Final report : somatic embryos for germplasm storage and clonal propagation

Genotypes, including cultivars, of these crops currently can be conserved only as plants growing in a plantation or vineyard setting. This method of conservation is so expensive as to have mitigated against conservation of these crops as well as others like them. Preserving both the genetic diversity and the genetically fixed phenotypes of such crops is of paramount importance in order to ensure an adequate genetic base for future improvement and to meet changing environmental stresses. Successful implementation of this project would eliminate the primary expense of germplasm conservation by allowing cultivars to be maintained as clonal somatic embryos (instead of intact plants), which then could be kept more efficiently in conventional seed germplasm repositories. Many other crops and native species cannot currently be conserved for similar reasons; this represents a critical problem as native plants are destroyed due to population growth. During this project, the authors advanced toward the goal of storable somatic embryos by: (1) increasing the number of genotypes from which useful cultures can be recovered; developing a highly refined culture system for initiating and manipulating embryos;(3) refining methods to control embryo maturation and plant recovery; and (4) evaluated various methods to dehydrate and/or cryopreserve embryos for prolonged storage. As a direct result of this project, a significant literature base has emerged that has increased awareness of clonal germplasm conservation among a wide international audience. Appendices include numerous published journal articles by the authors. (Author abstract)