Low levels of DNA sequence variation among adapted genotypes of hexaploid wheat

PCR products from regions corresponding to sequences hybridising to wheat R FLP probes were sequenced in order to establish the level of DNA sequence v ariation among adapted wheat genotypes. Hexaploid bread wheat shows a very low rate of nucleotide polymorphism, approximately 1 polymorphic nucleotide per 1000 basepairs. Differences in PCR product length can be exploited to design genome-specific amplicons, which may have use in gene tagging or in diagnostic applications. Interpretation of results may be complicated by th e simultaneous amplification of orthologous and paralogous sequences. These findings have significant implications for the use of STS markers in wheat and other polyploid species.