Development of a set of Triticum aestivum-Aegilops tauschii introgression lines.

New wheat introgression lines were obtained which contain different segments of individual chromosomes of Aegilops tauschii in the Triticum aestivum cv. 'Chinese Spring' background. The introgression lines were developed to examine various subsets of alleles from the wild grass in the genetic background of common wheat. As starting point substitution lines of 'Chinese Spring' in which single chromosomes of the D genome had been replaced by homologous chromosomes of a synthetic wheat were used. Synthetic wheat had been obtained earlier from a cross between the tetraploid emmer (genomes AABB) and wild grass Aegilops tauschii (genome DD). The seven wheat chromosome substitution lines carrying different chromosomes of Ae. tauschii were crossed twice to T. aestivum cv. 'Chinese Spring' and 259 BC1-progeny plants were analysed. Phenotypic evaluation was carried out for different traits such as plant height, spikelet number, peduncle length, flowering time, spike length, tiller number, grain weight per ear, fertility and thousand kernel weight. Genotypic analysis was performed using a set of 65 microsatellite markers previously mapped on the chromosomes of the D genome of wheat. During this analysis recombinant lines carrying different segments of Ae. tauschii chromosomes were detected. Plants containing small introgressions of the alien genetic material were selfed to get homozygous lines and plants carrying large pieces of the donor chromosome were backcrossed again to get smaller introgressions. Further microsatellite analysis of selected BC1F2-progeny plants resulted in detection of a first set of 36 homozygous lines carrying different pieces of Ae. tauschii genome.