Genetic diversity of Avena ventricosa populations along an ecogeographical transect in Cyprus is correlated to environmental variables

Avena ventricosa Balansa ex Coss. is considered the C-genome donor of the cultivated hexaploid oat and is a ‘priority’ species for conservation, since it has limited geographic distribution and the only recorded populations in Europe are present in Cyprus. The current study attempts to characterize the genetic structure and fragmentation of the species via the application of genotypic markers. It was revealed that the genetic variety was mainly allocated among the populations collected, since clustering obtained was according to the geographic origin of the samples and the habitat. Species distribution modeling showed that the most important climatic variable defining A. ventricosa distribution is the mean diurnal temperature. Furthermore, significant association of the genetic structure to environmental variables was detected; overall, a negative association to precipitation was confirmed, while significant correlations of genetic structure and the temperature at the time of anthesis and germination were established. The safeguarding of this valuable genetic resource is discussed.

Protocol publication

[…] All fragment sizes were transformed into binary data (presence/absence) and organized in a single matrix table. FreeTree [] was employed to compute the genetic similarities between taxa and for the construction of the dendrogram, illustrated with the TreeView application (http://taxonomy.zoology.gla.ac.uk/rod/treeview.html). Popgene [] was used to estimate Shannon diversity index and the percentage of polymorphic loci, as well as, for the construction of the population level dendrogram. Genotypic variations were calculated across various populations via the analysis of molecular variance (AMOVA) using GenAlEx 6.5 []. The significance of the resulting variance components and the inter-population genetic distances were tested using 999 random permutations.Bayesian model-based clustering approach was used in order to identify the genetic structure of the Avena ventricosa populations, with the Structure 2.3.4 software []. The Structure algorithm was run using the admixture model, with 10 independent replicate runs per K value (number of clusters) ranging from 1 to 10. Each run involved a burning period of 100,000 iterations, and a post burning simulation length of 500,000. Validation of the most likely number of clusters K and graphical representations of cluster assignments was performed with pophelper (http://royfrancis.github.io/pophelper/). […]