polymorphic microsatellite in the 3' end of 'waxy' genes of wheat, Triticum aestivum

Potential polymorphism of an (AT)n microsatellite at the 3' end of waxy genes in bread wheat was examined. Primers were designed from a published cDNA sequence of a wheat waxy gene. Polymerase chain reaction (PCR) amplification of genomic DNA from 135 mainly Australian cultivars revealed eight alleles on chromosomes 7A. This polymorphic microsatellite is a potential codominant marker for the Wx-Al locus in breeding programmes. A distinguishable fragment was also amplified from chromosome 7D. This fragment was absent where a plant was null for the waxy gene on chromosome 7D, being a dominant marker for the Wx-Dl locus. The primers were also useful for amplifying genomic DNA from barley, rye and triticale and can be used to detect potential polymorphism in these species.