CONSERVATION OF GENOME STRUCTURE BETWEEN RICE AND WHEAT

We have compared the structure of the genomes of rice and hexaploid br ead wheat, which speciated more than 60 million years ago, by reciproc al mapping of DNA probes. Results indicate that many wheat chromosomes contain homoeologous genes and genomic DNA fragments in a similar ord er to that found on rice chromosomes. This conservation of gene order along chromosomes differing in DNA content by some 30-fold, may provid e a basis for novel gene isolation strategies in wheat, one of the wor ld's major food crop species.