Optimization of Callus Induction and Cell Suspension in Catharanthus roseus

Periwinkle (Catharanthus roseus) has been considered as an important medicinal plant because it contains many alkaloids such as vincristine and vinblastine. In vitro culture of periwinkle provides new tissue sources such as callus, cell suspension and seedlings to produce secondary metabolites. As for the mass production of callus and cell suspension in order to optimize the extraction of secondary metabolites have been few studies, the present study describes two callus production optimization procedures and one cell suspension experiment. The first trail was a factorial experiment with three explants (roots, shoots and leaves) on Murashige and Skoog (MS) medium supplemented with different concentrations of BAP and 2,4-D. The second trial was a factorial experiment with six explants (roots, shoots, in-vitro grown leaves, ex-vitro grown leaves, seeds and nodes) and ten different hormonal combinations. The cell suspension experiment was conducted with six hormonal and one control (without hormone) treatments based on completely randomized design. Comparison of means showed that the maximum callus production was obtained from leaf explants, the root and shoot explants were in the second orders. In overall, 0.5 mg /l BAP + 1 mg/l 2,4-D and 0.5 mg /l KN + 1 mg/l 2,4-D concentrations proved to be optimal for the production of maximum callus. The best combination for suspension culture was 1 mg/l 2,4-D and/or 2 mg/l 2,4-D+1 mg /l BAP according to the dried cell weight.