DISTRIBUTION OF RAPD MARKERS ON A LINKAGE MAP OF BARLEY

The RAPD technique was found to provide reliable genetic markers in ba rley. A linkage study of 23 RAPDs, 28 RFLPs, and 29 gene loci was cond ucted on 72 chromosome-doubled haploid progeny lines from a barley cro ss. The resulting linkage map covered 680 cM, about half of the barley genome. RAPD markers were distributed throughout the map, but a highe r than expected frequency of tightly linked RAPDs was observed. Severa l cases of skewed segregation ratios were observed, but the RAPD marke rs segregated in ratios similar to their linked loci, confirming that they were reliably scored. In separate crosses, two amplified RAPD pro ducts, generated by different primers, were shown to reside in corresp onding chromosomal positions. The RAPD markers seem a realistic altern ative to RFLP markers in linkage analysis of barley.