Abstract: Anatomical and histochemical studies were carried out during the
somatic embryogenesis of Syagrus oleracea (Mart.) Becc. from immature
inflorescences. Immature rachillas were inoculated on Murashige and Skoog
medium with 4.52 μM 4-amino-3,5,6-trichloropicolinic acid (Picloram) and
2,4-diclorophenoxyacetic acid. Auxin concentrations were gradually reduced
for the formation of somatic embryos, while for plantlet regeneration, embryos
were inoculated on a medium without growth regulator. After 270 days, two
types of embryogenic calluses were observed in explants under the effect of
Picloram: nodular, with a smooth surface and those without definite shape, with
an irregular surface, both presenting a meristematic zone with polysaccharide
content. Callus progression to the differentiation stage allowed for the conversion
of somatic embryos, some with a well-defined protoderm and procambial
bundles. The histochemical analysis of the somatic embryos did not identify
the presence of polysaccharide and protein reserves, which emphasizes the
necessity for optimization of the maturation conditions.