Genome-wide association mapping of tan spot resistance (Pyrenophora tritici-repentis) in European winter wheat

Genome-wide association mapping revealed the genetic architecture of resistance to tan spot caused by Pyrenophora tritici-repentis in a population of 358 European winter wheat varieties and 14 spring wheat varieties (Triticum aestivum L.). Based on field data in two environments and the resulting best linear estimations, a total of 90 marker–trait associations were significant with −log10(P) > 3.0 by using a mixed linear model corrected with a kinship matrix. While the inheritance pattern of resistance to tan spot appeared to be quantitative, a number of already-known resistance or susceptibility loci were confirmed, such as Tsn1 on chromosome 5B, tsn2 or tsn5 on chromosome 3B and Tsc2 or Tsr6 on chromosome 2B. Additionally, evidence for novel loci was gathered. Additive effects of favourable or unfavourable alleles were observed and suggest the application of genomic selection as a possible strategy for further variety development.