Submitted to: Pisum Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/8/2005
Publication Date: 12/30/2005
Citation: Coyne, C.J., Brown, A., Timmerman-Vaughan, G.M., Mcphee, K.E., Grusak, M.A. 2005. Refined usda-ars pea core collection based on 26 quantitative traits. Pisum Genetics. 37:3-6. Interpretive Summary: Creation of core subsets of crop germplasm collections was first suggested by Frankel as a way to efficiently utilize plant germplasm collections. The purpose of this study was to reduce the size of the USDA pea core to 10% of the Pisum accessions and to reduce trait redundancy without reducing the trait diversity. The traits selected were based on economically important characters of pea for which data was available for a significant portion of the USDA pea core collection. The refined core will be used for replicated field experiments and laboratory molecular studies of economically useful allelic diversity in the collection and to identify significant gaps in the core. This baseline information on the refined pea core may contribute to association mapping (linkage disequilibrium) studies in Pisum.
Technical Abstract: The purpose of this study was to investigate any redundancy in the USDA pea core based on a diverse set of quantitative data and to use the relationships discovered to refine the core for future allelic diversity studies on economic traits of pea. An underlying assumption was that a core of 504 (14.4%) selected in 1995 from the approximately 3,500 pea accessions in the collection at that time would over-represent the collection. Additionally, 500 of the 3500 accessions are Marx Genetic Stocks created by backcrossing to the same parent, so the core is closer to 16.8% of the 1995 collection. By reducing the size of the core to 10% of the Pisum accessions held in 1995, trait redundancy may be reduced without reducing the trait diversity. The 310 accessions included in the reduced core collection are a subset of the 504 accessions included in the reduced core collection. Comparison of means and variances indicates no significant loss of genetic variation for 26 traits between the original and the refined core. The dendogram of the refined USDA core collection can be found at http://www.ars-grin.gov/npgs/ under the descriptor REFINED CORE.