Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/23/2004
Publication Date: 1/10/2004
Citation: Xingyou, G., Kianian, S., Foley, M.E. 2004. Multiple loci and epistases control genetic variation for seed dormancy in weedy rice (oryza sativa). Abstract. The International Conference on the Status of Plant & Animal Genome Research. January 10-14, 2004. P. 385
Technical Abstract: Xing-You Gu', Shahryar Kianian', and Michael E. Foley '1 'Department of Plant Sciences, North Dakota State University, Fargo, ND 58105 'Biosciences Research Laboratory, USDA-Agricultural Research Service, Fargo, ND 58105 ABSTRACT Weedy rice has much stronger seed dormancy than cultivated rice. A wild-like weedy strain SS18-2 was selected to investigate the genetic architecture underlying seed dormancy, a critical adaptive trait in plants. A framework genetic map covering the whole rice genome was constructed based on 156 BC1 [EM93-1(non-dormant breeding line)//EM93-1/SS18-2] individuals. The mapping population was replicated using a split-tiller technique to control and better estimate the environmental variation. Dormancy was determined by germination of seeds after 1, 11, and 21 days of after-ripening (DAR). Six dormancy QTLs, designated as qSDS-4, -6, -7-1, -7-2, -8, and -12, were identified. The locus qSDS-7-1 was tightly linked to the red pericarp color gene Rc. A QTL×DAR interaction was detected for qSDS-12, the locus with the largest main effect at 1, 11, and 21 DAR (R2 = 0.14, 0.24, and 0.20, respectively). Two and higher (three and four) orders of epistases were detected with 4 and all of the 6 QTL, respectively. The higher-order epistases strongly suggests the presence of genetically complex networks in the regulation of variation for seed dormancy in natural populations, and makes it critical to select for a favorable combination of alleles at multiple loci in positional cloning of a target dormancy gene.