A rapid in vitro multiplication system for commercial propagation of pharmaceutically important Cyclea peltata (Lam) Hook & Thoms. based on enhanced axillary branching

Abstract

An efficient and quick in vitro propagation of Cyclea peltata by repeated subculture of nodal cuttings has been standardized. The nodal cuttings were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations (0.5–7 mg/l) of 6-benzylaminopurine (BA) or kinetin (Kn) alone or in combination with indole-3-acetic acid (IAA; 0.5 mg/l) for culture initiation. Optimum response in terms of percent cultures responding, days to bud break and average shoot length was observed on MS medium fortified with 3 mg/l BA and 0.5 mg/l IAA. On this medium 90% cultures responded with 6.1 cm long unbranched vigorous solitary shoots in 45 days. The proliferated primary shoot emerged from the culture initiation step was incised into small nodal explants measuring a size of about 1.5 cm in length containing a single node and subcultured on multiplication medium supplemented with BA (0.5–7.0 mg/l) and IAA (0.5 mg/l). This process was repeated for another three subcultures (each of 45 days) to study the effect of subculturing on shoot multiplication. At the end of third passage 100% of nodal explants produced an average number of 14.2 healthy green shoots on MS medium supplemented with 3 mg/l BA and 0.5 mg/l IAA. The multiplied shoots were harvested and used for rooting on half-strength MS medium containing indole-3-butyric acid (IBA; 1–7 mg/l) or naphthalene acetic acid (NAA; 1–7 mg/l) for 45 days. The best rooting response was achieved on half-strength MS medium supplemented with 5 mg/l IBA. Here 96% cultures responded with an average number of 4.1 roots per shoot. Of the 40 plants transplanted to soil 28 survived (70%). This cost effective protocol will help the mass multiplication of C. peltata for commercial propagation.