Micropropagation of Combretum ovalifolium Roxb.: a medicinally important plant

The nodal explants of C. ovalifolium were cultured on Murashige and Skoog (MS) medium augmented with either [6-benzyladenine (BA) or kinetin (Kn) or thidiazuron (TDZ) or N6-(2-isopentenyl) adenine (2 ip)]. The maximum percentage response (100%) with highest number of shoots (5.0 +/- 0.9) with longest shoot (3.7 +/- 0.5 cm) per nodal explants were obtained on MS medium containing 5 mg/l BA after 45 days of culture. Shoot regenerated on MS medium supplemented with 5 mg/l BA as well as from other cytokinin shows callus formation at the base of stem; hence these shoots are not suitable for further use. The possible reason of callus formation could be ascribed to the activity of endogenous auxin. To prevent callus formation, nodal explants were cultured on MS medium supplemented with combination of BA and 2,3,5-tri-iodobenzoic acid (TIBA) or BA with TIBA and activated charcoal or BA with TIBA and adenine sulfate (AdS). Nodal explants inoculated on the MS medium augmented with 5 mg/l BA, 3 mg/l TIBA and 30 mg/l AdS have not only prevented callus formation but also produced significantly maximum number of shoots (7.5 +/- 0.3) having shoot length of 4.7 +/- 0.2. Maximum number of roots (6.3 +/- 0.4) and root length (5.3 +/- 0.1 cm) per explant was observed on half-strength MS medium containing 2 mg/l indole 3-butyric acid.