CONSTRUCTION OF AN RFLP LINKAGE MAP FOR CULTIVATED SUNFLOWER

An RFLP linkage map was constructed for cultivated sunflower Helianthu s annuus L., based on 271 loci detected by 232 cDNA probes. Ninety-thr ee F-2 plants of a cross between inbred lines RHA 271 and HA 234 were used as the mapping population. These genetic markers plus a fertility restoration gene, Rf(1), defined 20 linkage groups, covering 1164 cM of the sunflower genome. Of the 271 loci 202 had codominant genotypic segregation, with the rest showing dominant segregation. Thirty-two of the 232 probes gave multiple locus segregation. There were 39 cluster s of tightly linked markers with 0 cM distance among loci. This map ha s an average marker-to-marker distance of 4.6 cM, with 11 markerless r egions exceeding 20 cM.