Somatic embryogenesis in Hypoxis hemerocallidea: An important African medicinal plant

Abstract An efficient in vitro plant regeneration system was established via somatic embryogenesis of Hypoxis hemerocallidea , an extensively utilized medicinal plant in South African traditional medicine. Embryogenic callus was obtained on Murashige and Skoog (MS) basal medium supplemented with 15 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.5 μM N 6 -benzyladenine (BA). Different developmental stages of somatic embryos (SEs: globular embryos, torpedo-shaped embryos and cotyledonary embryos) were obtained and further matured from the embryogenic callus by subsequent subculture on the same medium. Highest frequency of somatic embryos (30.56 ± 1.15) was recovered after 6 weeks. Scanning electron micrographs revealed the presence of somatic embryos. Mature somatic embryos germinated and developed into plantlets after 4 weeks on half strength MS basal agar medium. The germination frequency reached 88.9% when using half strength MS basal agar medium supplemented with 1.44 μM gibberellic acid (GA 3 ). Rooted plantlets were successfully acclimatized in the greenhouse with a survival rate of 90%. This is the first report on the establishment of H. hemerocallidea somatic embryogenesis. The protocol developed would be helpful in reducing stress on natural populations, provide a system for germplasm conservation, regeneration of large numbers of high value clonal plants for commercial production, genetic transformational studies and provides a system for analysis of bioactive compounds.