Submitted to: Horticultural Reviews
Publication Type: Review Article
Publication Acceptance Date: 1/1/2003
Publication Date: 3/20/2003
Citation: Volk, G.M. and C. Walters. 2003. Preservation of genetic resources in the national plant germplasm clonal collections. Plant Breeding Reviews 23:291-344. Interpretive Summary: The National Plant Germplasm System's collection of vegetatively propagated plants is large and diverse. Most of the 30,000 accessions are not backed up in a secure facility because the technology to cryogenically store these genetic resources is not yet available. This review is a comprehensive synthesis of the contents in the Collection and outlines the strategy and challenges that are in place to ensure that these important resources are available in perpetuity.
Technical Abstract: The NPGS clonal collection consists of about 30,000 accessions from over 56 genera of crops and over 100 genera used for ornamental purposes. These plants are propagated vegetatively because the species is highly outcrossing, making it difficult to maintain desirable genotypes through sexual reproduction, or the species does not easily produce flowers and seeds. Most of these accessions are maintained in field plots in 25 locations throughout the US. Backing up accessions through cryogenic storage would safeguard these valuable genetic resources. Identifying propagules that can easily be regenerated but tolerate the stresses incurred from cryoexposure is necessary. Technology exists to cryopreserve dormant buds or in vitro shoot tips and efforts are underway to make protocols generally adaptable to a wide range of species.