XVI International Botanical Congess

Across wide taxonomic ranges, plant genes show largely allelic types of difference, but repetitive DNA sequences vary widely in abundance and composition between closely related species, and between genomes in hybrid species. As a consequence, in situ hybridization of total genomic DNA from an ancestral species may label uniformly one genome in a hybrid species. Individual repetitive DNA families, whether dispersed or tandemly repeated, may be magnitudes more abundant in one genome than another. Processes of sequence divergence and homogenization apply to all repetitive sequences, but work at different rates on different sequences. Thus some repeats can be used to trace phylogenies, while others track genome-origin in hybrids or parents in plant breeding. Data are significant for understanding plant evolution and assessing biodiversity. For more information search http://www.jic.bbsrc.ac.uk.