In vitro clonal propagation of Clerodendrum serratum (Linn.) Moon (barangi): a rare and threatened medicinal plant

An in vitro process for rapid clonal propagation of Clerodendrum serratum (Linn.) Moon, a rare and threatened medicinal shrub, has been developed. Nodal stem segments having axillary bud, taken from field-grown plant, showed bud-break within 15 days of culture on modified Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented with 0.25 mg/l each of 6-benzylaminopurine and indole-3-acetic acid along with 15 mg/l adenine sulphate (AdS). Regenerated shoots could be further multiplied on the same agarified morphogenetic medium in presence of 0.5 mg/l 2-chloroethyltrimethyl ammonium chloride with increased concentration of AdS, i.e., 30 mg/l. A group of five shoots used as inoculum produced on an average 4.98 new shoots per original shoot after 4 weeks of subculture. Shoots excised from cultures of proliferating shoots were rooted in half-strength MS medium having 1 mg/l indole-3-propionic acid. In vitro rooted shoots—plantlets—grew luxuriantly under field conditions and came to flowering after 10 months of transplantation. The genetic fidelity of in vitro-raised field-grown plants and their mother plant was ascertained by random amplified polymorphic DNA markers. The protocol developed holds good for in vitro cloning of C. serratum.