Cytogenetic and molecular identification of three Triticum aestivum-Leymus racemosus translocation addition lines

Chromosome 2C fromAegilops cylindrica has the ability to induce chromosome breakage in common wheat (Tritivum aestivum). In the BC1F3 generation of the T. aestivum cv. Chinese Spring and a hybrid between T. aestivum-Leymus racemosus Lr.7 addition line and T.aestivum-Ae. cylindrica 2C addition line, three disomic translocation addition lines (2n = 44) were selected by mitotic chromosome C-banding and genomic in situ hybridization. We further characterized these T. aestivum-L. racemosus translocation addition lines,NAU636, NAU637 and NAU638, by chromosome C-banding, in situ hybridization using the A-and D-genome-specific bacterial artificial chromosome (BAC) clones 6761D4 and 9M13; plasmids pAsl and pSc119.2, and 45S rDNA; as well as genomic DNA of L. racemosus as probes, in combination with double ditelosomic test cross and SSR marker analysis. The translocation chromosomes were designated as T3AS-Lr7S, T6BS-Lr7S, and T5DS-Lr7L. The translocation line T3AS-Lr7S was highly resistant to Fusarium head blight and will be useful germplasm for resistance breeding.