Shoot organogenesis from leaf and stem explants of Heliotropium foertherianum Diane and Hilger

Heliotropium foertherianum Diane and Hilger ( Boraginaceae ), an evergreen shrub or tree that grows naturally on tropical atoll sandbanks above the high tide line of beaches, is used for landscaping in tropical islands but also has medicinal and ecological value. In this study, shoot proliferation and regeneration protocols were established for H. foertherianum for the first time. Adventitious shoots were successfully induced from young leaves and internode explants on Murashige and Skoog (MS) medium supplemented with 1.0 mg L –1 thidiazuron, applied alone or in combination with 0.2 mg L –1 6-benzyladenine (BA). Shoot proliferation was optimal on MS medium with 2.0 mg L –1 BA and 0.2 mg L –1 indole-3-butyric acid (IBA), achieving a shoot proliferation coefficient of 4.7 within 45 d of culture. When BA concentration was too high (> 3.0 mg L –1 ), fasciated stems and abnormal leaves formed. Adventitious roots were induced from 100% of adventitious shoots on half-strength MS medium with 2.0 mg L –1 IBA within 45 d. When rooted plantlets were transferred to a substrate of peat:vermiculite:perlite (1:1:1) ( v : v : v ), over 95% survived within 3 mo.