Propagation of Leatherleaf Fern (Rumohra adiantiformis) from Rhizomes by In vitro Techniques

Among Floricultural plants, ornamental foliage plants have gained preference over flowering plants because; those plants can be used for a longer period of survival indoors. From them, ferns play a major role in the wholesale and retail florist business because of its popularity as ornamental plants and cut fronds. One of the most attractive ferns is the “leatherleaf fern” of family Dryopteridaceae. A novel micropropagation protocol for leatherleaf fern (Rumohra adiantiformis (G. Forst.) Ching) was successfully established using rhizomes as the explant. Murashige and Skoog (MS) medium containing 0.5 mg/L Kinetin (KIN), 1.0 mg/L 6-Benzylaminopurine (BAP) and 0.1 mg/L, 1- Naphthalene acetic acid (NAA) with 30 g/l sucrose was the most appropriate medium for culture initiation with the highest number of fronds (36) and rhizomes (20). R. adiantiformis cultures could be successfully proliferated using full-strength MS medium supplemented with 0.1 mg/L BAP, 0.1 mg/L NAA, 1.0 mg/L KIN and 0.1 mg/L BAP, 0.2 mg/l NAA, 1.0 mg/l KIN. Both hormonal combinations showed the highest proliferation rate (6.28) of regenerated rhizomes with no significant difference at P≤0.05. For commercial scale propagation of leather leaf fern, the treatment which contained 0.1 mg/l BAP, 0.1 mg/l NAA, 1.0 mg/l KIN was selected as the most suitable medium and the efficiency of the medium was observable from the first subculture through to the fourth subculture. The level of multiplication peaked in the fifth subculture and retained high quality until the sixth subculture. From the seventh Rumohra adiantiformis subculture onwards, the quality of regenerated fronds was reduced. Effective rooting was undertaken on 50% MS basal medium + glucose (15 g/L) + Ascorbic acid (100 mg/ L) and gelled with 0.8% (w/v) agar supplemented with NAA 1 mg/L with highest number of roots (6-8), 12-15 days after inoculation. All the acclimatized plantlets showed 100% survival percentage after 30 days.