Multiplication of Corymbia ptychocarpa subsp. aptycha via tissue culture

ABSTRACT

Corymbia ptychocarpa subsp. aptycha, a member of Myrtaceae, is native to north-western Australia. It was introduced to China for ornamental landscape applications because of its unique leaves and beautiful terminal inflorescences. An efficient micropropagation protocol is needed for the mass propagation of Corymbia ptychocarpa subsp. aptycha. Disinfested shoot tips with one axillary bud (1.0–1.5 cm) were cultured on Murashige and Skoog (MS) medium containing 6-benzylaminopurine (6-BA) and 1-naphthaleneacetic acid (NAA). After culture for 30 days, the highest induction rate (93.3%) was observed on MS medium plus 0.5 mg L^–1 6-BA and 0.1 mg L^–1 NAA. The induced shoots were cultured on MS medium supplemented with 6-BA and NAA. A total of 5.2 shoots per explant were induced on MS medium plus 1.5 mg L^–1 6-BA and 0.2 mg L^–1 NAA. Shoots (<2.0 cm) were subcultured on half-strength MS medium containing indole-3-butytric acid (IBA) or NAA to form roots. The highest rooting rate (96.3%) was observed on the half-strength MS medium with 1.5 mg L^–1 IBA. The rooted plantlets developed well and were suitable for transplanting.

Keywords:

• Propagation
• tissue culture
• buds
• rooting
• Corymbia ptychocarpa subsp. aptycha