title: QTL Analysis for Resistance to Blast Disease in U.S. Weedy Rice.
abstract: Understanding the genetic architecture of adaptation is of great importance in evolutionary biology. U.S. weedy rice is well adapted to the local conditions in U.S. rice fields. Rice blast disease is one of the most destructive diseases of cultivated rice worldwide. However, information about resistance to blast in weedy rice is limited. Here, we evaluated the disease reactions of 60 U.S. weedy rice accessions with 14 blast races, and investigated the quantitative trait loci (QTL) associated with blast resistance in two major ecotypes of U.S. weedy rice. Our results revealed that U.S. weedy rice exhibited a broad resistance spectrum. Using genotyping by sequencing, we identified 28 resistance QTL in two U.S. weedy rice ecotypes. The resistance QTL with relatively large and small effects suggest that U.S. weedy rice groups have adapted to blast disease using two methods, both major resistance (R) genes and QTL. Three genomic loci shared by some of the resistance QTL indicated that these loci may contribute to no-race-specific resistance in weedy rice. Comparing with known blast disease R genes, we found that the R genes at these resistance QTL are novel, suggesting that U.S. weedy rice is a potential source of novel blast R genes for resistant breeding.
authors.affiliation: 1 Rice Research and Extension Center, University of Arkansas, Stuttgart 72160, U.S.A.;|2 United States Department of Agriculture-Agricultural Research Service Dale Bumpers National Rice Research Center, Stuttgart, AR 72160, U.S.A.;
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: 3 Department of Biology, Washington University in St. Louis, St. Louis 63130-4899, U.S.A.; and.
authors.forename: Xinshuai
authors.initials: X
authors.lastname: Qi
authors.affiliation: 2 United States Department of Agriculture-Agricultural Research Service Dale Bumpers National Rice Research Center, Stuttgart, AR 72160, U.S.A.;
authors.forename: Dave R
authors.initials: DR
authors.lastname: Gealy
authors.affiliation: 3 Department of Biology, Washington University in St. Louis, St. Louis 63130-4899, U.S.A.; and.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Olsen
authors.affiliation: 4 Biology Department, University of Massachusetts Amherst, 01003, U.S.A.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Caicedo
authors.affiliation: 2 United States Department of Agriculture-Agricultural Research Service Dale Bumpers National Rice Research Center, Stuttgart, AR 72160, U.S.A.;
authors.forename: Yulin
authors.initials: Y
authors.lastname: Jia
mesh_terms: D018556:Crops, Agricultural; D060146:Ecotype; D017343:Genes, Plant; D012275:Oryza / Q000235:genetics* / Q000382:microbiology*; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D057685:Plant Weeds; D040641:Quantitative Trait Loci; D014481:United States