The eyespot resistance genes Pch1 and Pch2 of wheat are not homoeoloci.
Phenotyping and mapping data reveal that chromosome intervals containing eyespot resistance genes Pch1 and Pch2 on 7D and 7A, respectively, do not overlap, and thus, these genes are not homoeloci. Eyespot is a stem-base fungal disease of cereals growing in temperate regions. Two main resistances are currently available for use in wheat. Pch1 is a potent single major gene transferred to wheat from Aegilops ventricosa and located on the distal end of chromosome 7D. Pch2, a moderate resistance deriving from Cappelle Desprez, is located at the end of 7AL. The relative positions of Pch1 and Pch2 on 7D and 7A, respectively, suggest that they are homoeoloci. A single seed decent recombinant F7 population was used to refine the position of Pch2 on 7A. New markers designed to 7D also allowed the position of Pch1 to be further defined. We exploited the syntenic relationship between Brachypodium distachyon and wheat to develop 7A and 7D specific KASP markers tagging inter-varietal and interspecific SNPs and allow the comparison of the relative positions of Pch1 and Pch2 on 7D and 7A. Together, phenotyping and mapping data reveal that the intervals containing Pch1 and Pch2 do not overlap, and thus, they cannot be considered homoeloci. Using this information, we analysed two durum wheat lines carrying Pch1 on 7A to determine whether the Ae.ventricosa introgression extended into the region associated with Pch2. This identified that the introgression is distal to Pch2 on 7A, providing further evidence that the genes are not homoeoloci. However, it is feasible to use this material to pyramid Pch1 and Pch2 on 7A in a tetraploid background and also to increase the copy number of Pch1 in combination with Pch2 in a hexaploid background.
John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
M
M
Pasquariello
John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
J
J
Ham
RAGT Seeds, Grange Road, Ickleton, Essex, CB10 1TA, UK.
C
C
Burt
IGEPP, Institute for Genetics, Environment and Plant Protection, INRA, La Motte au Vicomte, 35650, Le Rheu, France.
J
J
Jahier
IGEPP, Institute for Genetics, Environment and Plant Protection, INRA, La Motte au Vicomte, 35650, Le Rheu, France.
S
S
Paillard
John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
C
C
Uauy
John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK. paul.nicholson@jic.ac.uk.
P
P
Nicholson
D001203:Ascomycota; D058431:Brachypodium / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D005819:Genetic Markers; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D026801:Synteny; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
D005819:Genetic Markers
Genome. 1997 Apr;40(2):249-52
18464824
Plant J. 2014 Dec;80(5):895-904
25205592
Heredity (Edinb). 2005 Sep;95(3):221-7
16077740
Science. 2009 Mar 6;323(5919):1360-3
19229000
Anal Biochem. 1991 Jul;196(1):80-3
1716076
Science. 2013 Aug 16;341(6147):786-8
23811228
PLoS One. 2014 Apr 09;9(4):e94171
24718312
Theor Appl Genet. 2011 Dec;123(8):1387-400
21833553
Theor Appl Genet. 1992 May;83(8):1044-7
24202933
Proc Natl Acad Sci U S A. 2003 Dec 9;100(25):15253-8
14645721
Nature. 2010 Feb 11;463(7282):763-8
20148030
Theor Appl Genet. 2008 Jan;116(2):261-70
17952400
Genome. 2001 Jun;44(3):345-9
11444692
Theor Appl Genet. 2011 Jan;122(1):119-28
20703870
Theor Appl Genet. 2008 Aug;117(3):425-33
18483719
Genetics. 2011 Apr;187(4):1011-21
21242535
Theor Appl Genet. 2009 Apr;118(6):1045-57
19183860
Plant Biotechnol J. 2014 Aug;12(6):787-96
24646323
Bioinformatics. 2015 Jun 15;31(12):2038-9
25649618
Proc Natl Acad Sci U S A. 2006 Dec 19;103(51):19581-6
17158798
Plant Cell. 2014 Apr 11;26(4):1382-1397
24728647
Theor Appl Genet. 1986 Sep;72(6):743-7
24248194