Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2005
Publication Date: November 4, 2005
Citation: Pederson, G.A., Erpelding, J.E. 2005. Preserving large germplasm collections: u.s. sorghum collection. In: Proceedings of the ASA-CSSA-SSSA Annual Meeting, November 6-10, 2005, Salt Lake City, UT. 2005 CDROM. Technical Abstract: The U.S. sorghum collection is the second largest collection in the National Plant Germplasm System, comprising over 9% of all U.S. genetic resources. A total of 32,305 accessions are maintained by the USDA, ARS, Plant Genetic Resources Conservation Unit, Griffin, GA, in cooperation wit the S-009 Multistate Regional Project. An additional 10,183 accessions are maintained at Ft. Collins, CO. In 2001, an assessment suggested that up to 10,000 sorghum accessions were in immediate need of regeneration. Others suggested an immediate reduction in size of this large collection; however, the sorghum research community supported preservation of all accessions. Large germplasm collections can be preserved by understanding the actual problems, identifying solutions, and taking action. The following steps were taken to properly preserve this collection. Using passport data from a sweet sorghum collection, duplicate sorghum accessions were identified and linked to reduce collection size. Germination testing was initiated to accurately determine seed quality. Seed quantity of each accession was determined by seed inventory. Security was improved as over 96% of all sorghum accessions were backed up at a second location. Seed regenerations were prioritized to prevent the loss of accessions and to produce adequate seed quality and quantity of all sorghum accessions. Since 2001, over 6,100 sorghum accessions have been regenerated by the Germplasm Introduction and Research Unit, St. Croix. Seed longevity was improved and regeneration frequency was reduced by preserving sorghum accessions in -18 C rather than 4 C, with over 54% of sorghum accessions preserved in -18 C. Customer satisfaction was improved by identifying sorghum accessions with photoperiod insensitivity (Sorghum Crop Germplasm Committee tests) and promptly providing seed of over 90,000 accessions in the last five years to the sorghum industry upon request. The U.S. Sorghum collection is now a model for other large germplasm collections to follow.