In: PARK Y.-S., BONGA J.M., MOON H.-K. (Eds), Vegetative Propagation of Forest Trees. Korea Forest Research Institute. Seoul, Korea, pp. 572-606. Published online 05/03/2016, http://www.iufro20902.org/.
Trontin JF, Teyssier C, Morel A, Harvengt L, Lelu-Walter MA
Collaboration FCBA Pierroton, INRA Orléans
Maritime pine is a major species in Europe, especially in France, Portugal and Spain. This species has been subjected to advanced forestry and genetic breeding since the early sixties in France. However, there are strong limitations to genetic betterment of the species by traditional improvement methods because of a long generation time, high genetic load as well as a high genetic redundancy within the breeding population. Sudden and drastic socio-economic and environmental changes in recent years would need a significant paradigm shift in current breeding technology to deliver suitably tested tree varieties in plantation forestry, i.e., there is a need for multi-varietal forestry targeting over a wide range of end-products through various sylvicultural regimes. Field comparison of vegetative propagules is a key towards individual clonal selection and efficient capture of the best genetic stocks. Highly efficient clonal propagation technology is also required for scaling up production of improved varieties. Somatic embryogenesis is considered as the key technology to fulfil such requirements in maritime pine. The species is characterized by increased recalcitrance to vegetative propagation through conventional cuttings as trees are reaching their adult vegetative or reproductive phase. Somatic embryogenesis initiation from mature trees is still challenging in conifers. Therefore, the approach developed for maritime pine is postponed propagation of tested trees by combining somatic embryogenesis initiation from immature zygotic embryos and stable cryopreservation of juvenile embryogenic tissue. This review describes recent achievements and challenges towards efficient somatic embryogenesis as a key technology for multi-varietal forestry with maritime pine.