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.