In vitro propagation of the Chinese medicinal plant, Dendrobium candidum Wall. Ex Lindl., from axenic nodal segments

摘要

Dendrobium candidum Wall. Ex Lindl. is an important species used in the formulation of Shih-hu, a Chinese traditional medicine. An efficient protocol for in vitro propagation of D. candidum using the axenic nodal segments of the shoots, originated from the in vitro germinated seedlings, was developed. The seeds from 120-d-old capsules after pollination were first germinated on half-strength Murashige and Skoog (MS) basal medium supplemented with 30 g l(-1) sucrose. After 4 mo., the seedlings were subcultured on a similar medium supplemented with 1 ml l(-1) HYPONeX, 80 g l(-1) potato homogenate and 2 g l(-1) activated charcoal for further growth. Axenic nodal segments excised from 9-mo.-old seedlings were cultured on the medium in the presence of 2 mg l(-1) benzyladenine (BA) and 0.1 mg l(-1) naphthaleneacetic acid (NAA). After 75 d, 73.2% of the explants gave rise to buds/shoots. The elongated shoots were rooted on the medium containing 0.2 mg l(-1) NAA and the plantlets were successfully acclimatized in soil.