
Important questions in genome evolution, particularly in regard to the evolution of gene families and genome structure, can only be addressed by the analysis of large contiguous blocks of DNA sequence from multiple species within the same family. Few such analyses have been performed on plant genomes, however, because of the wide phylogenetic distances between the best-sampled genomes, Arabidopsis thaliana, Medicago truncatula, and rice. To address this knowledge gap, a consortium of laboratories in the USA has been funded by the US National Science Foundation to sequence and compare an approximately 1 megabasepair interval from each of 6 legume taxa, with soybean (Glycine max) serving as the focus for their comparisons. These 6 taxa were chosen to allow this group to address fundamental questions regarding genome evolution on both short (<100,000 years) and long (>50 million years) time scales.
In the present project, this approximately 1 megabase genomic region from two genotypes of Phaseolus vulgaris (common bean) of Andean and Meso-american origin will be sequenced. This genomic interval contains several economically important disease resistance genes in soybean and beans. These analyses will address fundamental questions regarding genome evolution on both short and long time scales, as well as questions regarding the evolution of R genes.