Micropropagation of Cyrtanthus ‘Orange Gem’ × C. eucallus hybrid

Abstract

Cyrtanthus hybrid ‘Orange Gem’×C. eucallus R. A. Dyer was micropropagated in vitro using twin-scale and single-scale explants with attached basal plate tissue or single-scale explants lacking the basal plate tissue prepared from fresh bulbs. Twin-scale explants produced significantly more bulblets as compared with explants from a single-scale on Murashige and Skoog (MS) medium supplemented with 2.5mg/l benzyladenine (N-phenylmethyl-1H-purine-6-amine; BA) and 0.5mg/l naphthalene acetic acid (1-naphthalene acetic acid: NAA). The first visual sign of regeneration was observed 25 days after the explants were cultured on a MS medium supplemented with 5mg/l BA plus 0.5 or 1.0mg/l NAA. Bulblets were formed on the abaxial surface of the leaf-scale. Single-scale explants with attached basal plate tissue regenerated bulblets on MS medium without BA and NAA. However, when NAA was not added to the MS medium, all explants from a single-scale without attached basal plate tissue failed to regenerate and dried out in 3 weeks after establishing a culture. The highest number of bulblet and bulblet primordia per single-scale explant ranged from 4.5 to 6.7 and from 10.5 to 13.4, when cultured in medium supplemented with 2.5–5mg/l BA and 0.5–1.0mg/l NAA, respectively. The number of bulblets >5mm in diameter increased as sucrose concentration increased up to 90g/l.