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Fusarium head blight (FHB) caused byFusarium species, is among the most devastating wheat diseases, causing losses in numerous sectors of the grain industry through yield and quality reduction, and the accumulation of poisonous mycotoxins. A germplasm collection of spring and winter wheat, including nine reference cultivars, was tested for Type II FHB resistance and deoxynivalenol (DON) content. Genetic diversity was evaluated on the basis of Simple Sequence Repeat (SSR) markers linked to FHB resistance quantitative trait loci (QTLs) and Diversity Arrays Technology (DArT) markers. The allele size of the SSR markers linked to FHB resistance QTLs from known resistance sources was compared to a germplasm collection to determine the presence of these QTLs and to identify potentially novel sources of resistance. Forty-two accessions were identified as resistant or moderately resistant to Fusarium spread, and two also had very low DON concentrations. Genetic relationships among wheat accessions were generally consistent with their geographic distribution and pedigree. SSR analysis revealed that several resistant accessions carried up to four of the tested QTLs. Resistant and moderately resistant lines without any known QTLs are considered to be novel sources of resistance that could be used for further genetic studies.

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Our investigation of 460 true-breeding lines confirms a long-standing observation that natural phenotypic and genetic variability in the diploid wheat Triticum monococcum L. is limited. The modes of inheritance of 12 morphological characters are discussed in light of the extensive information available on the genetics and cytogenetics of many of these characters in the related wheat Triticum aestivum. Analysis of data from appropriate crosses, complementation studies, and observations of phenotypes of F1s and F2s from crosses between lines expressing dominant traits indicate that each of these characters is determined by one major gene. A multiple allelic series exists at each of the Hg (glume pubescence) and Hn (node pubescence) loci. The genes for six of these characters fall into two closely linked groups. Genes Bg (glume colour) and Hg are the same distance apart as in Triticum aestivum, indicating that at least this segment of chromosome 1A has been highly or completely conserved since the origin of the polyploid wheats. The genes Sg (glume hardness), La (lemma awn length), Fg (false glume), and Lh (head type) are also very closely linked, with the outside markers being only 4 map units apart. The dominant and recessive alleles of genes determining these characters should serve as excellent markers for linkage and chromosomal mapping because of their complete penetrance and constant expressivity. Tentative assignments of genes and linkage groups identified in this investigation to specific chromosomes of T. monococcum have been made on the basis of known chromosomal locations of A genome genes in T. aestivum. The tentative assignments could be verified using a variety of genetic and cytogenetic approaches. It is suggested that a thorough study of the genetic heritage of einkorn wheat will require the use of induced mutants since natural genetic variability is low in this species.Key words: Triticum, characters, inheritance, linkage, mapping, A genome.