Induction of Somatic Embryos in Five Varieties of Hibiscus sabdariffa

Hibiscus sabdariffa, also referred to as sorrel or roselle, is a tropical crop grown for its colorful fleshy and tart calyx.  The ability to apply molecular breeding to sorrel for plant improvement is inhibited by the lack of a protocol for somatic embryogenesis and regeneration. The purpose of this research was to evaluate the influence of 2,4-D concentration on the induction of somatic embryogenesis from cotyledon explants of sorrel.  Seeds of six sorrel varieties (100, JAK, 128, KDN, 245, TTB) were surface disinfected and germinated in vitro. Cotyledons from two day old germinating seedlings were sliced into 1.5 mm strips and placed in petri plates containing MS medium with 60, 120, 180, 240 and 360mM 2,4-D. After four weeks embryos were observed emerging from the vascular bundle in the expanded cotyledon slices of five varieties. Successful somatic embryo induction improved as the 2,4-D concentration increased to 240 mM for the varieties 100, KDN,128, TTB and 245. 2,4-D can be used to induce somatic embryos from young cotyledon tissue in vitro.