title: Understanding Genetic Diversity and Population Structure of a Poa pratensis Worldwide Collection through Morphological, Nuclear and Chloroplast Diversity Analysis.
abstract: Poa pratensis L. is a forage and turf grass species well adapted to a wide range of mesic to moist habitats. Due to its genome complexity little is known regarding evolution, genome composition and intraspecific phylogenetic relationships of this species. In the present study we investigated the morphological and genetic diversity of 33 P. pratensis accessions from 23 different countries using both nuclear and chloroplast molecular markers as well as flow cytometry of somatic tissues. This with the aim of shedding light on the genetic diversity and phylogenetic relationships of the collection that includes both cultivated and wild materials. Morphological characterization showed that the most relevant traits able to distinguish cultivated from wild forms were spring growth habit and leaf colour. The genome size analysis revealed high variability both within and between accessions in both wild and cultivated materials. The sequence analysis of the trnL-F chloroplast region revealed a low polymorphism level that could be the result of the complex mode of reproduction of this species. In addition, a strong reduction of chloroplast SSR variability was detected in cultivated materials, where only two alleles were conserved out of the four present in wild accessions. Contrarily, at nuclear level, high variability exist in the collection where the analysis of 11 SSR loci allowed the detection of a total of 91 different alleles. A Bayesian analysis performed on nuclear SSR data revealed that studied materials belong to two main clusters. While wild materials are equally represented in both clusters, the domesticated forms are mostly belonging to cluster P2 which is characterized by lower genetic diversity compared to the cluster P1. In the Neighbour Joining tree no clear distinction was found between accessions with the exception of those from China and Mongolia that were clearly separated from all the others.
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Raggi
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Bitocchi
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Russi
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Marconi
authors.affiliation: Department of Cytogenetics and Genome Analysis, Apomixis Research Group, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Sharbel
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Veronesi
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Emidio
authors.initials: E
authors.lastname: Albertini
mesh_terms: D002467:Cell Nucleus / Q000235:genetics*; D002736:Chloroplasts / Q000235:genetics*; D016000:Cluster Analysis; D018744:DNA, Plant / Q000235:genetics; D016002:Discriminant Analysis; D014644:Genetic Variation; D005828:Genetics, Population; D059646:Genome Size; D018745:Genome, Plant; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics; D058974:Phylogeography; D031785:Poa / Q000033:anatomy & histology* / Q000235:genetics*
chemical_list: D018744:DNA, Plant