Clonal Propagation and Tree Improvement using Somatic Embryogenesis, 2000 Pulping / Process & Product Quality Conference Proceedings

B. Sutton, S. Attree, Y. El-Kassaby, D. Cyr--Somatic Embryogenesis can be used to store juvenile material capable of regenerating somatic embryos of elite individuals in a sustained manner. The technology is being applied to capture elite families and deploy clonal tests in radiata pine, loblolly pine, slash pine, Douglas-fir and spruce. Studies of somatic embryo development have demonstrated that embryo yield and quality can be substantially improved by progressive increases in ABA concentration and non-permeating water stress during the course of embryo maturation. These improvements result in a high degree of desiccation tolerance and germination vigour which are key factors in allowing storage and subsequent sowing of embryos to nursery environments during mass production. Mass production combined with clonal selection offers an integrated system to deliver genetic improvement to the field, which bypasses seed orchard production, its associated infrastructure and time constraints. The prospect of large-scale clonal forestry requires an appropriate deployment strategy, that addresses, not only the economic efficiencies that may be realized, but also the genetic diversity and genetic gain achieved. Approaches, based on the principles of population genetics, have been developed to optimize both the initial selection strategy and clonal deployment for these latter two criteria.