Development of somatic embryos in Norway spruce

Embryogenic cell lines of Norway spruce consist of a large number ofsomatic embryos. The cell lines have been divided into two groups, A and B.The group B embryos are developmentally blocked. Extracts of mature spruceseeds stimulate group B embryos to develop a morphology comparable to groupA embryos. However, seed extract inhibits early embryo development. Theactive components in seed extract were shown probably to be proteins.Extracts of mature seeds contain chitinase-like proteins as recognized byan antibody towards chitinase 4 in sugar beet. Proteins of similar sizeswere detected by the same antibody in the conditioned medium of group A,but not in group B. A chitinase 4-related chitinase and a nod factor had astimulating effect on early embryo development, but did not influence thelater stages of embryo development.Key words: Piceaabies, somatic embryogenesis, embryo development, seed extract.