Advances in Conifer Somatic Embryogenesis Since Year 2000

Abstract

This review compiles research results published over the last 14 years on conifer somatic embryogenesis (SE). Emphasis is placed on the newest findings that affect the response of seed embryos (typical explants) and shoot primordia (rare explants) to the induction of SE and long-term culture of early somatic embryos. Much research in recent years has focused on maturation of somatic embryos, with respect to both yield and quality, as an important stage for the production of a large number of vigorous somatic seedlings. Attempts to scale up somatic embryo production numbers and handling have resulted in a few bioreactor designs, the utility of which may prove beneficial for an industrial application. A few simplified cryopreservation methods for embryonal masses (EM) were developed as a means to ensure cost-efficient long-term storage of genotypes during clonal field testing. Finally, recent long-term studies on the growth of somatic trees in the field, including seed production yield and comparison of seed parameters produced by somatic versus seed-derived trees, are described.

Simple and efficient protocols for the initiation and proliferation of embryogenic tissue of Douglas-fir

“…Somatic embryogenesis is the primary technology facilitating the delivery of all conifer biotechnology services and products, including rejuvenation of stock, cryopreservation of genetic resources, transgenic trees and field-proven clonal planting stock (Park et al 2006; reviewed in; Lelu-Walter et al 2013;Klimaszewska et al 2015). The combination of somatic embryogenesis with genetic transformation technology may prove to be very useful for Douglas-fir as far as creating sexual sterility is concerned.…”

Global Lysine Acetylome Analysis of Desiccated Somatic Embryos of Picea asperata

“…To date, somatic embryogenesis has been achieved in a variety of coniferous species (Klimaszewska et al, 2016). However, the low germination rate of mature somatic embryos is a major limitation that prevents the application of somatic embryogenesis for plant propagation on a large scale.…”

Tissue Culture of Corymbia and Eucalyptus

“…Shoot-tip and axillary-bud cryopreservation has proven challenging for some eucalypts, but it has a major advantage over cool storage and synthetic seed preservation in potentially being able to store plant germplasm for many years without the need for periodic subcultures for recovery and re-storage. Cryopreservation has been used very successfully to store embryogenic callus of other tree species [36,48], but there are no reports of embryogenic-callus cryopreservation for eucalypt species.…”