Phylogenetic biogeography of the leafy liverwort Herbertus (Jungermanniales, Herbertaceae) based on nuclear and chloroplast DNA sequence data: correlation between genetic variation and geographical distribution

Abstract

Aim The cosmopolitan genus Herbertus is notorious for having a difficult taxonomy and for the fact that there is limited knowledge of species ranges and relationships. Topologies generated from variable molecular markers are used to discuss biogeographical patterns in Herbertus and to compare them with the geological history of continents and outcomes reported for other land plants.Location Africa, Asia, Azores, Europe, southern South America, northern South America, North America, New Zealand.Methods Phylogenetic analyses of nuclear ribosomal internal transcribed spacer and chloroplast (cp) trnL-trnF sequences of 66 accessions of Herbertus and the outgroup species Triandrophyllum subtrifidum and Mastigophora diclados were used to investigate biogeographical patterns in Herbertus. Areas of putative endemism were defined based on the distribution of species included in the analyses. Maximum parsimony analyses were undertaken to reconstruct ancestral areas and intraspecies migration routes.Results The analyses reveal species-level cladograms with a correlation between genetic variation and the geographical distribution of the related accessions. The southern South American Herbertus runcinatus is sister to the remainder of the genus, which is split into two main clades. One contains the Neotropical-African Herbertus juniperoideus and the New Zealand/Tasmanian Herbertus oldfieldianus. An African accession of H. juniperoideus is nested within Neotropical accessions. The second main clade includes species that inhabit Asia, the Holarctic, Africa, and northern South America. Maximum parsimony analyses indicate that this clade arose in Asia. Herbertus sendtneri originated in Asia and subsequently colonized the Holarctic and northern South America. An Asian origin and colonization into Africa is indicated for H. dicranus. Main conclusionsThe current distribution of Herbertus cannot be explained by Gondwanan vicariance. A more feasible explanation of the range is a combination of short-distance dispersal, rare long-distance dispersal events (especially into regions that faced floral displacements as a result of climatic changes) extinction, recolonization, and diversification. The African Herbertus flora is a mixture of Asian and Neotropical elements. Southern South America harbours an isolated species. The molecular data indicate partial decoupling of molecular and morphological variation in Herbertus. Biogeographical patterns in Herbertus are not dissimilar to those of other groups of bryophytes, but elucidation of the geographical ranges requires a molecular approach. Some patterns could be the Journal of Biogeography (J. Biogeogr.) (2007) 34, 688-698 688

A phylogeny of Adelanthaceae (Jungermanniales, Marchantiophyta) based on nuclear and chloroplast DNA markers, with comments on classification, cryptic speciation and biogeography

“…A clear geographical structure was not observed in S. concreta, with the single African accession nested in one of the Neotropical subclades. The presence of African accessions in an otherwise exclusively Neotropical clade provides evidence for long range dispersal eastwards across the Atlantic, a scenario that has already been proposed for several clades of vascular plants (Renner, 2004) and liverworts (Heinrichs et al, 2005b;Feldberg et al, 2007). The geographical structure of some species clades and the restriction of some species ranges to single continents (Inoue, 1966;Grolle, 1972) indicate that successful long-distance dispersal is not a common phenomenon in Adelanthaceae.…”

A morphological revision of the genusHerbertusS.Gray (Herbertaceae, Marchantiophyta) in Africa, including the East African islands

“…More recent molecular studies have broadly supported these initial findings and added additional data (Juslén 2006b;Feldberg & Heinrichs 2006). In the broader study by Feldberg et al (2007), the small number of African specimens examined also showed limited variation, leading the authors to suggest that there may be only two species in Africa.…”

“…Grolle (1978) retained H. grossevittatus as a Mascarene endemic closely related to H. juniperoideus. More recent molecular work (Feldberg et al, 2007) has convincingly demonstrated the presence of H. juniperoideus in Africa. In the neotropics, H. juniperoideus is principally a Caribbean species.…”

“…Demaret, 1942;Hauman, 1942;Arnell, 1956Arnell, , 1963Arnell, , 1965Hodgetts, Matcham & Duckett, 1999, Ah Peng et al 2008. More recently, Feldberg et al (2007) have performed molecular analysis on a small number of African specimens, as part of a wider molecular study, and suggested that there may be only two species in Africa, H. dicranus and H. juniperoideus.…”

Molecular, morphological, and biogeographic perspectives on the classification of Acrobolboideae (Acrobolbaceae, Marchantiophyta)

“…Long-distance dispersal events are often interpreted as the likely explanation for liverwort diversification (Heinrichs et al 2009) and wide disjunctions in distributional ranges can be attributed to long-distance dispersal (e.g. Shaw et al 2003, Heinrichs et al 2005, Feldberg et al 2007). Our results suggest that long-distance dispersal has played a role in shaping the distributional ranges of Acrobolbus species but we are unable to rule out the impact of vicariance.…”