COMPARATIVE GENOME MAPPING OF SUGAR-CANE WITH OTHER SPECIES WITHIN THE ANDROPOGONEAE TRIBE

Comparative mapping within the tribe Andropogoneae has recently progre ssed with the development of mapped maize genomic probes that can be u sed for sorghum and sugar cane genomes. In the present study, data fro m previous reports were used to locate various linkage groups of sugar cane and sorghum on the genomic map of maize. Syntenic genome regions in the three plants were determined according to existing bridge-loci . The distribution of these synteny clusters closely matched the dupli cation pattern in maize. In several cases, the two arms of a single ma ize chromosome corresponded to at least two synteny clusters. There se em to be common chromosome rearrangements between maize and sugar cane and between maize and sorghum. In this respect, sugar cane and sorghu m appear to be more closely related than either one with maize. A more detailed analysis of two synteny clusters was undertaken using recent sugar cane data to compare gene orders and recombination rates of the three plants. The three genomes showed colinearity in these regions. Distances between genes were similar in maize and sorghum, whereas sug ar cane tended to display less recombination, at least in the varietal progeny investigated.