Abstract

Ravoniarison Nivohanintsoa Elinorovololona and *Ephrem Ludget Martial

Medinilla mandraken is a threatened epiphyte forest endemic of Madagascar. Micro propagation regeneration is an appropriate way for propagation and conservation of this species. The study aims to find the best combination of growth regulators for the rapid proliferation in vitro of shoots by nodal segment. Micro cuttings was from aseptic germination of seeds grown on Murashige and Skoog in half strength medium (MS/2), supplemented with 15% of green coconut water. The MS/2 added 0, 0.5, 1, or 2mg/L of 6- Benzylaminopurine (BAP), alone or in combination with 0.1 or 0.5 mg/L of 2-Naphtalene Acetic Acid (NAA), were tested for its multiplication. The effects of growth regulators were evaluated in function of means number of regenerated shoots, their size, callogenesis, and rooting rate. The best shoot growth was obtained in the medium growth regulators free (13.3 mm in 45 days). Culture Medium added of 2 mg/L of BAP promotes maximum proliferation of shoots (27.5 shoots per explants in 45 days). The combined use of BAP and NAA regardless of their concentrations reduced the production of shoots and improved the cals formation. Rooting was noted in the medium growth regulator free.