AFLP-derived SCARs facilitate construction of a 1.1 Mb sequence-ready map of a region that spans the Vf locus in the apple genome.
The availability of high-density anchored markers is a prerequisite for reliable construction of a deep coverage BAC contig, which leads to creation of a sequence-ready map in the target chromosomal region. Unfortunately, such markers are not available for most plant species, including woody perennial plants. Here, we report on an efficient approach to build a megabase-size sequence-ready map in the apple genome for the Vf region containing apple scab resistance gene(s) by targeting AFLP-derived SCAR markers to this specific genomic region. A total of 11 AFLP-derived SCAR markers, previously tagged to the Vf locus, along with three other Vf-linked SCAR markers have been used to screen two apple genome BAC libraries. A single BAC contig which spans the Vf region at a physical distance of approximately 1,100 kb has been constructed by assembling the recovered BAC clones, followed by closure of inter-contig gaps. The contig is approximately 4 x deep, and provides a minimal tiling path of 16 contiguous and overlapping BAC clones, thus generating a sequence-ready map. Within the Vf region, duplication events have occurred frequently, and the Vf locus is restricted to the ca. 290 kb region covered by a minimum of three overlapping BAC clones.
Xu
Mingliang
M
Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana 61801, USA.
Korban
Schuyler S
SS
D001203:Ascomycota / Q000254:growth & development; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D003001:Cloning, Molecular; D020451:Contig Mapping; D018744:DNA, Plant / Q000235:genetics*; D015723:Gene Library; D018745:Genome, Plant; D007113:Immunity, Innate / Q000235:genetics; D027845:Malus / Q000235:genetics* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods*
D018744:DNA, Plant