Taxonomy and distribution of Carpobrotus spp. across its native and non-native ranges

The genus Carpobrotus N.E.Br. comprises 12 to 20 accepted species, most of which are native to South Africa. Three Carpobrotus species (C. acinaciformis, C. chilensis and C. edulis) are currently considered among the most dangerous invasive species worldwide. In the introduced areas, these species represent a serious threat for native species, and are major drivers of shifts in soil conditions and disruptions of soil geochemical processes. Despite being intensively studied, the taxonomy of Carpobrotus remains problematic, and the genus is considered as a complex of species that easily hybridize and are difficult to distinguish. This is further complicated by the fact that clonal growth stabilizes hybrid combinations. Aiming to explore the population genetic structure of Carpobrotus taxa through their native and non-native ranges, we sampled populations of Carpobrotus in Argentina, Australia, Azores (Portugal), Italy, New Zealand, South Africa, Spain, and California (USA). Then, we developed taxon-specific microsatellite markers using Next Generation Sequencing approaches and used them to analyze the incidence of hybridization in native and non-native regions. Overall, we found three potentially distinct genetic clusters, which are present in both the native and non-native regions. Here, we discuss these results and their potential implication for the invasion and management of Carpobrotus species