Absence of geographic structure in European populations of Rubus fruticosus (L.) complex using chloroplast DNA microsatellites.

Twenty populations of the aggregate species Rubus fruticosus L. were collected throughout European natural forests and analysed by chloroplast microsatellites (SSR). Results showed high genetic diversity (hT = 0.73) and allelic richness (17 haplotypes were detected), and the presence of several unique alleles. On the other hand, the value of genetic differentiation between populations was low for unordered alleles (GST = 0.29) and for ordered alleles (NST = 0.30), revealing the absence of geographic structure of the haplotypic diversity. This can be mainly ascribed to the mechanisms of seed dispersal, mostly mediated by animal ingestion, which are responsible for a particularly efficient gene flow through seeds. Rubus species are characterised by the ability in colonising disturbed but also intact forest communities and hybridising with native species, therefore the possibility of tracing alien material with appropriate molecular markers can be useful for identifying and certifying the origin of accessions.