New insights in the evolution of the liverwort family Aneuraceae (Metzgeriales, Marchantiophyta), with emphasis on the genus Lobatiriccardia

Abstract

Phylogenetic analyses using two fast evolving plastid markers (rps4, trnL‐F) reveal the occurrence of the Australasiatic liverwort genus Lobatiriccardia in the Neotropics. Two new species, Lobatiriccardia oberwinkleri and L. verdoornioides are reported from Ecuador. Phylogenetic reconstructions support Lobatiriccardia and Aneura as monophyletic sister groups and do not place Verdoornia as the first branching Aneuracean taxon but rather sister to Aneura and Lobatiriccardia, which is consistent with mycothallus development in Aneuraceae. Subsequently, Aneuraceae, as treated here, include Aneura, Lobati‐ riccardia, Riccardia, and Verdoornia. Although high levels of genetic structure can be observed among members of the Aneura pinguis complex, current species delimitations are questionable, and detailed analyses of cryptic speciation and biogeographic patterns are needed to understand the evolution of Aneura, with particular attention paid to the non‐photosynthetic species Aneura mirabilis. Ancestral state reconstructions suggest an evolutionary trend of female gametangia, and subsequently the sporophyte, moving from a central position on the dorsal side of the thallus (Verdoornia) to a marginal position between thallus lobes (Lobatiriccardia) to a more ventral (quasi latero‐ventral) position under the thallus margin (Aneura).

Aneuraceae (Metzgeriales) and tulasnelloid fungi (Basidiomycota) – a model for early steps in fungal symbiosis

“…The non-mycorrhizal Riccardia amazonica (Spruce) Schiffner ex Gradst. & Hekking (Beck et al 2008) is closely related to the mycobiontic species and the derived Riccardia andina (Spruce) Herzog clade (Preußing et al 2010b). The lack of fungal symbionts in the R. andina clade is probably the result of a secondary loss caused by erect growth under very wet conditions (Nebel, unpublished data).…”

“…Molecular phylogenetic analysis of the European and some South American Riccardia taxa suggests that fungus-free states occur in both early diverging and derived lineages (Preußing et al 2010b). The non-mycorrhizal Riccardia amazonica (Spruce) Schiffner ex Gradst.…”

“…The latter ones are the sites of entry for the fungi (Duckett & Ligrone 2008). The colonisation patterns in the parenchymal cells differ mainly in the number of colonised layers (Ligrone et al 1993;Duckett & Ligrone 2008;Preußing et al 2010b). In most of the Riccardia species, the thalli are free of fungal colonisation (Hewson 1970;Brown & Braggins 1989;Nebel et al 2004;Duckett & Ligrone 2008).…”

“…They occur in the genera Aneura (Bidartondo et al 2003;Kottke et al 2003;Kottke et al 2008;Bidartondo & Duckett 2010;Preußing et al 2010a Preußing et al 2010b). Within liverworts, so far, Tulasnellales have been found only in the Aneuraceae.…”

“…Fungal colonisation of both the epidermal and adjacent parenchymal cells was reported in seven Riccardia species from South America, New Guinea, New Zealand, and Australia (Hewson 1970;H€ assel de Men endez 1972;Brown & Braggins 1989). The colonisation of only parenchymal cells is known from three New Guinean Riccardia species (Hewson 1970) and the South American Riccardia smaragdina Meenks & C. De Jong (Preußing et al 2010b).…”