraceae which has different medicinal properties. The main goal of current research was optimization of callus induction and biomass production by using Response Surface Method (RSM). For this purpose, root and leaf explants were cultured in the ½ MS medium supplemented with different concentrations (0, 1 and 2 mg/L) of Kin either alone or with 2,4-D and NAA. Also, callus production and biomass were considered as dependent variable and different concentrations of plant growth regulators were used as optimizing parameters. Meanwhile Central Composite Design was used for optimization of callus production parameters. Correlation analysis of regression model determined a polynomial second degree which used for optimizing of callus induction and biomass production. The obtained data showed that both root and leaf explants produced callus in all investigated treatments. But the highest amount of callus induction and biomass production was achieved in leaf derived callus in medium containing 1.05 and 0.94 mg/L NAA and Kin, respectively. On the other hand, the maximum fresh weight was obtained in leaf derived callus in medium supplemented with 1.07 and 1.15 mg/L 2,4-D and Kin. The current results were almost in consistency with predicted data. The fit model was suitable and RSM was successful for optimization of callus induction and biomass production.