Breeding for resistance to Fusarium head blight (FHB) in durum wheat continues to be hindered by the lack of effective resistance sources. Only limited information is available on resistance QTL for FHB in tetraploid wheat. In this study, resistance to FHB of a Triticum dicoccum line in the background of three Austrian T. durum cultivars was genetically characterized. Three populations of BC1F4-derived RILs were developed from crosses between the resistant donor line T. dicoccum-161 and the Austrian T. durum recipient varieties DS-131621, Floradur and Helidur. About 130 BC1F4-derived lines per population were evaluated for FHB response using artificial spray inoculation in four field experiments during two seasons. Lines were genetically fingerprinted using SSR and AFLP markers. Genomic regions on chromosomes 3B, 4B, 6A, 6B and 7B were significantly associated with FHB severity. FHB resistance QTL on 6B and 7B were identified in two populations and a resistance QTL on 4B appeared in three populations. The alleles that enhanced FHB resistance were derived from the T. dicoccum parent, except for the QTL on chromosome 3B. All QTL except the QTL on 6A mapped to genomic regions where QTL for FHB have previously been reported in hexaploid wheat. QTL on 3B and 6B coincided with Fhb1 and Fhb2, respectively. This implies that tetraploid and hexaploid wheat share common genomic regions associated with FHB resistance. QTL for FHB resistance on 4B co-located with a major QTL for plant height and mapped at the position of the Rht-B1 gene, while QTL on 7B overlapped with QTL for flowering time.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-012-1951-2) contains supplementary material, which is available to authorized users.

An international winter wheat assortment was evaluated for resistance to T. caries and T. controversa under organic farming conditions. 98 genotypes were screened for resistance to T. caries and 29 genotypes for resistance to T. controversa by artificial inoculation during one season. A set of differential cultivars was included for testing virulence/avirulence against particular resistant genes. For T. caries no disease symptoms were observed for 9 genotypes, 25 genotypes showed low infection (0.1%-1% infection) and 14 genotypes were highly susceptible (40.5%-70.6% diseased spikes). Screening for resistance to T. controversa resulted in only 1 resistant genotype (0.0% infection), one genotype showed low infection (0.5% diseased spikes) and 11 genotypes were highly susceptible (39.0%-85.3% infection). Resistance genes Bt12 and Bt13 conferred resistance to both species: T. caries and T. controversa.

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