Embryolike structures from cotyledons and ripe embryos of Norway spruce (Piceaabies)

Abstract

Embryos from imbibed ripe seeds and cotyledon expiants of 7-day-old Norway spruce (Piceaabies (L.) Karst.) seedlings produced the early stages of somatic embryogenesis. Using a modified Murashige and Skoog medium, a whitish, glossy callus was induced consisting of translucent cells embedded in a mucilaginous cloudy matrix. This embryogenic callus formed on the surface of explants treated first with N-6-benzyladenine followed by 2,4-dichlorophenoxyacetic acid + 6-furfurylaminopurine (kinetin) + N-6-benzyladenine. Transfer of this callus to media lacking growth regulators resulted in the formation of numerous bipolar embryoids with suspensorlike structures. These embryoids strongly resembled repressed embryos in polyembryonic seeds.