The possibility of using linkage disequilibrium mapping in natural plant populations was assessed.
In studying linkage disequilibrium among 137 mapped AFLP markers in four populations of sea
beet (Beta vulgaris ssp. maritima (L.) Arcang.) it was shown that tightly linked loci could be
detected by screening for associations. It was hypothesized that the short distances spanned by
linkage disequilibrium enable markers that are very tightly linked to a target gene to be identified.
The hypothesis was tested by whole-genome screening of AFLP markers for association with the
gene for the annual growth habit, the B gene, in a sample of 106 sea beets. Despite the dominant
nature of AFLP, two markers showing significant linkage disequilibrium with the B gene were
detected. The results indicate the potential use of linkage disequilibrium for gene mapping in
natural plant populations.