The European apple map
Maliepaard, C, Vrielink, R, van Heudsen, S, Verhaegh, J, Janse, J, den Nijs, A, Brown, L, Ryder, C, Periam, N, Lynn, J, King, GJ, Roche, P, Evans, K, Alston, F, Tartarini, S, Sansavini, S, Dunemann, F, Schmidt, H, Chevreau, E, Laurens, F, Manganaris, A, Gardiner, S 1998, in KR Tobutt & FH Alston (eds), Proceedings of the Eucarpia Symposium on Fruit Breeding and Genetics, St. Catherine's College, Oxford, U.K., 1-6 September 1996, Acta horticulturae; no. 484, International Society for Horticultural Science, Leuven, Belgium, pp. 519-522.
In the European Apple Genome Mapping project a linkage map of apple was generated in a ‘Prima’ x ‘Fiesta’ progeny. Some 155 F1 seedlings were genotyped, using 208 markers - RFLPs, RAPDs, isoenzymes and microsatellites. Markers heterozygous in ‘Prima’ could be assigned to 17 linkage groups, markers heterozygous in ‘Fiesta’ to 19 linkage groups. Markers heterozygous in both parents allowed the identification of 17 homologous pairs. Skewed segregation was observed for 14 marker loci mainly at two regions of the genome. Recombination frequencies were usually higher in ‘Fiesta’ than in ‘Prima’. RFLP results indicated a large number of duplicate loci in the apple genome and provided evidence for at least three duplicated regions. Map positions of the Vf gene for scab resistance, the Sd1 gene for resistance to rosy leaf curling aphid and the S locus for self-incompatibility were determined in this cross.