IN-VITRO REGENERATION OF DENDROCALAMUS-STRICTUS NEES THROUGH NODAL SEGMENTS TAKEN FROM FIELD-GROWN CULMS

Single-node stem segments were excised from newly regenerated branches of about 10-year-old field-grown culms of Denarocalamus strictus Nees and cultured in a modified Murashige and Skoog's (1962) medium (MS) supplemented with 0.5 mg/l indole-3-acetic acid and 15 mg/l adenine sulphate. Two to four axillary shoots were produced per explant. However, the regenerated shoots ultimately died for want of rooting. A large number of treatments comprising various auxins and their combinations, with or without phenolic acids failed to induce rooting in a nodal segment with regenerated shoots. Rooting was induced (maximum 30%) following regeneration of axillary shoots, provided that the explants were cultured in an inverted position, in the rooting medium under the combined influence of 1 mg/l each of beta-indolebutyric acid and alpha-naphthaleneacetic acid, 0.5 mg/l 2,4-dichlorophenoxyacetic acid and 1 mg/l phloroglucinol at pH 5.2. Nodal explants collected during July-August responded most favourably. The in vitro-raised plantlets showed about 80% transplant success and grew normally in soil under glasshouse as well as field conditions.