title: Simultaneous transfer, introgression, and genomic localization of genes for resistance to stem rust race TTKSK (Ug99) from Aegilops tauschii to wheat.
abstract: Wheat production is currently threatened by widely virulent races of the wheat stem rust fungus, Puccinia graminis f. sp. tritici, that are part of the TTKSK (also known as 'Ug99') race group. The diploid D genome donor species Aegilops tauschii (2n = 2x = 14, DD) is a readily accessible source of resistance to TTKSK and its derivatives that can be transferred to hexaploid wheat, Triticum aestivum (2n = 6x = 42, AABBDD). To expedite transfer of TTKSK resistance from Ae. tauschii, a direct hybridization approach was undertaken that integrates gene transfer, mapping, and introgression into one process. Direct crossing of Ae. tauschii accessions with an elite wheat breeding line combines the steps of gene transfer and introgression while development of mapping populations during gene transfer enables the identification of closely linked markers. Direct crosses were made using TTKSK-resistant Ae. tauschii accessions TA1662 and PI 603225 as males and a stem rust-susceptible T. aestivum breeding line, KS05HW14, as a female. Embryo rescue enabled recovery of F1 (ABDD) plants that were backcrossed as females to the hexaploid recurrent parent. Stem rust-resistant BC1F1 plants from each Ae. tauschii donor source were used as males to generate BC2F1 mapping populations. Bulked segregant analysis of BC2F1 genotypes was performed using 70 SSR loci distributed across the D genome. Using this approach, stem rust resistance genes from both accessions were located on chromosome arm 1DS and mapped using SSR and EST-STS markers. An allelism test indicated the stem rust resistance gene transferred from PI 603225 is Sr33. Race specificity suggests the stem rust resistance gene transferred from TA1662 is unique and this gene has been temporarily designated SrTA1662. Stem rust resistance genes derived from TA1662 and PI 603225 have been made available with selectable molecular markers in genetic backgrounds suitable for stem rust resistance breeding.
authors: Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA.
authors: Eric L
authors: EL
authors: Olson
authors: Matthew N
authors: MN
authors: Rouse
authors: Michael O
authors: MO
authors: Pumphrey
authors: Robert L
authors: RL
authors: Bowden
authors: Bikram S
authors: BS
authors: Gill
authors: Jesse A
authors: JA
authors: Poland
mesh_terms: D001487:Basidiomycota / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D018744:DNA, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D007113:Immunity, Innate / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018547:Plant Stems / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D014908:Triticum / Q000235:genetics* / Q000276:immunology / Q000382:microbiology
chemical_list: D018744:DNA, Plant
references: Exp Cell Res. 1968 Apr;50(1):151-8
references: 5650857
references: J Hered. 1946 Mar;37:81 107
references: 20985728
references: Chromosome Res. 2011 Jul;19(5):669-82
references: 21728140
references: Theor Appl Genet. 2006 Feb;112(4):618-26
references: 16402192
references: Theor Appl Genet. 2011 Jun;123(1):159-67
references: 21437597
references: Theor Appl Genet. 2011 May;122(8):1537-45
references: 21347655
references: BMC Plant Biol. 2010 Apr 20;10:72
references: 20406451
references: Genetics. 2011 Apr;187(4):1011-21
references: 21242535
references: Theor Appl Genet. 1995 Mar;90(3-4):571-7
references: 24173953
references: Chromosome Res. 2007;15(1):3-19
references: 17295123
references: Genome. 1994 Oct;37(5):813-22
references: 18470124
references: Nat New Biol. 1973 Feb 21;241(112):256
references: 4512486
references: Genome. 2008 May;51(5):341-9
references: 18438437
references: Genomics. 1987 Oct;1(2):174-81
references: 3692487
references: G3 (Bethesda). 2012 Jun;2(6):665-73
references: 22690376
references: Annu Rev Phytopathol. 2011;49:465-81
references: 21568701