Abstract

Vegetatively propagated material offers many advantages over seed material in forest tree breeding research and in reforestation programmes. Evidence is accumulating to suggest that using somatic embryos in forestry is a viable option. However, before somatic embryos can be used optimally in forestry, basic research aimed at increasing the number of responsive genotypes as well as the age of the primary explant is needed. This in turn requires the establishment of a basic understanding of the physiological and molecular processes that underlie the development of somatic embryos. The functions of genes and their developmental and tissue specific regulation are studied using transient and stable transformation techniques.The process of somatic embryogenesis can be divided into different steps: (1) initiation of somatic embryos from the primary explant, (2) proliferation of somatic embryos, (3) maturation of somatic embryos and (4) plant regeneration. Cortical cells in the primary explant are stimulated to go through repeated divisions so that dense nodules are formed from which somatic embryos differentiate. The first formed somatic embryos continue to proliferate and give rise to embryogenic cell lines. Embryogenic cell lines of Picea abies can be divided into two main groups A and B, based on morphology, growth pattern and secretion of proteins. Our results suggest that extracellular proteins play a crucial role in embryogenesis of Picea abies. Somatic embryos from group A can be stimulated to go through a maturation process when treated with abscisic acid. Mature somatic embryos can develop into plants.

Keywords

conifer; cryopreservation; embryogenic cell lines; embryo morphology; extracellular proteins; Norway spruce; Picea abies; somatic embryogenesis; transient gene expression

Published in

Plant Growth Regulation
1996, Volume: 20, number: 1, pages: 3-9

SLU Authors

• Von Arnold, Sara

  • Department of Forest Genetics, Swedish University of Agricultural Sciences
    

• Clapham, David

  • Department of Forest Genetics, Swedish University of Agricultural Sciences
    

• Egertsdotter, Ulrika

  • Department of Forest Genetics, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Developmental Biology


Publication identifier

DOI: https://doi.org/10.1007/BF00024050

Permanent link to this page (URI)

https://res.slu.se/id/publ/88505