PLANT REGENERATION FROM MATURE ZYGOTIC EMBRYO EXPLANTS OF ACACIA CRASSICARPA A. CUNN EX BENTH. VIA ADVENTITOUS SHOOTS

Acacia crassicarpa is a valuable ornamental species for landscape greening and fiber production in Southeast Asia. In vitro multiplication of this species could be valuable for expanding plantations. To explore new approaches to propagate A. crassicarpa, we developed system to regenerate plants from mature zygotic embryo explants via adventitious shoot induction. Embryos were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of TDZ and IAA. Combinations of TDZ at 4.54-9.81 mu M and IAA at 0.57-5.71 mu M were optimum to induce callus and adventitious shoots. Medium containing 4.54 mu M TDZ and 2.85 mu M IAA yielded the highest rate of adventitious buds (76.9%). The callus with adventitious buds was subcultured to fresh medium of the same composition for adventitious shoots development, and then transferred to the medium containing 2.89 mu M GA(3) for shoot elongation. Elongated shoots rooted on half-strength MS medium with 2.46 mu M IBA within 1 month. Rooted plantlets were hardened and successfully established in soil substratum with a 97.5% survival rate.