Karyotype characterization of wheat breeding lines carrying resistance genes from Aegilops ventricosa

Abstract

We have used in situ hybridization combining genomic and repeated DNA fluorescent probes to determine the karyotype composition of two bread wheat introgression lines: H-93-33, which carries the gene H27 for resistance to the Hessian fly M. destructor (Delibes et al. 1997); and H-93-8, carrying the gene Cre2 which confers resistance to the cereal cyst nematode H. avenae (Delibes et al. 1993). Both introgression lines had been derived from an earlier cross between T. aestivum subsp. aestivum (2n=42; genome composition AABBDD) and a semi-fertile hybrid between T. turgidum subsp. turgidum (2n=28; genome composition AABB) and the wild grass Ae. ventricosa (2n=28; genome constitution DvDvN¬vNv). We also have examined several resistant advanced lines that were obtained from H-93-33 (lines ID-2151, ID-2193, Ma-1612-a and Ma-1612-b) or H-93-8 (line ID-2150) after 3 to 5 backcrosses with commercial wheats.