Fusarium culmorum is an important pathogen within the complex of Fusarium species causing head blight of cereals in Europe. We analyzed 92 isolates sampled from different field populations in Germany, Russia, and Syria together with an international collection for aggressiveness and DON production in replicated field experiments at two locations in two years with two hosts, wheat and rye. 30x coverage whole-genome re-sequencing of all isolates resulted in the identification of 130,389 high quality SNPs that were used for a genome-wide association study. In wheat, 20 and 27 SNPs were detected for aggressiveness and DON content, respectively, of which 10 overlapped. Additionally, two different SNPs were significantly associated with aggressiveness in rye that were among those SNPs being associated with DON production in wheat. Most of the SNPs explained only a small proportion of genotypic variance (pG), however, four SNPs were associated with major QTLs with pG ranging from 12 to 48%. The latter QTL was involved in DON production and associated with a SNP most probably located within the Tri4 gene. As a consequence, a large part of Fusarium aggressiveness in wheat and rye appears to be explained by QTL responsible for DON production.
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