XVI International Botanical Congess

Maize embryo sacs isolated with minimal nucellus or completely isolated using digestive enzymes have been difficult to see or were damaged. We developed a new method involving mechanical sectioning of maize ovaries using the Vibratome. Sections containing intact embryo sacs are viable and in vitro development is normal on semi-solid Murashige-Skoog media. Embryo sacs produce endosperm (90%) and embryos (75%), and mature plants are obtained without callus formation or somatic embryogenesis. Applications of this technique include experimental fertilization and embryogenesis as well as genetic manipulation. Targeting of individual cells was demonstrated using microinjection and confocal microscopy. Our methods provide a unique way of studying maize embryo sac development and transformation. Key words: zygotic embryogenesis: endosperm, in vitro, Vibratome, microinjection.