Plant kleptomaniacs: geographic genetic patterns in the amphi-apomicticRubusser.Glandulosi(Rosaceae) reveal complex reticulate evolution of Eurasian brambles

Rubus ser. Glandulosi represents a unique model of geographic parthenogenesis on a homoploid (4x) level. We employed double digest restriction-site associated DNA sequencing (ddRADseq) in 587 individuals of different Rubus taxa and modelling of suitable climate to characterize evolutionary and phylogeographic patterns and shed light on the geographic differentiation of apomicts and sexuals. Six ancestral species were identified that contributed to the contemporary gene pool of R. ser. Glandulosi . While sexuals were introgressed from R. dolichocarpus and R. moschus in West Asia and from R. ulmifolius agg., R. canescens and R. incanescens in Europe, apomicts were characterized by alleles of R. subsect. Rubus . Gene flow between sexuals and apomicts was also detected, as well as occasional hybridization with other taxa. We hypothesize that sexuals survived the last glacial period in several large southern refugia, whereas apomicts were mostly restricted to southern France from whence they quickly recolonized Central and Western Europe. The secondary contact of sexuals and apomicts was probably the principal factor that established geographic parthenogenesis in R. ser. Glandulosi . Sexual populations are not impoverished in genetic diversity along their borderline with apomicts and maladaptive population genetic processes likely did not shape the geographic patterns. Highlights Geographic parthenogenesis in Rubus ser. Glandulosi is caused by secondary contact Reticulate evolution in Eurasian brambles is more extensive than expected At least six species contributed to the evolution of Rubus ser. Glandulosi Extinct ancestor’s gene pool is associated with apomixis Abstract Figure Graphical abstract