In vitro multiplication and field establishment of Adhatoda beddomei C. B. Clarke, a rare medicinal plant.

Clonal propagation of Adhatoda beddomei C.B. Clarke (Acanthaceae), a rare medicinal shrub, was achieved through callus-free axillary meristem proliferation from stem node explants of field-grown plants cultured in SH medium. Shoot multiplication was a function of cytokinin activity but sustained growth of the shoots was dependent on the synergistic effect with the auxin, IAA. An optimum number of 5-10 shoots per explant were obtained in 6 weeks using 3.0 mg.l(-1) BAP, 0.5 mg.l(-1) 2-ip and 1.0 mg.l(-1) IAA, Upon subculture, vertical halves of the precultured node with the differentiated shoots yielded a larger aggregate number of shoots (23-27) than the uncut precultured node left intact (15-17). Shoot multiplication was rapid and consistent over prolonged periods when the hormonal concentrations were reduced to 1.0 mg.l(-1) BAP and 0.2 mg.l(-1) IAA during subculture, and reculture of the nodal explants derived from shoot cultures. Rooting of 3-5 cm shoots thus obtained was greatly accelerated in stationary liquid medium containing 0.2 mg.l(-1) IBA or IAA. Hardening of the rooted plantlets in the humidity chamber was essential for high frequency (95%) survival. Micropropagated plants established in the field flowered after fifteen months and were free from apparent defects in cytological, growth and flowering characteristics.