Author Description

. Rostochiensis. Resistance to the potato cyst nematodes G. pallida and G. rostochiensis is an important aspect in potato breeding. To gain insight in the structure of the genes underlying nematode resistance, it is necessary to first map nematode resistance loci, as described for the resistance loci Gpa5 and Gpa6. Subsequently, both for map-based cloning and for marker-assisted selection, a high-resolution map of thespan style='mso-bidi-font-style:italic'resistance locus is required. A high-resolution map is produced for the H1 locus. To gain more insight in the genomic organisation of a complex disease resistance locus, Gpa2/Rx1 homologues derived from differentspan class=SpellEhaplotypes have been characterised. Finally, the Gpa2/Rx1 homologues derived from fivespan class=SpellEhaplotypes have been subjected to extensive sequence analysis to elucidate their structural diversity and evolutionary relationships.