Narrowing down the region of the Vf locus for scab resistance in apple using AFLP-derived SCARs.
A narrow-down strategy to restrict the Vf region, which controls resistance to the fungal disease apple scab in apple, to a genetic distance of 0.4 cM is presented. Using 11 AFLP-derived SCARs and three RAPD-derived SCARs, all linked to the Vf gene, we subjected 1,412 scab-resistant individuals from 16 mapping populations to genotype analysis. Eleven recombinant individuals were identified within a genetic distance of 0.9 cM around the Vf gene. Using these 11 recombinants, we achieved fine-resolution of several AFLP-derived SCAR markers surrounding the Vf gene, resulting in the following genetic linkage map: ACS-6 and ACS are located left of the Vf gene at genetic distances of 0.2 cM and 0.1 cM, respectively; ACS-7 and ACS-9 are inseparable from the Vf gene; ACS-8, ACS-10, and ACS-4 are located to the right of the Vf gene at genetic distances of 0.1 cM, 0.4 cM, and 0.5 cM, respectively; the remaining five SCARs-ACS-11, ACS-5, ACS-2, ACS-1, and AL07-are inseparable and are located right of the Vf gene at a genetic distance of 0.7 cM. By integrating this linkage data with our previous physical map, we generated a revised map of the narrowed-down region of Vf.
D001203:Ascomycota / Q000472:pathogenicity; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics*; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D027845:Malus / Q000235:genetics* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods*
D018744:DNA, Plant; D005819:Genetic Markers