title: Mapping resistance genes for Oculimacula acuformis in Aegilops longissima.
abstract: This study identified three QTL conferring resistance to Oculimacula acuformis in Aegilops longissima and their associated markers, which can be useful in marker-assisted selection breeding for eyespot resistance. Oculimacula acuformis is one of two species of soilborne fungi that cause eyespot of wheat, the other being Oculimacula yallundae. Both pathogens can coexist in the same field and produce elliptical lesions on stem bases of wheat that are indistinguishable. Pch1 and Pch2 are the only two eyespot resistance genes readily available to wheat breeders, but neither provides complete control. A new source of eyespot resistance was identified from Aegilops longissima (2n = 14, S(l)S(l)), a wild relative of wheat. Three QTL for resistance to O. acuformis were mapped in chromosomes 1S(l), 3S(l), and 5S(l) using a recombinant inbred line population developed from the cross Ae. longissima accessions PI 542196 (R) × PI 330486 (S). The three QTL explained 66 % of phenotypic variation by β-glucuronidase score (GUS) and 84 % by visual rating. These QTL had LOD values of 10.6, 8.8, and 6.0 for GUS score, and 16.0, 10.0, and 13.0 for visual rating. QTL associated with resistance to O. acuformis have similar chromosomal locations as some for resistance to O. yallundae, except that a QTL for resistance to O. yallundae was found in chromosome 7S(l) but not for O. acuformis. Thus, it appears that some genes at the same locus in Ae. longissima may control resistance to both eyespot pathogens. QTL effective against both pathogens will be most useful for breeding programs and have potential to improve the effectiveness and genetic diversity of eyespot resistance.
authors.affiliation: Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Sheng
authors.forename: Deven R
authors.initials: DR
authors.lastname: See
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Murray
mesh_terms: D001203:Ascomycota; D002874:Chromosome Mapping; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D006109:Poaceae / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci
references.citation: Genome. 1993 Aug;36(4):731-42
references.pmid: 18470020
references.citation: Annu Rev Phytopathol. 1995;33:429-43
references.pmid: 18999968
references.citation: Theor Appl Genet. 2011 Jan;122(1):119-28
references.pmid: 20703870
references.citation: Theor Appl Genet. 2004 Jul;109(2):323-32
references.pmid: 15014875
references.citation: Theor Appl Genet. 2003 Apr;106(6):961-70
references.pmid: 12671743
references.citation: Theor Appl Genet. 2004 Oct;109(6):1105-14
references.pmid: 15490101
references.citation: Genome. 1997 Apr;40(2):249-52
references.pmid: 18464824
references.citation: Theor Appl Genet. 2011 May;122(7):1339-49
references.pmid: 21258997
references.citation: Theor Appl Genet. 2012 Jul;125(2):355-66
references.pmid: 22406981