Origin and subdivision ofPlagiochila(Jungermanniidae: Plagiochilaceae) in tropical Africa based on evidence from nuclear and chloroplast DNA sequences and morphology

Abstract

Maximum likelihood analyses based on the internal transcribed spacer region of nuclear ribosomal DNA and the chloroplast protein coding gene rps4 were conducted to investigate phylogenetic relationships among species of Plagiochila and to reconstruct the ranges of natural species groups within the genus. Based on the results of the molecular analyses and on morphological evidence, the tropical African species of Plagiochila are assigned to the sections Arrectae, Cucullatae, Hylacoetes, Rutilantes, Vagae, and the new sect. Africanae ( P. barteri, P. colorans ). With the exception of Africanae, all sections possess intercontinental ranges; their centers of diversity are in the tropics. Clade and species diversity in Africa is lower than in other parts of the tropics and may reflect drought periods of the Pleistocene. Intercontinental ranges at specific level exist between tropical America and Africa whereas similarities between tropical Asia and Africa were only recovered at the sectional level. ITS sequence sets were used to test the monophyly of species with intercontinental ranges and to explore the development of the Afro‐American range of P. boryana. A well supported clade with accessions of P. boryana from Bolivia and Uganda is nested in the robust neotropical Hylacoetes. This topology and the low genetic distance of the different P. boryana accessions provide some evidence for long‐range dispersal of P. boryana eastwards across the Atlantic, originating from the Neotropics. An African origin of the Vagae clade which includes neotropical and paleotropical taxa is suggested by the clustering of accessions from the East African Islands at the base of this clade. In addition, the presented data support the hypothesis of several switches from Africa to Asia and vice versa. A derived clade within Vagae includes accessions from the African mainland and the Neotropics. Our results seem to indicate that the extant tropical African Plagiochila flora is a mixture of old elements and rather recent immigrants.

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.…”

“…(Heinrichs et al, 2009b), Plagiochila punctata (Taylor) Taylor (Davison et al, 2006), Plagiochila boryana Steph. (Heinrichs et al, 2005b), Symphyogyna podophylla (Thunb.) Nees & Mont.…”

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.…”

The systematic position ofPlagiochila(Jamesoniella)dependula(Jungermanniopsida) inferred from nrITS sequences and morphology, with notes on its differentiation fromPlagiochila fuscolutea

“…With the exception of two species (P. boryana and P. heterophylla ;Heinrichs, 2002;Heinrichs et al, 2005a), representatives of Plagiochila clade A are restricted to the Neotropics. Plagiochila (sect.…”

“…Twenty-seven ITS1-, 5.8S-and ITS2-sequences from Heinrichs (2002), Heinrichs et al (2002aHeinrichs et al ( , b, 2003Heinrichs et al ( , 2005a, Renker et al (2002), and the two new sequences (Table 1) were aligned manually in BioEdit version 5.0.9 (Hall, 1999), resulting in an alignment including 740 putatively homologous sites (alignment available from JHei).…”