Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/5/2005
Publication Date: 4/25/2005
Citation: Yan, W., Rutger, J.N., Bockelman, H.E., Tai, T. 2005. Usda rice core collection and its genetic assessment. In: Proceedings of International Symposium on Genetic-based Plant Germplasm Research, April 25-28, 2005, Beijing, China. p. 9-17.
Technical Abstract: Working with a core collection is a strategy that increases the efficiency of germplasm evaluation and management. The United States Department of Agriculture (USDA) rice core collection is identified in the Germplasm Resources Information Network (GRIN), and was assembled by a stratified random sampling method. This core of 1,794 accessions from 114 countries or sources represents approximately 10% of 17,396 rice accessions in the National Small Grains Collection (NSGC), and is expected to represent over 70% of the total variation in the NSGC collection. China, the Philippines and Japan were ranked the top contributors each with 69 or more sampled entries. From 11 to 30 entries were sampled for 48 countries. Only one entry was sampled from each of 20 countries. Complete or 100% sampling of germplasm in the NSGC collection was made for 37 countries. The cultivated species Oryza sativa is nearly 99% of the core collection, with the remaining accessions representing the other 10 species of Oryza in the NSGC collection. The sampling was made from historical to modern germplasm with a slight emphasis on the modern. Comprehensive evaluations, including phenotyping 28 descriptors and genotyping with 183 markers, are being conducted by a joint effort of federal and state institutions in the United States, and Chinese cooperators. All the results from both phenotyping and genotyping will be displayed in GRIN for the public.