Plantlet Regeneration from the Hypocotyl Callus of Acacia auriculiformis - Multipurpose Tree Legume

Acacia auriculiformis A. Cunn. ex. Benth. hypocotyl explants (5 -10 mm length) were excised from 10-day-old seedlings in vitro and cultured on modified MS medium with KN, BAP, 2,4-D and NAA singly or in combination. BAP (1 mg/L) and NAA (0.5) + BAP (1.0 mg/L) showed the highest morphogenetic response. Glutamine enhanced the percentage frequency of calli showing shoots and number of shoots per explant compared with arginine and media lacking them. The organogenetic capability of the callus declined when the sucrose concentration in MS medium was increased from 30-50 g/L; at 60 g/L no shoots were developed and the callus turned black. The excised shoots developed roots with IBA and IBA+NAA, and plantlet regeneration was achieved.