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The new species Astrothelium inspersaeneum and Diorygma longisporum are described from northeastern Brazil. These species were all found only in the Caatinga reserve Vale do Catimbau in Pernambuco. The Astrothelium is, according to current key characters, referable to the genus Trypethelium, but it is clearly a member of the Astrothelium conicum-group and thus described in that genus.
Trevigen's HT Colorimetric PARP/Apoptosis Assay was used to determine the effect of three flavones on PARP-like activity associated with DNA repair in thalli of Marchantia polymorpha exposed to prior UV-C radiation when compared to white light-exposed controls. Thalli placed in solutions of the naturally-occurring flavones apigenin and quercetin showed significantly decreased PARP-like activity after UV-C exposure, but thalli in luteolin solution showed increased PARP-like activity when compared to PBS-treated controls. These effects were not seen with exposure to white light alone when compared to PBS-treated controls. This research is the first to be conducted in bryophytes and suggests a critical control point for PARP-like activity in these organisms.
While the distribution and ranges of arctic plants were greatly affected by the advance and retreat of ice sheets, the impact of glacial and interglacial cycles on lichenized fungi remains largely unexplored. In this study we examine the impact of Pleistocene climatic changes on two closely related Xanthomendoza (Teloschistaceae, Ascomycota) species with distinct distribution patterns and reproductive strategies. We selected X. borealis, which occurs in polar regions of both hemispheres, and the corticolous X. montana, which is restricted to montane shrublands in western North America. We analyzed the complete nuclear ribosomal internal transcribed spacer region (ITS) to confirm the monophyly and relative ages of X. borealis and X. montana. We estimated molecular diversity and population demographics statistics, mismatch distributions, and Bayesian skyline plots for both species. Our data indicate that X. montana experienced a Late Pleistocene population expansion. We suggest that major shifts in vegetation types as a result of Pleistocene climate change had a substantial impact on distribution patterns and the demographic history of X. montana. In contrast, results from this study indicate that the demographic history of X. borealis is consistent with long-term stability, although low genetic variability in the ITS marker for X. borealis limits overall confidence in this inference. We propose that X. borealis has been able to maintain a stable population size across climatic shifts, likely through effective dispersal to suitable habitats and suggests that climatic conditions during Pleistocene glacial cycles were not inherently unfavorable or restrictive for some high altitude/latitude lichen-forming fungal species. Investigating mating systems for these two Xanthomendoza species may provide important insights about the factors affecting population demographics and reproduction in lichen-forming fungi in general.
Pyrenula sanguinea Aptroot, M. Cáceres & Lücking is described from branches of trees in Amazonian rain forest in the state of Rondônia, Brazil. It is characterized by bright red, pseudostromatic ascomata with fused walls, closely resembling those of Trypethelium eluteriae and related species except for the color. The brown ascospores deviate from those of most other Pyrenula species by their reduced endospore formation; they are surrounded by a thick gelatinous sheath with horn-like and curled appendages at the tips. Although morphologically very distinct from all other known species of Pyrenula, molecular data of the mtSSU and nuLSU loci revealed that it is nested within that genus, with a strongly supported sister-group relationship with P. cruenta. Both species share the bright red color of ascomata, but co-chromatography revealed a distinct, complex pattern for P. sanguinea, with six different pigments, only haematommone shared with P. cruenta.
As part of an ongoing, comprehensive inventory of all Galapagos lichen species, the genus Bulbothrix is revised here. In Galapagos it is represented by five species of which only one, B. laevigatula, had previously been reported. Bulbothrix lyngei, B. scortella and B. subdissecta are all new to Galapagos; they also represent the first reports of these species for Ecuador. A fifth species, Bulbothrix bulbillosa, is described as new to science.
Four new species of Coenogonium are described from the Caribbean island of Puerto Rico—C. aurantiacum Mercado-Díaz & Lücking, C. borinquense Mercado-Díaz & Lücking, C. dimorphicum Mercado-Díaz & Lücking and C. portoricense Mercado-Díaz & Lücking. All were discovered in small and highly fragmented forest remnants of relatively rare Puerto Rican forest ecosystems, Pterocarpus wetlands and non-calcareous dry forests. The discoveries are discussed relative to the conservation status of these threatened ecosystems, the need to catalogue biodiversity before it vanishes, and the notion that endemism in lichenized fungi in island biotas is potentially much higher than hitherto assumed. A previous world-wide key to Coenogonium is updated to accommodate the new taxa.
Many alpine bryophytes rely primarily if not exclusively on gametophytic fragments for reproduction. The dispersal role of these fragments, however, has not been adequately addressed. The objective of this study was to determine the extent to which fragments disperse on alpine summits and the reproductive viability of those fragments. Airborne diaspores were collected from early spring snow deposits in 2008, 2009, and 2010 from the summit of Mt. Marcy, and from summer propagule traps placed on the summits of Mt. Marcy and Algonquin Peak in 2009 and 2010. All fragments collected were identified to genus and/or species, when possible. To test for reproductive viability, fragments were grown in nutrient agar under ambient conditions for a period of 17 weeks. To detect the presence of spores, collected debris was surface sterilized and cultured on separate dishes containing nutrient agar. A total of 6130 gametophytic fragments, representing 26 species, were collected. Collections were dominated by individual leaves (65%) and leafy branch fragments (32%). Up to 20% of fragments collected were found to be viable, with the majority of growth originating from stem tissue. In contrast, spore production was found to be uncommon to rare. The results of this study provide evidence that Adirondack alpine bryophyte populations are maintained by the production and dissemination of gametophore fragments during both winter and summer months, with infrequent spore production events, perhaps episodically when weather conditions are most suitable. Data also suggest that vegetative propagules may travel longer distances on these summits than originally predicted.
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