20 research outputs found
Transoceanic Dispersal and Subsequent Diversification on Separate Continents Shaped Diversity of the Xanthoparmelia pulla Group (Ascomycota)
In traditional morphology-based concepts many species of lichenized fungi have world-wide distributions. Molecular data have revolutionized the species delimitation in lichens and have demonstrated that we underestimated the diversity of these organisms. The aim of this study is to explore the phylogeography and the evolutionary patterns of the Xanthoparmelia pulla group, a widespread group of one of largest genera of macrolichens. We used a dated phylogeny based on nuITS and nuLSU rDNA sequences and performed an ancestral range reconstruction to understand the processes and explain their current distribution, dating the divergence of the major lineages in the group. An inferred age of radiation of parmelioid lichens and the age of a Parmelia fossil were used as the calibration points for the phylogeny. The results show that many species of the X. pulla group as currently delimited are polyphyletic and five major lineages correlate with their geographical distribution and the biosynthetic pathways of secondary metabolites. South Africa is the area where the X. pulla group radiated during the Miocene times, and currently is the region with the highest genetic, morphological and chemical diversity. From this center of radiation the different lineages migrated by long-distance dispersal to others areas, where secondary radiations developed. The ancestral range reconstruction also detected that a secondary lineage migrated from Australia to South America via long-distance dispersal and subsequent continental radiation
High selectivity in symbiotic associations of lichenized ascomycetes and cyanobacteria
The selectivity of mycobionts and cyanobionts in lichen symbioses were examined. We analyzed symbiotic cyanobionts, collected from different sample sites, and compared them to free-living cyanobacteria Nostoc. Cyanobionts were obtained from lichens assigned to the genera Pseudocyphellaria and Sticta, in particular. Multiple gene loci were screened and direct optimization was used in the phylogenetic analyses. We show that many lichen fungi are strongly selective towards their cyanobionts. Lichenized ascomycetes seem to be able to identify and choose a specific strain, species or a species group of Nostoc with which to associate. The present analyses also suggest that some of the Nostoc taxa may be specialized in symbiotic life with only lichenized ascomycetes. Despite the selectivity observed in fungi, there appears to be no coevolution between the partners. We have also discussed the problems of using the tRNA(Leu) intron as a marker in phylogenetic analyses
Lichens, lichenicolous and allied fungi in Asveja Regional Park (Lithuania)
The paper reports the results of lichenological investigations in Asveja Regional Park (eastern Lithuania). A large part of the study was performed during the joint 18th Symposium of Baltic Mycologists and Lichenologists (BMLS) and Nordic Lichen Society meeting (NLF), September 19–23, 2011. A list of 259 species is presented, 30 of them are new to Lithuania. Arthonia helvola, Bacidina sulphurella, Candelariella lutella, Catillaria croatica, Cladonia conista, Gyalecta derivata, Lecanora quercicola, Leptosphaeria ramalinae, Strigula jamesii, Trichonectria rubefaciens, Verrucaria banatica, V. boblensis, V. christiansenii, V. illinoisensis, V. inornata, V. nigrofusca, V. trabicola, Zwackhiomyces diederichii are recorded for the first time in the Baltic countries. New lichens for Lithuania are: Bacidia incompta, Caloplaca crenulatella, C. pyracea, Catinaria atropurpurea, Lecanora populicola, L. semipallida, Mycobilimbia epixanthoides, Ramalina dilacerata, Verrucaria inaspecta, and new lichenicolous fungi are: Cladosporium licheniphilum, Stigmidium microspilum, Xenonectriella leptalea. Eighteen species included in the Lithuanian Red Data Book were recorded which is the highest number known for any studied area in Lithuania
Dismantling the treasured flagship lichen Sticta fuliginosa (Peltigerales) into four species in Western Europe
In the framework of a worldwide project on the phylogeny of the lichen genus Sticta, dedicated sampling was performed in four regions of Western Europe, roughly along an East-West line between N 48°02’ E 07°01’ and N 52°01’ W 09°30’, ranging from France/Vosges to Ireland/Kerry. Five clearly distinct ITS haplotypes were detected for isidia-producing species where only two were expected. Subtle anatomical and morphological characters, together with a strongly supported 4-loci molecular phylogeny, permit to distinguish, besides the easily recognized S. canariensis and S. limbata:
• the two « well-known » S. fuliginosa and S. sylvatica whose type collections have been carefully reassessed; the former is widespread in both hemispheres, while the latter is correctly identified only from continental Europe and the Andes in Colombia; the barcode ITS of S. fuliginosa differs by a single substitution from S. limbata (with a single exception), and the 4-loci phylogenetic tree does not resolve them as distinct lineages, most probably highlighting a very recent divergence and incomplete lineage sorting;
• three species that were formely included in S. fuliginosa: the resurrected S. ciliata Taylor, belonging to a complex group yet to be disentangled and occurring in the Neotropics, Africa, Macaronesia and Western Europe, and two species described as new for science, S. fuliginoides, found in continental Europe, the Canary Islands, eastern North America and Colombia, and S. atlantica only known from Ireland and the Azores archipelago. Molecular inferences demonstrate active divergence and dispersion within S. ciliata that may require recognition of further species.
Fresh material can be identified with a morphological and anatomical preliminary key provided here. We propose that the taxonomy of all lichen species be urgently reviewed in the light of molecular data in an evolutionary context, particularly those used as bioindicators of environmental change and woodland management