ANATOMíA Y ULTRA ESTRUCTURA DE LA FMBRIOGéNESIS SOMáTICA EN ONOTO

summary with the purpose of studying somatie embryogenesis process of annatto, bixa orellana l., from anther culture, anatomical and ultrastructural studies (scanning electron microscopy) were performed of embryogenic and non embryogenic callus, as weil as somatic embryos in four growing stages globular, heart, torpedo and cotiledonary. for anatomical studies, the samples were established in faa 70%, dehydrated in a graded ethanol - terbutanol increasing series, immersed in paraffin, sectioned between 5 and 24 pim and stained with safranine - fast green. for the ultrastructural studies, the samples were established in faa 70%, dehydrated in a graded ethanol series, dried to critica？ point and covered with gold with an ionic- metallization procedure. the embryogenic tissue was characterized by round celis, relative thick walls, dense cytoplasm and prominent nuclei. later, torpedo and cotyledonary stages were developed, characterized by hipocotyl and radicle axis'enlargement and cotyledon expansion, respectively. the formation of secondary embryos and anomalies were observed, with fonnation of many cotyledons j oined together in a small rose way. key words: anatomy; anthers; bixa orellana l.; somatic embryos; sem; ultrastructure