A genetic map of 1,000 SSR and DArT markers in a wide barley cross

A high-density genetic map was developed from an F1-derived doubled haploid population generated from a cross between cultivated barley (Hordeum vulgare) and the subspecies H. vulgare ssp. spontaneum. The map comprises 1,000 loci, amplified using 536 SSR (558 loci) and 442 DArT markers. Of the SSRs, 149 markers (153 loci) were derived from barley ESTs, and 7 from wheat ESTs. A high level of polymorphism ( approximately 70%) was observed, which facilitated the mapping of 197 SSRs for which genetic assignments had not been previously reported. Comparison with a published composite map showed a high level of co-linearity and telomeric coverage on all seven chromosomes. This map provides access to previously unmapped SSRs, improved genome coverage due to the integration of DArT and EST-SSRs and overcomes locus order issues of composite maps constructed from the alignment of several genetic maps.