'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 CHROMOSOME HAPLOTYPING: A NOVEL APPROACH TO IDENTIFY CHROMOSOMAL REGIONS THAT ARE IDENTICAL BY DESCENT R. MANK, R. VAN WIJK, J.R. VAN DER VOORT, M. VAN DER MEULEN, R. VAN SCHAIK, J. PELEMAN Keygene N.V., Agro Business Park 90, P.O.Box 216, NL-6700 AE Wageningen, The Netherlands

The availability of a highly saturated and integrated genetic map opens new applications in the field of Marker Assisted Breeding. Our integrated genetic map of corn is based on 23 independent mapping populations and contains 5650 markers of which 4533 are generated by AFLP. A set of 30 corn inbred lines was investigated by use of 20 AFLP primer combinations. Out of the 1082 markers generated, 759 (70%) of these markers were also present on the integrated genetic map. A software package was developed to order the marker genotypes of the inbreds according to their map position thereby generating “high resolution” haplotypes of complete chromosomes. Subsequently, common stretches of marker genotypes of variable length were traced in order to identify regions that are presumed to be identical by descent. Visualizing allelic diversity by a genome wide scan provides novel opportunities for various applications in Marker Assisted Breeding like germplasm analysis, evaluating (near isogenic) lines and plant variety protection. AFLP® is a registered trademark of Keygene N.V..