Regeneration via organogenesis in callus cultures of Argyrolobium roseum

A reproducible protocol has been developed for high frequency plant regeneration from immature embryos of Argyrolobium roseum Jaub & Spach, an important medicinal legume. Green nodular calli were initiated from immature embryos excised from 10-d-old pods in 70 % of cultures within 3 weeks when grown on Murashige and Skoog (MS) medium supplemented with 0.5 mg dm⁻³ benzylaminopurine (BAP) + 0.25 mg dm⁻³ indole-3-acetic acid (IAA). Subsequent transfer of 5 mm² callus pieces to MS medium supplemented with BAP (0.5 mg dm⁻³) alone or in combination with IAA (0.25 mg dm⁻³) facilitated regeneration of multiple shoots. Organogenic calli bearing multiple shoots when transferred to MS medium supplemented with BAP (0.5 mg dm⁻³) + IAA (0.25 mg dm⁻³) supported rapid shoot elongation. Shoot propagules subcultured to Gamborg's medium (B5) with 0.5 mg dm⁻³ indole-3-butyric acid (IBA) rooted with 80 % frequency and developed into phenotypically normal plants. Plantlets were successfully acclimatized in a sterile mixture of sand and garden soil (1:1) under greenhouse and thereafter transferred to field beds.