1Institute for Plant Production Biotechnology, and 2Center for Analytical Chemistry, Department IFA-Tulln, BOKU-University of Natural Resources and Applied Life Sciences, Konrad Lorenzstr. 20, A-3430 Tulln, Austria; 3Institute of Applied Genetics and Cell Biology, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190, Vienna, Austria; 4Laboratory of Plant Pathology, Wheat Breeding Department, Cereal Research non-profit Co., Alsókikötösor 9, 6701, Szeged, Hungary
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Accepted 15 August 2005.
We investigated the hypothesis that resistance to deoxynivalenol (DON) is a major resistance factor in the Fusarium head blight (FHB) resistance complex of wheat. Ninety-six double haploid lines from a cross between ‘CM-82036’ and ‘Remus’ were examined. The lines were tested for DON resistance after application of the toxin in the ear, and for resistances to initial infection and spread of FHB after artificial inoculation with Fusarium spp. Toxin application to flowering ears induced typical FHB symptoms. Quantitative trait locus (QTL) analyses detected one locus with a major effect on DON resistance (logarithm of odds = 53.1, R2 = 92.6). The DON resistance phenotype was closely associated with an important FHB resistance QTL, Qfhs.ndsu-3BS, which previously was identified as governing resistance to spread of symptoms in the ear. Resistance to the toxin was correlated with resistance to spread of FHB (r = 0.74, P < 0.001). In resistant wheat lines, the applied toxin was converted to DON-3-O-glucoside as the detoxification product. There was a close relation between the DON-3-glucoside/DON ratio and DON resistance in the toxintreated ears (R2 = 0.84). We conclude that resistance to DON is important in the FHB resistance complex and hypothesize that Qfhs.ndsu-3BS either encodes a DON-glucosyltransferase or regulates the expression of such an enzyme.
© 2005 The American Phytopathological Society