Ontogenesis of the Somatic Embryogenesis of Habanero Pepper (Capsicum chinense Jacq.)

The ontogenesis of direct high-frequency somatic embryogenesis of C chinense induced from hypocotyl was characterized through a histological analysis of the different phases in the histodifferentiation process during the development of the somatic embryo. The anatomical analysis was carried out since the hypocotyl segments were placed in the culture medium until 45 days of culture. The somatic embryos were induced and maintained in Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (9.5 mu M). Samples of tissues and organs were taken every 24 h, fixed in formalin acetic alcohol, and embedded in plastic resin. They were cut into serial sections (5 mu m) and stained with toluidine blue. The analysis revealed that the proembryogenic cells originated just from provascular bypocotyl cells. Provascular cells acquired the embryogenic competence 48 h after induction and an intense mitotic division was observed and embryogenic structures were generated first along the vascular strands, which subsequently, evolved into somatic embryos. After 2 weeks, there were observed embryos at different stages of development (preglobular, globular, heart-shaped, torpedo-shaped, and cotyledonary). This is the first report dealing with the ontogenesis of the direct somatic embryogenesis of C chinense, and it is the most complete histological characterization carried out on somatic embryogenesis in the Capsicum genus to date.