Submitted to: Proceedings of Plant Growth Regulation Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 31, 2010
Publication Date: November 30, 2010
Citation: Reed, B.M. 2010. Micropropagation and cryopreservation: alternative techniques for conserving plant genetic resources. Proceedings of Plant Growth Regulation Society of America. p. 58-64. Interpretive Summary: Vegetatively propagated crops must be maintained as growing plants in fields or greenhouses. Growing plants are often at risk of loss from disease, environmental hazards or weather so it is important to have secure secondary collections in place. Micropropagation (tissue culture) and cryopreservation (storage in liquid nitrogen) are used for backup of the temperate fruit, nut and specialty crops held at the U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR) near Corvallis Oregon. Tissue culture collections of over 1200 accessions of 8 genera including many species and cultivars are held in medium-term storage as shoot cultures at 4°C or in long-term storage as meristems in liquid nitrogen. The diversity of the collections provides multiple challenges to micropropagation. For example the 192 accession in-vitro pear collection includes 19 species and 154 named cultivars. Research in progress includes optimization of growth media and storage conditions for the wide range of genetic diversity in the collection as well as improved cryopreservation protocols. Cryopreservation techniques were developed for the genera at NCGR and many accessions are in long-term storage in liquid nitrogen.
Technical Abstract: Genetic resources of vegetatively propagated crops are maintained as growing plants and are often at risk of loss from disease, and environmental hazards. Micropropagation and cryopreservation are used for backup of the temperate fruit, nut and specialty crops held at the National Clonal Germplasm Repository (NCGR) Corvallis, OR. Tissue culture collections of over 1200 accessions from 8 genera including many species and cultivars are held as shoot cultures in low temperature storage (4°C) or as cryopreserved shoot tips held in liquid nitrogen (-196°C). The genetic diversity of the collections poses multiple challenges for culture; for example the 200 pear accessions maintained in vitro include 19 species and 154 cultivars. Cryopreservation of shoot tips involves one of three commonly used protocols. Research on optimizing growth media and storage conditions as well as improved cryopreservation protocols is in progress. Many accessions are in long-term storage in liquid nitrogen.