title: Population structure of barley landrace populations and gene-flow with modern varieties.
abstract: Landraces are heterogeneous plant varieties that are reproduced by farmers as populations that are subject to both artificial and natural selection. Landraces are distinguished by farmers due to their specific traits, and different farmers often grow different populations of the same landrace. We used simple sequence repeats (SSRs) to analyse 12 barley landrace populations from Sardinia from two collections spanning 10 years. We analysed the population structure, and compared the population diversity of the landraces that were collected at field level (population). We used a representative pool of barley varieties for diversity comparisons and to analyse the effects of gene flow from modern varieties. We found that the Sardinian landraces are a distinct gene pool from those of both two-row and six-row barley varieties. There is also a low, but significant, mean level and population-dependent level of introgression from the modern varieties into the Sardinian landraces. Moreover, we show that the Sardinian landraces have the same level of gene diversity as the representative sample of modern commercial varieties grown in Italy in the last decades, even within population level. Thus, these populations represent crucial sources of germplasm that will be useful for crop improvement and for population genomics studies and association mapping, to identify genes, loci and genome regions responsible for adaptive variations. Our data also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change, and that in-situ conservation strategies based on farmer use can preserve the genetic identity of landraces while allowing adaptation to local environments.
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bellucci
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 Agraria, Università degli Studi di Sassari, Sassari, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Rau
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Nanni
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Ferradini
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giardini
authors.affiliation: Dipartimento di Agraria, Università degli Studi di Sassari, Sassari, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Rodriguez
authors.affiliation: Dipartimento di Agraria, Università degli Studi di Sassari, Sassari, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Attene
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy ; Consiglio per la Ricerca e Sperimentazione in Agricoltura, Cereal Research Centre (CRA-CER), Foggia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Papa
mesh_terms: D051456:Gene Flow; D056426:Genetic Loci / Q000235:genetics; D001467:Hordeum / Q000235:genetics*; D006824:Hybridization, Genetic; D018895:Microsatellite Repeats / Q000235:genetics; D062206:Spatial Analysis