CONSERVATION OF MARKER SYNTENY DURING EVOLUTION

An aspect of cereal science that is becoming increasingly important is comparative genetics. Establishment of the relationship between genom es within polyploids, between species within tribes and between specie s within families will allow not only the integration of genetic maps but also the knowledge acquired of each of the species. Using a set of homoeologous probes, workers found the relationship between the three wheat genomes to be precisely collinear, after taking a few major tra nslocation events into account. Transfer of the wheat map to rye led t o the elucidation of similar relationships between the three wheat gen omes and that of rye. Genome collinearity, however, extends even beyon d tribes. In a comparison of the genomes of wheat, rice and maize, it was shown that despite the separation of these genomes for possibly 50 million years, gene order was still highly conserved. This collineari ty between genomes can be exploited in a number of ways.