Phylogenetic relationships among low ploidy Poa species using chloroplast sequences

Species in the Poa genus are taxonomically and genetically difficult to delineate due to high and variable polyploidy, aneuploidy, and challenging breeding systems. Approximately 5% of the proposed species in Poa are considered to include or comprise diploids, but very few of those diploids are represented in seed collections. Recent phylogenetic studies of Poa have included some diploid species to elucidate Poa genome relationships. In this study we build upon that foundation of diploid Poa relationships with additional confirmed diploid species and accessions, and with additional chloroplast sequences. We also include a sample from P. pratensis and P. arachnifera to hone in on possible ancestral genomes in these two agronomic and highly polyploidy species. Relative to most of the Poa species, Poa section Dioicopoa (P. ligularis, P. iridifolia, and P. arachnifera) contained relatively large chromosomes. Phylogenies were constructed using the TLF gene region and five additional chloroplast genes, and the placement of new species and accessions fit within chloroplast lineages reported in Soreng et al. (2010) better than by taxonomic subgenera and sections. Low ploidy species in the â Pâ chloroplast lineage, such as P. iberica and P. remota, grouped closest to P. pratensis.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author