Genetic structure and diversity of the selfing model grass Brachypodium stacei (Poaceae) in Western Mediterranean: out of the Iberian Peninsula and into the islands

Shiposha, V. ; Catalan, P. (Universidad de Zaragoza) ; Olonova, M. ; Marques, I.

Resumen: Annual Mediterranean species of the genus Brachypodiurn are promising model plants for energy crops since their selfing nature and short-life cycles are an advantage in breeding programs. The false brome, B. distachyon, has already been sequenced and new genomic initiatives have triggered the de-novo genuine sequencing of its close relatives such as B. stacei, a species that was until recently mistaken for B. distachyon. However, the success of these initiatives hinges on detailed knowledge about the distribution of genetic variation within and among populations for the effective use of germplasm in la breeding program. Understanding population genetic diversity and genetic structure is also an important prerequisite for designing effective experimental populations for genomic wide studies. However, population genetic data are still limited in B. stacei. We therefore selected and amplified 10 nuclear microsatellite markers to depict patterns of population structure and genetic variation 13 among 181 individuals from 19 populations of B. stacei occurring in its predominant range, the western Mediterranean area: mainland Iberian Peninsula, continental Balearic Islands and oceanic Canary Islands. Our genetic results support the occurrence of a predominant selfing system with extremely high levels of homozygosity across the analyzed populations. Despite the low level of genetic variation found, two different genetic clusters were retrieved, one clustering all SE Iberian mainland populations and the island of Minorca and another one grouping all SE Iberian mainland populations, the Canary Islands and all Majorcan populations except one that clustered with the former group. These results, together with a high sharing of alleles (89%) suggest different colonization routes from the mainland Iberian Peninsula into the islands. A recent colonization scenario could explain the relatively low levels of genetic diversity and low number of alleles found in the Canary Islands populations while older colonization events are hypothesized to explain the high genetic diversity values found in the Majorcan populations. Our study provides widely applicable information about geographical patterns of genetic variation in B. stacei. Among others, the genetic pattern and the existence of local alleles will need to be adequately reflected in the germplasm collection of B. stacei for efficient genome wide association studies.

Idioma: Inglés

DOI: 10.7717/peerj.2407

Año: 2016

Publicado en: PeerJ 4 (2016), [23 pp.]
ISSN: 2167-8359

Factor impacto JCR: 2.177 (2016)

Categ. JCR: MULTIDISCIPLINARY SCIENCES rank: 19 / 63 = 0.302 (2016) - Q2 - T1

Factor impacto SCIMAGO: 1.124 - Agricultural and Biological Sciences (miscellaneous) (Q1) - Biochemistry, Genetics and Molecular Biology (miscellaneous) (Q1) - Medicine (miscellaneous) (Q1) - Neuroscience (miscellaneous) (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA/Bioflora
Financiación: info:eu-repo/grantAgreement/EC/FP7/301257/EU/The model plant system Trithuria (Hydatellaceae), a new window into the origin of flowering plants and gene function/ORIGIN
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CGL2012-39953-C02-01

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Botánica (Dpto. CC.Agrar.y Medio Natural)