Meeting Abstract

S9-2.1  Saturday, Jan. 7  Polyploidy in Plants and Animals BARKER, MS; RUNDELL, RJ*; University of Arizona; University of Arizona msbarker@email.arizona.edu

Polyploidy, or whole genome duplication, is recognized as an important feature of eukaryotic genome evolution. Among eukaryotes, polyploidy has arguably had the largest evolutionary impact on vascular plants where many contemporary species are of recent polyploid origin. Recent genomic analyses also demonstrate that most plants experienced at least one round of ancient polyploidy, or paleopolyploidy. Thus, polyploidy is clearly an important component of plant diversity. However, it is not clear if polyploidy uniquely contributes to plant diversity relative to diploids. Using comprehensive genomic, biogeographic, and chromosomal data sets I evaluate the relative contributions of polyploidy and diploidy to the evolutionary and ecological diversity of vascular plants. Genomic analyses indicate that nearly 60 ancient genome duplications have occurred in the history of green plants, and at surprisingly similar rate across seed plant evolution. Analyses of diversification indicate that although recent polyploidy species have high extinction rates relative to diploid congeners, ancient polyploids are significantly associated with outstanding increases in plant diversity. Overall, these results indicate that recent and ancient polyploidy are conspicuous features of plant genomes, and their frequency in plants may be a consequence of the high rate of polyploid production and rare successful species rather than outstanding features of polyploid biology in general relative to diploids.