In Vitro Plant Regeneration from Immature Leaflets Derived Callus of Acacia confusa Merr via Organogenesis

An efficient plant regeneration system was established from immature leaflet-derived callus of Acacia confusa Merr., through organogenesis. Under optimized culture conditions, the high rate of callus induction and proliferation was obtained in 35 days on MMS medium supplemented with 2,4-D (3 mg l⁻¹) + NAA (0.01 mg l⁻¹) + Kin (0.05 mg l⁻¹). The highest percentage of shoot regeneration response (95%) and greatest number of shoots (52.9) were obtained after the 46-day transfer of green nodular calli onto the shoot regeneration medium (WPM) supplemented with the BA 3 mg l⁻¹ + NAA 0.05 mg l⁻¹ + Zeatin 0.1 mg l⁻¹ + AdSO₄ 5 mg l⁻¹ combination. Efficient shoot elongation was achieved by transferring the clusters of adventitious shoot buds to medium (half-strength MS) containing GA₃ (1 mg l⁻¹) and BA (0.05 mg l⁻¹), within 30 days. The elongated shoots were rooted on half-strength MS medium supplemented with 4 mg l⁻¹ IBA and 0.05 mg l⁻¹ Kin in the 42-day culture. Rooted plantlets were hardened and successfully established in soil. The field-established plants were morphologically normal and fertile.