In vitro propagation of Coleus forskohlii Briq. for forskolin synthesis.

Shoot multiplication was obtained in vitro within 20-25 d from shoot tip expiants of 30 d old aseptically germinated seedlings of Coleus forskohlii Briq., using 2 mg/1 of 6 benzylaminopurine (BA). Shoot multiplication was further enhanced with the gradual decrease in the level of BA, and its final omission after 4 months. Different auxins supplemented at the level of 0.05 mg/1 with BA did not yield better results. Seven regenerated plants showed only diploid cells in their root tips, while three plants did not. Of these, two were diploid with occasional aneuploid cells. In one plant 32 chromosomes were observed. The potential of shoot culture in vitro and use of micropropagated plants for the production of forskolin has been demonstrated.