Resistance in oats (Avena sativa L.) to Fusarium graminearum was phenotyped in 424 spring oat lines from North America and Scandinavia and genotyped with 2974 SNP markers. Fusarium head blight (FHB), deoxynivalenol (DON) content, days to flowering (DTF) and days to yellow maturity (DTM) were scored in field trials in 2011–12. Trials with phenotypic ranges from 1 to 30 ppm, and sufficient accuracy were obtained by an augmented design and spawn inoculation. Discriminant analysis–PCA identified the different gene pools, with overlaps corresponding to known pedigrees and germplasm exchanges. Structure was negligible and GWAS (genomewide association study) was done using mixed linear models in TASSEL or partial least-squares regression (PLSR). PLSR allows simultaneous analyses of several phenotypes (environments and/or traits) and is a promising tool for GWAS in plants and should be tested in species with sequenced genomes. FHB was associated with phenology QTLs, due to very susceptible early lines from the Midwest. Lines with consistently low DON (and early heading) were identified. Six QTLs for DON were not associated with earliness, including three QTLs reported previously.
Bibliographical noteFunding Information:
The authors acknowledge the generous support for this project from: the Norwegian Research Council Project 199412 (2010–2013) Mycotoxin contamination in Norw. food and feed - modelling, reductive approaches and risk assessment with regard to the whole food chain (field and analytical experimental costs); Graminor AS, responsible for oat breeding in Norway, for support to the mentioned project and the long-term collaboration on Fusarium testing; the Collaborative Oat Research Enterprise by General Mills, the North American Millers Association, the Prairie Oat Growers Association of Canada, USDA-NIFA, and Agriculture and Agri-food Canada, Eric Jackson, for his vision and leadership of the CORE (multiplication of accessions, production and editing of marker data). We refer the reader to the public T3/Oat database (https://triticeaetoolbox.org/oat) where more data and related metadata for markers may be downloaded than in the Supplementary File 1, The first author (©AB) wishes to thank Dr. Harald Martens for decades of stimulating discussions about multivariate methods in genetics.
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