Using in vitro stem node cutting method in propagation of Paphiopedilum delenatii
Keywords:Paphiopedilum delenatii, cutting method, stem node, propagation.
Paphiopedilum delenatii is recalcitrant to micropropagation. Lack of high efficient method for massive production of seedlings has existed for many years. In this paper, young shoots with 4 leaves were cultured on SH medium containing 0.5 mg/l BA, 0.5 mg/l NAA, 30 g/l sucrose, 9 g/l agar and 1 g/l activated charcoal and maintained under total darkness for 4 months before transferred into fluorescent light at a PPFD of 45 μmol m−2s-1 for 2 months. After 4 months cultured under darkness, the shoots were extended for an average of 10.5 cm, with 5 leaves/ shoot, equivalent to 5 nodes/ shoot. After the next 2 months under fluorescent light, leaf formation was obtained but no stem node induction was observed. Shoots were then excised into 5 single nodes with 1 leaf and 1 root per node, and the apical shoots developed with 3 leaves and 2 roots each. Finally, nodes with well-developed root and leaf systems were grown in sphagnum moss (Taiwan) and gave the survival rate of 100% after 12 months.