A simple sequence repeat-based linkage map of barley

A total of 568 new simple sequence repeat (SSR)-based markers for barley ha ve been developed from a combination of database sequences and small insert genomic libraries enriched for a range of short simple sequence repeats. A nalysis of the SSRs on 16 barley cultivars revealed variable levels of info rmativeness but no obvious correlation was found with SSR repeat length, mo tif type, or map position. Of the 568 SSRs developed, 242 were genetically mapped, 216 with 37 previously published SSRs in a single doubled-haploid p opulation derived from the Fl of an interspecific cross between the cultiva r Lina and Hordeum spontaneum Canada Park and 26 SSRs in two other mapping populations. A total of 27 SSRs amplified multiple loci. Centromeric cluste ring of markers was observed in the main mapping population; however, the c lustering severity was reduced in intraspecific crosses, supporting the not ion that the observed marker distribution was largely a genetical effect. T he mapped SSRs provide a framework for rapidly assigning chromosomal design ations and polarity in future mapping programs in barley and a convenient a lternative to RFLP for aligning information derived from different populati ons. A list of the 242 primer pairs that amplify mapped SSRs from total bar ley genomic DNA is presented.