A Durum Wheat Consensus Map Based on Fourteen Mapping Populations

In durum wheat, several intra-specific mapping populations have recently been developed. As a result of this effort, a number of QTLs/major loci for disease and abiotic stresses responses, yield- and quality-related traits have been mapped to simple sequence repeat (SSR) and DArT® markers. Furthermore, new SNP-based genotyping platforms were made available for wheat (USDA wheat SNP database and http://www.cerealsdb.uk.net/) and SNP mapping is currently underway in both species. A consensus map specific of durum wheat would provide a valuable framework for more detailed mapping in this species. Genotype data of 14 mapping populations were used for integrated mapping. The original genotypic data were used to recalculate the linkage maps applying pre-mapping quality filtering and a combination of JoinMap v. 4.0 and Carthagene v. 2.0 for mapping. Six RIL populations were chosen to build a framework consensus map with a subset of common markers bridging two or more populations with homogeneous recombination rates. Additional markers mapped in a single population were projected by interpolation (Cone et al. Plant Physiol. 2002. 130: 1594–1601). Marker interpolation was used to add all the markers from the other eight component maps. In the final framework map, 598 common SSR, DArT® and SNP markers were grouped into 18 linkage groups, yielding a framework map of 2,239 cM, with an average inter-marker distance of 3.74 cM/marker. The interpolation of markers from the additional populations resulted in a final map of 2,463 cM including 2,575 markers. This refined set of data will be useful to integrate the new SNP markers that are being produced.