Effect of Cytokinins on Micropropagation of Teak (Tectona grandis L.) Grown in Cote D'ivoire

Teak (Tectona grandis L.) is a timber tree highly prized on world markets for its stability and durability. This hardy species has good initial growth and is very important for the reforestation of Côte d'Ivoire. However, teak regeneration potential by seed or cutting still very weak. This situation is a major constraint to planting material production in quantity and quality. The aim of this study is to improve the production of teak seedlings for orchard renewal using in vitro culture methods. Mature teak seeds were surface disinfected and sown on Murashige and Skoog (MS) basal medium supplemented with different concentrations of Benzyl-aminopurine (BAP), Kinetin and Thidiazuron (TDZ). The shoot tip explants and nodal segments were taken from in vitro germination and placed on the same medium used for seeds germination. Leafy shoots obtained after four weeks of culture were excised and transferred individually on different strength of McCown Woody plant medium supplemented with various concentrations of AIB for rhizogenesis. Teak seeds germination started seven days after sowing. BAP and Kinetin exhibited highest percentage of normal seedlings (83.46% and 74.14% respectively). Higher seedlings (7.48 cm) were obtained on medium supplemented with 0.5 mg/L kinetin. The shortest bud break time (7.43 days) was observed on medium containing 0.5 mg/L BAP. Leafy shoot production was optimal (5 leafy shoots per explant) with the nodal segment on culture medium containing 2 mg/l BAP. Half strength of McCown Woody plant medium containing 60 g/L sucrose and 4 mg/l AIB induced the highest rooting percentage (73%) and roots number per plant (03) natural environment.