Locating introgressions of Hordeum bulbosum chromatin within the H-vulgaregenome

Several disease-resistant recombinants between barley (Hordeum vulgare) and bulbous barley grass (H. bulbosum) have been obtained in recent years, but the process of characterization is often laborious and time-consuming. In order to improve the identification and chromosomal location of introgresse d chromatin from H, bulbosum into the barley genome, we employed sequential genomic in situ hybridization (GISH) and fluorescence in situ hybridizatio n (FISH). GISH enabled us to establish that an introgression was present in the disease-resistant recombinant line, and the subsequent use of FISH, wi th a short oligonucleotide sequence as probe, allowed us to locate the intr ogression on the long arm of barley chromosome 2H. These data were confirme d using RFLP probes that hybridize to barley chromosome 2HL.