DNA pooling strategy for saturation mapping in outbred crosses

We present a method to identify molecular markers linked to a genomic interval in outbred pedigrees. Using information from fully informative RFLP markers on a single linkage group containing a quantitative trait locus for wood specific gravity, we constructed four DNA pools from nonrecombinant progeny of a three-generation outbred pedigree. The four pools were screened to identify linked RAPD markers. The phase and zygosity of a linked RAPD marker could be determined directly from the array of RAPD bands present or absent in the four pools. Two hundred fifty-six primers were tested on the four DNA pools, revealing 61 putatively linked loci. Nine RAPD loci were linked to the genomic interval. The approach developed here could be generally applied to saturation mapping in outbred pedigrees where fully informative markers have previously been mapped.