SOMATIC PROEMBRYO INDUCTION IN BIRD OF PARADISE (Strelitzia reginae Banks)

Abstract

The bird of paradise (Strelitzia reginae Banks) is a beautiful ornamental plant highly valued as cut flower. It is propagated by seed or division of old plants, although both methods are very slow. The in vitro propagation of plants through somatic embryogenesis has been established successfully for many ornamentals species. There are no reports about this process in S. reginae because this species presents serious problems of browning in the cultured explants. In this work we established a procedure for the induction of somatic proembryos (SPE) using cotyledon node fragments from plantlets 30 d old. After five months of incubation, explants cultivated on dark conditions produced SPE in Murashige and Skoog medium at 100 and 50 % strength, supplemented with 2,4-D (0.5 to 2.0 mg L^-1), sucrose (30 g L^-1) and activated charcoal (0.1 g L^-1). The SPE grew and formed structures 5 – 6 mm long, whose distal tip presented a root meristem-like cellular organization which lacked a quiescent centre. The absence of a shoot meristem in the SPE prevented the further in vitro development of proembryos.