HIGH-FREQUENCY DIRECT SHOOT BUD REGENERATION FROM EXCISED LEAVES OF MANGOSTEEN (GARCINIA-MANGOSTANA L)

An improved procedure for direct shoot bud regeneration from young leaves of mangosteen (Garcinia mangostana L.) has been developed. Regeneration was achieved by culturing 3-mm transverse sections of about 10-day-old leaves on woody plant medium enriched with 20 mu M benzyladenine (BA), 20 g/l sucrose and 2.5 g/l Phytagel. A wound response in the presence of BA at the time of culture was found to be essential for shoot bud induction. Explant size, concentration of BA in the medium, timing of addition of BA to the medium as well as the time of wounding of explant significantly influenced shoot bud regeneration. Leaves from field-grown seedlings produced an average of 45 shoot buds per leaf after 50 days of culture, compared with 8 shoot buds per leaf from in vitro shoots. Regenerated shoots (5-6 mm tall) excised from the explants required BA (5 mu M) for further growth. Rooting was induced with indolebutyric acid (IBA) when the shoots reached 10-15 mm and were established in vermiculite/sand mixture in pots.