Apomixis and reticulate evolution in Aspleniaceae

Ferns have the highest proportion of apomictic species in all plant groups, but the reasons for this are unclear. Dyer et al. determine the reproductive mode of species in the Asplenium monanthes fern complex, and use plastid and nuclear sequence data to resolve species’ relationships. They find that reticulate evolution is prevalent in apomictic and sexual lineages, and there is evidence for rare putative sexual progenitor species and multiple origins of apomixis. However, it is not yet possible to determine the precise mechanisms of origin, or whether this association of apomixis with reticulation is the cause or the effect of apomictic origins within this complex.