DEVELOPMENTAL AND REGULATORY MECHANISMS INVOLVED IN PECAN SOMATIC EMBRYO MATURATION

Abstract

Although somatic embryogenesis in vitro has been carried out successfully in a number of plants, a limiting factor in many somatic embryogenic systems is that plantlet regeneration is not obtainable or restricted to low frequencies. We have developed a repetitive, high frequency somatic embryogenic system in pecan (Carya illinoensis) and have identified effective treatments for improved somatic embryo conversion. A 6 to 10 week cold treatment followed by a 5 day desiccation, promoted enhanced root germination and extension, and epicotyl elongation. Light and transmission electron microscopic evaluations of somatic embryo cotyledon development will be presented and related to conversion enhancing treatments and their possible roles in embryo maturation.