Search

Tropical regions harbor rich biodiversity but are relatively poorly explored, especially in lesser known taxonomic groups, such as lichenized fungi. In addition, the identification of species is complicated by frequent occurrence of cryptic species and the plasticity of phenotypic features traditionally used to identify species. Here, we aim to explore species diversity and provide tools for accurate sample identification of the genus Parmotrema from rainforests in Thailand. We gathered a three-locus DNA sequence data set and this was analysed in phylogenetic and DNA barcode frameworks. While some morpho-species were recovered as monophyletic, others did not form monophyletic groups. Our study unmasked cryptic lineages in Parmotrema species distributed in the tropics and show that phenotype-based sample identification may underestimate species diversity in this group of lichens. Further, genetic distances based on ITS DNA sequences (i.e. DNA barcode approach) were shown to be a valuable tool for sample identification. In addition, our study highlights the need for taxonomic reexamination of the following phenotypically delimited species: P. corniculans, P. crinitum, P. haitiense, P. maclayanum, P. perlatum and P. subtinctorium. [ABSTRACT FROM AUTHOR]

Accurate specimen identification is challenging in groups with subtle or scarce taxonomically diagnostic characters, and the use of DNA barcodes can provide an effective means for consistent identification. Here, we investigate the utility of DNA barcode identification of species in a cosmopolitan genus of lichen-forming fungi, Parmelia (Parmeliaceae). Two hundred and two internal transcribed spacer (ITS) sequences generated from specimens collected from all continents, including Antarctica, were analysed, and DNA barcodes of 14 species of Parmelia s.s. are reported. Almost all species show a barcode gap. Overall, intraspecific divergence values were lower than the threshold previously established for Parmeliaceae. However, the mean and range were elevated by deep barcode divergences in three species, indicating the likely occurrence of overlooked specieslevel lineages. Here, we provide a DNA barcode reference library with well-identified specimens sampled worldwide and sequences from most of the type material to enable easy and fast accurate sample identification and to assist in uncovering overlooked species in Parmelia s.s. Further, our results confirm the efficiency of the ITS region in the identification of species of Parmelia s.s. [ABSTRACT FROM AUTHOR]

We used a genetic distance approach in conjunction with molecular phylogeny to establish species boundaries and detect cryptic lineages in the Parmotrema reticulatum – P. pseudoreticulatum complex. The phylogeny of specimens from a broad geographic distribution was reconstructed from the internal transcribed spacer region. Pairwise genetic distances were calculated and compared to an intraspecific range defined for the parmelioid lichens to circumscribe species-level groups. Our results showed that P. reticulatum and P. pseudoreticulatum are polyphyletic, being comprised of at least seven well-supported lineages. In contrast, the genetic distance approach revealed ten cryptic lineages within the P. reticulatum – P. pseudoreticulatum complex. Neither morphology nor geography was conclusive in attempting to corroborate these genetic lineages. However FST indices suggest significant genetic differentiation between these lineages. Our results suggest that the morphology-based circumscriptions underestimated species in Parmotrema and that, in some cases, genetic distances may be used as an additional tool to determine species boundaries in morphologically cryptic species complexes. The most significant contribution of the present study is the application of a fast and accurate method to identify problematic groups and candidate species using the ITS locus with a genetic distances approach. [ABSTRACT FROM AUTHOR]

Recently, the number of cryptic species known has increased considerably, showing that species diversity has in many cases been underestimated in the past. Parmelia sulcata is a widely distributed species and one of the most common taxa in temperate Europe. The first intra-specific molecular studies on P. sulcata showed an unexpectedly high genetic variability. In the present work, we study the biodiversity of this taxon including specimens from four continents and using three molecular markers (nuITS, nuIGS rDNA, and partial β-tubulin gene). Two monophyletic groups of P. sulcata were encountered; one of these is epitypified as P. sulcata s. str and the other one is segregated as the new cryptic species P. encryptata sp. nov. Issues surrounding the lectotypification of Parmelia sulcata have also been elucidated. [ABSTRACT FROM AUTHOR]

Morphological and phylogenetic relationships of the worldwide Mediterranean lichen forming fungus, Parmelina quercina, have been studied. Specimens from western Europe, western North America and southern Australia were analysed using molecular data (nuITS rDNA, nuLSU rDNA and mtSSU rDNA) and selected morphological features (upper cortex maculae, scanning electron microscopy examination of the epicortex, ascospores and conidia shape and size, and amphithecial retrorse rhizines). The results conclusively reveal that: (1) there is not one single species but four separate species in the Mediterranean or sub Mediterranean areas of the world. Parmelina quercina and Parmelina carporrhizans (Euroasiatic species), Parmelina coleae sp. nov. (North America) and Parmelina elixia sp. nov. (Australia); (2) largely debated P. carporrhizans is not a synonym of P. quercina but supported as a valid species circumscribed to Macaronesic relict sites; (3) the geographical isolation of the Australian population is correlated with a large genetic distance; (4) morphological characters (ascospores and conidial variability and thallus epicortex) correlate with the phylogenetic hypothesis; (5) the new or revalidated species within Parmelina quercina are not cryptic species but morphologically recognizable taxa. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 455–467. [ABSTRACT FROM AUTHOR]