Abstract
Delonix regia (Boger.) Raf. (Royal Poinciana) 'Yellow Kampong' is a very attractive ornamental flowering tree with showy yellow flowers. In South Florida, Royal Poinciana has commercial value and interest for nursery production and potential for use in the landscape. Although Royal Poincianas grow best from seed, seed propagation has several limitations and rooting of cuttings is reportedly inefficient. Furthermore, the 'Yellow Kampong' has very low seed production. Hence, we successfully induced somatic embryogenesis in Royal Poinciana. Cultures were initiated from immature zygotic embryo, comparing two levels of plant growth regulators for the rate of embryogenic induction: 0.5 mg L[sup-] of 2,4-D + 0.1 mg L[sup-] of BA (D1) and 1.0 mg L[sup-] of 2,4-D + 0.125 mg/L of BA (D2). Some contamination was observed at culture establishment and contaminated cultures were discarded. Somatic embryos developed from both treatments. However, treatment D2 had a somatic embryo formation rate of 26.2% compared to 2.4% for D1. Future perspectives include additional studies with plant growth regulators to obtain higher embryogenic rates. Current studies include the establishment of regenerated plantlets for subsequent transplanting to the greenhouse. This technique provides a means for the propagation of Royal Poinciana and a model for other woody species that are difficult to propagate by conventional methods. This is the first report of somatic embryogenesis in Royal Poinciana 'Yellow Kampong'.
