Evolutionary dynamics of grass genomes

The grass family (Poaceae) has been the subject of intense research over the past decade. Although other angiosperm families contain more species and more genera, Poaceae exceed all other families in ecological dominance and economic Research has focused on the evolutionary relationships among grasses well as the structure of grass genomes. Here I examine the evolutionary dynamics grass genomes in a phylogenetic framework. It is clear that grass genomes evolutionarily labile for many characteristics, including genome size and number. Variation in genome size among grasses probably reflects in the amount of repetitive DNA per genome, but the history and of chromosome number changes remain unclear. Despite substantial among genomes, comparative maps suggest that grass genomes retain regions of colinearity. By reanalyzing some comparative map data and by reviewing comparative sequence data, I argue that the current colinearity requires reassessment. (C) New Phytologist (2002).