| The main goals of this project are: 1) to construct an ultra-high density linkage map (UHD-map) of potato comprising more than 16,000 markers. This will serve multiple purposes ranging from the dissection of simple and complex phenotypes (including quantitative trait loci (QTLs), marker assisted breeding to positional gene cloning. Detailed marker information will be made available to the 'world community' via World Wide WEb (WWW). Because of the conserved linkage order and small sequence divergence, the potato map will also be highly informative for other Solanaceous crop species, like tomato and pepper. 2) to exploit the ultra-high density genetic map. Here, seven potato genotypes expressing high levels of quantitative resistance to potato cyst nematodes (PCN) will be analysed by QTL of specially constructed segregating populations. Dissection of these resistant phenotypes into their single genetic components will allow the identification of a set of genes conferring durable and broad spectrum resistance against potato cyst nematoed populations in Europe. Tightly linked molecular markers will be converted into allele-specific PCR-based markers, which can be used for marker assisted breeding. To demonstrate the utility of the UHD-map at least one PCN resistance gene will be isolated. |