Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/29/2004
Publication Date: 2/1/2005
Citation: Yan, W., Rutger, J.N., Bockelman, H.E., Tai, T. 2005. Evaluation of the core subset of the USDA-ARS rice germplasm collection. Rice Technical Working Group Meeting Proceedings. Abstract p. 52.
Technical Abstract: A core collection is a subset of a large germplasm collection that contains chosen accessions capturing most of the genetic variability of the whole gene bank. The core subset strategy should increase efficiency in germplasm evaluation and management. A rice core subset was established by the stratified randomly sampling method. This core containing 1,686 accessions coming from 106 countries is about 10% of the whole US rice collection of 17,359 accessions. Seed stocks of the core are being prepared and stored in the USDA-ARS, Dale Bumpers National Rice Research Center for a comprehensive evaluation including descriptors in agronomy; morphology; grain quality; pest and stress resistance; and DNA analysis with microsatellite markers for various phenotypic descriptors. Evaluation on agronomic traits including heading, plant height, plant type, panicle type and awn type was conducted in 2002. Data of the core collected from the evaluation and of the whole collection from the current GRIN (Germplasm Resources Information Network) were analyzed for similarity. The analysis concluded that this core subset contained most of the genetic diversity in the whole collection in terms of agronomic traits. As a result, this core can represent the whole rice collection in evaluation and management. Data from all the evaluations will be entered in the GRIN and be available for the public. Then, germplasm curators can use the information to assess the genetic diversity of the existing collection, identify gaps for planning acquisition strategies, and monitor changes in heterogeneity and heterozygosity (genetic drift) as accessions are regenerated. Rice breeders can quickly find useful gene and make a best plan for transferring to commercial cultivar based on the relationship of this gene with other genes in both genotypic and phenotypic level.