Genome-wide association mapping of resistance to eyespot disease (Pseudocercosporella herpotrichoides) in European winter wheat (Triticum aestivum L.) and fine-mapping of Pch1
- 1k Downloads
Genotypes with recombination events in the Triticum ventricosum introgression on chromosome 7D allowed to fine-map resistance gene Pch1, the main source of eyespot resistance in European winter wheat cultivars.
Eyespot (also called Strawbreaker) is a common and serious fungal disease of winter wheat caused by the necrotrophic fungi Oculimacula yallundae and Oculimacula acuformis (former name Pseudocercosporella herpotrichoides). A genome-wide association study (GWAS) for eyespot was performed with 732 microsatellite markers (SSR) and 7761 mapped SNP markers derived from the 90 K iSELECT wheat array using a panel of 168 European winter wheat varieties as well as three spring wheat varieties and phenotypic evaluation of eyespot in field tests in three environments. Best linear unbiased estimations (BLUEs) were calculated across all trials and ranged from 1.20 (most resistant) to 5.73 (most susceptible) with an average value of 4.24 and a heritability of H 2 = 0.91. A total of 108 SSR and 235 SNP marker–trait associations (MTAs) were identified by considering associations with a −log10 (P value) ≥3.0. Significant MTAs for eyespot-score BLUEs were found on chromosomes 1D, 2A, 2D, 3D, 5A, 5D, 6A, 7A and 7D for the SSR markers and chromosomes 1B, 2A, 2B, 2D, 3B and 7D for the SNP markers. For 18 varieties (10.5%), a highly resistant phenotype was detected that was linked to the presence of the resistance gene Pch1 on chromosome 7D. The identification of genotypes with recombination events in the introgressed genomic segment from Triticum ventricosum harboring the Pch1 resistance gene on chromosome 7DL allowed the fine-mapping of this gene using additional SNP markers and a potential candidate gene Traes_7DL_973A33763 coding for a CC-NBS-LRR class protein was identified.
KeywordsWheat Variety Winter Wheat Variety Spring Wheat Variety European Winter Wheat Eyespot Resistance
This research was funded by the Plant Biotechnology program of the German Federal Ministry of Education and Research (BMBF) within the frame of the projects GABI-Wheat, VALID and SELECT (Project Numbers 0315067, 0315947 and 0315949).
Compliance with ethical standards
Conflict of interest
SK, VK and EE are employed by the company KWS LOCHOW GMBH, OA is employed by Syngenta France S.A.S., GS and TZ are employed by Syngenta Seeds GmbH and MG, JP and AP are employed by the company TraitGenetics GmbH. The companies have commercial interest in the results for application in variety development and for the provision of genotyping services. This does not alter the authors’ adherence to all TAG policies on sharing data and materials. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Bartels G, Backhaus GF (2000) Testing of crop cultivars for resistance to noxious organisms at the Federal Biological Research Centre. Mitteilungen aus der Biologischen Bundesanstalt für Land- und Forstwirtschaft, Berlin-Dahlem, Heft 373:24–27Google Scholar
- Leonard JM, Watson CJW, Carter AH, Hansen JL, Zemetra RS, Santra DK, Campbell KG, Riera-Lizarazu O (2008) Identification of candidate gene for the wheat endopeptidase Ep-D1 locus and two other STS markers linked to the eyespot resistance gene Pch1. Theor Appl Genet 116:261–270CrossRefPubMedGoogle Scholar
- McMillian DE, Allan RE, Roberts DE (1986) Association of an isozyme locus and strawbreaker foot rot resistance derived from Aegilops ventricosa in wheat. Theor Appl Genet 72:743–747Google Scholar
- The International Wheat Genome Consortium (IWGSC) (2014) A chromosome-based draft sequence of the hexaploid wheat (Triticum aestivum) genome. Science 345Google Scholar
- Zanke C, Ling J, Plieske J, Kollers S, Ebmeyer E, Korzun V, Argillie O, Stiewe G, Hinze M, Neumann F, Eichhorn A, Polley A, Jaenecke C, Ganal MW, Röder MS (2015) Analysis of main effect QTL for thousand grain weight in European winter wheat (Triticum aestivum L.) by genome-wide association mapping. Frontiers. Plant Sci 6:644Google Scholar