Comparative high resolution map of the six-rowed spike locus 1 (vrs1) in several populations of barley, Hordeum vulgare L.

Multiple alleles at the vrs1 locus control the development and fertility of the lateral spikelets of barley (Hordeum vulgare L.), which is a key character in the study of yield, utilization and domestication. In this study, six linkage maps of the vrs1 locus were constructed, using different mapping populations developed from nine different barley cultivars (H. vulgare subsp. vulgare) or mutant and wild barley (H. vulgare subsp. spontaneum). A total of 8387 chromosomes (gametes) were sampled for analysis based on a hypothesis that orders of marker loci were the same over the different parental lines. The results showed that four markers and the vrs1 locus in all cases were arranged in the same order, which was in a good agreement with the hypothesis. This makes the linkage maps suitable for the positional cloning of the alleles at the vrs1 locus.