AFLP FINGERPRINTING REVEALS PATTERN DIFFERENCES BETWEEN TEMPLATE DNA EXTRACTED FROM DIFFERENT PLANT ORGANS

AFLP (amplified fragment length polymorphism) fingerprinting of cultiv ars of bread wheat (Triticum aestivum) and some of its wild relatives has allowed the efficient detection of large numbers of polymorphic am plified fragments. While the reproducibility of fingerprints in repeat ed experiments is high, pattern differences were observed between fing erprints obtained from seed and leaf DNA template from the same wheat accession. These distinct organ specific amplified DNA fragments were shown to be due neither to genotypic mixtures nor to pathogen contamin ation. They are likely a result of differences in DNA methylation betw een organs. Even greater numbers of organ specific amplified fragments were observed when fingerprints obtained from the root and shoot of i ndividual seedlings of the wheat relatives Aegilops mutica and Aegilop s speltoides were compared. This phenomenon underlines the importance of ensuring that DNA is extracted from physiologically uniform tissue in phylogenetic studies based on AFLP fingerprints. For this purpose, mature seed is a convenient source.