Migratory plant parasitic nematodes from the genus Pratylenchus are major pests in agriculture and attack a wide spectrum of crops leading to heavy losses up to 16% of grain yield in barley. Breeding resistant varieties is the most effective and environmentally friendly approach to control root lesion nematodes. A doubled haploid population derived from a cross between the Turkish accession Beysehir and the old German variety Valentina were used for genetic mapping of P. neglectus resistance QTLs. A genetic linkage map was constructed using 226 DH lines with 388 AFLP, SSR and CAPS markers that cover 1,051 cM on seven linkage groups. Using nematode numbers which were counted 7 weeks after artificial infection, eight QTLs were mapped by composite interval mapping on six linkage groups (2H, 3H, 4H, 5H, 6H and 7H). Comparative QTL analysis revealed that two major QTLs are located at the same position as previously described Pratylenchus resistance QTLs on chromosomes 5 and 6 (Rlnnp5H and Rlnnp6H) which had been mapped with two different. Two markers flanking Rlnnp6H are being used to identify DH lines with recombinations within the QTL regions in a large DH population of Beysehir × Valentina. Currently, 760 DH lines have been genotyped with the two flanking markers and 35 recombinant DHs were identified. Recombinant DH lines will be used for fine mapping of the QTL taking the markers selected by whole genome sequencing of two phenotypic bulks. Two phenotypic bulks representing the distributional extremes of the mapping population were subjected to whole genome sequencing using Illumina HiSeq 2000 technology. Short reads from the susceptible bulk were aligned to the barley reference genome sequence, and a consensus reference sequence was obtained. Reads from the resistant bulk were mapped to the consensus reference sequence and variants between the two bulks were identified. Homozygous variants densities were calculated across all chromosomes in a sliding window of 1Mb using CLC Genomics Workbench 6.5. Preliminary results show that a unique region with the highest variant density was localized at the same position as one of the resistance QTL. Sequence analysis to identify resistance candidates is in progress.