Plant & Animal Genomes XVII Conference Plant & Animal Genomes XVII ConferenceJanuary 10-14, 2009
Town & Country Convention Center
San Diego, CA
The tribe Brassiceae and the genus Brassica are characterized by the wide diversity of chromosome numbers spanning the range from 2n=14 to 2n=120 (2n=16-38 in Brassica). Whereas relatively recent polyploidy events resulting in elevated chromosome numbers (2n=34, 36, 38) have been recognized in Brassica more than seventy decades ago, paleo- and mesopolyploidy events shaping the genome structure of bona fide diploid brassicas (2n=16, 18, 20) were revealed only recently. I will demonstrate how the genome evolution in the Brassiceae was driven by multiple paleopolyploidy events, the later tribe-specific whole-genome triplication (mesopolyploidy) followed by karyotype shuffling, and recent allopolyploidization. Due to conserved chromosome collinearity between brassicas and other crucifer species including Arabidopsis thaliana, tentative evolutionary scenarios of Brassica genome evolution can be reconstructed. It will be shown how the present-day Brassica genomes are related to those of other tribes and reconstructed ancestral karyotypes.