Induction of somatic embryogenesis in conifers
The genus Picea, the spruces, is a member of the Pinacea, the largest family of conifers. In vitro culture techniques, particularly somatic embryogenesis, provide an alternative means to rapidly clone large numbers of plants with improved characteristics cost effectively for direct use by forest nurseries. Somatic embryogenesis may be induced from elite seed of known parents from tree improvement programs. Somatic embryogenesis also provides a regeneration system suitable for producing genetically modified plants. Spruce somatic embryos tend to arise usually within four to six weeks of plating; however, they sometimes appear as early as two weeks after plating if immature zygotic embryos are used as explants. Conifer somatic embryos provide excellent material for light microscopic observation. Embryos can be examined in a bright field compound microscope either unstained or using a simple aceto-orcein stain, which colors the nuclei and chromosomes red.