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Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 9/9/2013 Publication Date: 9/9/2013 Citation: Walters, C.T. 2013. Seed biology of tree species and strategies for ex situ conservation. In: Proceedings of the International Symposium on Breeding and Utilization of Forest Special Purpose Trees, September 9-12, 2013, Suwon, Korea. p.23-35. Interpretive Summary: Genebanks were originally established to preserve and use the genetic diversity of crops. The success of these operations has led to development of plant genetic resource collections for a multitude of other purposes. One such purpose is conservation of the genetic diversity of forest tree species. Genebanking germplasm from tree species is apt to bring new challenges for storage and regeneration. Several tree species produce seeds that cannot be stored using conventional technologies. In addition, because they are large and require many years to flower and fruit, regenerating trees from seeds will consume many resources. This paper discusses a few options that will provide greater flexibility to genebanking genetic resources of trees. Technical Abstract: The last decade has brought increased efforts to conserve genetic diversity of plants using ex situ strategies. Technologies used in genebanking originated with crop species and are now being applied to diverse species that show a wide range of storage physiologies. A diversity of germplasm, including seed, pollen and vegetative cuttings, present options for capturing and storing genetic diversity in genebanks. The principles of preserving germplasm are the same for the diverse array of species and propagule. However, different responses of plant cells to preservation require a variety of approaches and portend broad variation in longevity of stored germplasm. For orthodox seeds of crops, genebanks can probably achieve longevities of 80-100 years. Because tree seeds are more difficult to regenerate, a longer storage period may be desirable. This, in combination with more difficult storage physiologies, suggests that genebanking genetic resources of trees will be challenging but feasible. A combination of strategies that use different types of propagules is recommended to circumvent inherent problems associated with life history traits and seed physiology. Because of the greater complexity, genebanks for non-domesticated plants, including tree species, will need to optimize collection sizes to allow necessary resources for curation. |
