In vitro micropropagation, flowering, and tuberization of Ceropegia maculata Bedd.—an endemic plant of Southern Western Ghats

Ceropegia maculata Bedd. is an endemic plant of Southern Western Ghats, Tamil Nadu, India. It has important medicinal properties, edible tubers, and ornamental flowers. In vitro propagation protocol of this plant is required and is established by using nodal explants. Sterilized nodal explant was inoculated on Murashige and Skoog (MS) medium supplemented with various plant growth regulators (PGRs) and additives for in vitro shoot multiplication. Maximum shoot induction (86%) with an average of 2.43 shoots per explant was obtained on MS medium supplemented with 1.5 mg L of N6-benzyl adenine (BA). The highest number of shoots (6.66) per explant was observed on MS medium containing combination of 1.5 mg L BA and 0.5 mg L indole-3-butyric acid (IBA). In this study, in vitro flowering (93.33% and 4.86 flowers per mature shoot) on MS medium plus 0.5 mg L BA and tubers (95.33%) on MS medium plus combination with 2.0 mg L BA with 0.5 mg L naphthalene acetic acid (NAA) were observed. The highest number of roots (9.33) per shoot was recorded on half-strength MS medium supplemented with 0.5 mg L IBA. The rooted plantlets were hardened with sand and coconut coir mixed with red soil 1:1:1 (w/w/w) ratio. Acclimatized plants were transferred to field and survival rate was 90%. For the first time, developed this protocol allows an efficient method for in vitro plant regeneration and conservation of this endangered species.