'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 PHYSICAL AND GENETIC MAPPING OF TRANSGENICS IN BARLEY L. BILHA, W. HARWOOD, H. SALVO, S. TRAVELLA, J. HARDEN, L. FISH, J. SNAPE John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, England

The most important part of the transformation process over which we have no control at present is the site of transgene integration.  We are working to address this by developing and applying methodologies to determine the physical and genetic location of transgenes.  Fluorescent in situ hybridisation (FISH) is being used to locate transgenic DNA in barley by hybridisation of a labelled DNA probe made up from the introduced plasmid, to transgene DNA are used to give distinct and specific chromosomal patterns to unambiguously identify the individual barley chromosomes.  FISH locations also serve as the starting point for fine interchromosomal genetic mapping using RFLP and SSR molecular markers to accurately determine the genomic map location of the introduced DNA.  We have determined the physical locations of transgenes in fourteen independent transgenic barley lines, and genetic mapping has confirmed the genomic location of the transgene in eight of these lines.  Previous reports state that transgene location appears to be random.  However, our results suggest that in barley there may be some bias using biolistic transformation since transgene.