Plant regeneration from leaf-derived callus in <i>Plectranthus barbatus</i> Andr. [Syn.: <i>Coleus forskohlii</i> (Wild.) Briq.]

Abstract

A protocol was developed for Plectranthus barbatus for high frequency shoot organogenesis from leaf derived callus of aseptically grown plantlets derived from mature plant explants of high yielding clones (yield of forskolin 1.5 to 1.9%) on Gamborg medium (B₅) medium supplemented with 2 mg/l 2,4- dichloro phenoxy acetic acid (2,4-D). Shoots were regenerated from the callus on MS medium supplemented with 6-benzyl amino purine (BAP) (2 mg/l) + naphthalene acetic acid (NAA) (1 mg/l). The highest rate of shoot multiplication was achieved at the 6th subculture and more than 2000 shoots were produced from callus clump. Roots were induced from shoots of in vitro grown plantlets on basal half strength MS medium and high rooting frequencies were obtained. Regenerated plants were easily acclimatized in greenhouse conditions and later transferred to soil with 100% survival. The procedure here allows the micropropagation of P. barbatus in five months of culture and proliferated cell masses which could be used for studies of organic compounds of pharmaceutical interest.

Keywords: Callus culture, medicinal plant, root induction, shoot organogenesis

African Journal of Biotechnology Vol. 12(18), pp. 2441-2448