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With 2 figures and 3 tables RE714 is a winter wheat breeding line obtained from two interspecific crosses [( Aegilops tauschii no. 33/ Triticum dicoccum no. 119) and VPM = ( Aegilops ventricosa no. 10/ T. persicum)///Marne]. RE714 expresses powdery mildew resistance at the seedling, vernalized and adult stages. The origin of the main genetic factors involved in RE714 powdery mildew resistance ( Pm4b, QPm.inra-5D, QPm.inra-6A2, QPm.inra-7A3a and QPm.inra-7A3b) was studied by comparing alleles of RE714 and those of seven of its parental lines with 36 microsatellite markers previously detected as linked to these factors. VPM, and among its parental lines, the T. persicum accession, were identified as the donor of Pm4b to RE714. Aegilops tauschii no. 33 and T. dicoccum no. 119 were identified as the donors of QPm.inra-5D and QPm.inra-6A2 to RE714, respectively. Beauchamp, a line used at the end of the breeding scheme that created RE714, might be the donor of the favourable alleles of RE714 at quantitative trait loci on linkage group 7A3. These results are discussed in the context of introgression of valuable genetic factors from related species of the primary gene pool into wheat. [ABSTRACT FROM AUTHOR]

Abstract Moderate resistance to eyespot was first incorporated in the variety Cappelle-Desprez (CD). Later the gene Pch1 , which could confer a higher level of resistance, was introduced from Aegilops ventricosa . However Pch1 -carrying varieties can sustain significant eyespot-induced yield losses in severe attack situations. A strategy to further enhance the resistance of wheat is by pyramiding Pch1 and the genes for resistance in CD. The first requirement to achieve this is a better understanding of the genetics of resistance in CD. The resistance of the 21 Cappelle-Desprez (Bezostaya) disomic substitution lines was evaluated. Chromosome 7A was confirmed as carrying a major gene for resistance to eyespot at the seedling stage. However, this study demonstrates that this chromosome has no effects at the adult stage. Chromosome 5A was shown to carry a major gene for resistance to eyespot at the adult stage, which was stably expressed each year of testing. Chromosomes 1A and 2B had significant effects for only two years among four. [ABSTRACT FROM AUTHOR]