Implications of molecular characters for the phylogeny of the Microbotryaceae (Basidiomycota: Urediniomycetes)

BACKGROUND: Anther smuts of the basidiomycetous genus Microbotryum on Caryophyllaceae are important model organisms for many biological disciplines. Members of Microbotryum are most commonly found parasitizing the anthers of host plants in the family Caryophyllaceae, however they can also be found on the anthers of members of the Dipsacaceae, Lamiaceae, Lentibulariaceae, and Portulacaceae. Additionally, some members of Microbotryum can be found infecting other organs of mainly Polygonaceae hosts. Based on ITS nrDNA sequences of members of almost all genera in Microbotryaceae, this study aims to resolve the phylogeny of the anther smuts and their relationship to the other members of the family of plant parasites. A multiple analysis strategy was used to correct for the effects of different equally possible ITS sequence alignments on the phylogenetic outcome, which appears to have been neglected in previous studies. RESULTS: The genera of Microbotryaceae were not clearly resolved, but alignment-independent moderate bootstrap support was achieved for a clade containing the majority of the Microbotryum species. The anther parasites appeared in two different well-supported lineages whose interrelationship remained unresolved. Whereas bootstrap support values for some clades were highly vulnerable to alignment conditions, other clades were more robustly supported. The differences in support between the different alignments were much larger than between the phylogenetic optimality criteria applied (maximum parsimony and maximum likelihood). CONCLUSION: The study confirmed, based on a larger dataset than previous work, that the anther smuts on Caryophyllaceae are monophyletic and that there exists a native North American group that diverged from the European clade before the radiation of the European species. Also a second group of anther smuts was revealed, containing parasites on Dipsacaceae, Lamiaceae, and Lentibulariaceae. At least the majority of the parasites of Asteraceae appeared as a monophylum, but delimitations of some species in this group should be reconsidered. Parasitism on Polygonaceae is likely to be the ancestral state for the Microbotryaceae on Eudicot hosts

Phylogenetic relationships in Cortinarius, section Calochroi, inferred from nuclear DNA sequences

<p>Abstract</p> <p>Background</p> <p>Section <it>Calochroi </it>is one of the most species-rich lineages in the genus <it>Cortinarius </it>(Agaricales, Basidiomycota) and is widely distributed across boreo-nemoral areas, with some extensions into meridional zones. Previous phylogenetic studies of <it>Calochroi </it>(incl. section <it>Fulvi</it>) have been geographically restricted; therefore, phylogenetic and biogeographic relationships within this lineage at a global scale have been largely unknown. In this study, we obtained DNA sequences from a nearly complete taxon sampling of known species from Europe, Central America and North America. We inferred intra- and interspecific phylogenetic relationships as well as major morphological evolutionary trends within section <it>Calochroi </it>based on 576 ITS sequences, 230 ITS + 5.8S + D1/D2 sequences, and a combined dataset of ITS + 5.8S + D1/D2 and RPB1 sequences of a representative subsampling of 58 species.</p> <p>Results</p> <p>More than 100 species were identified by integrating DNA sequences with morphological, macrochemical and ecological data. <it>Cortinarius </it>section <it>Calochroi </it>was consistently resolved with high branch support into at least seven major lineages: <it>Calochroi</it>, <it>Caroviolacei</it>, <it>Dibaphi</it>, <it>Elegantiores</it>, <it>Napi</it>, <it>Pseudoglaucopodes </it>and <it>Splendentes</it>; whereas <it>Rufoolivacei </it>and <it>Sulfurini </it>appeared polyphyletic. A close relationship between <it>Dibaphi</it>, <it>Elegantiores</it>, <it>Napi </it>and <it>Splendentes </it>was consistently supported. Combinations of specific morphological, pigmentation and molecular characters appear useful in circumscribing clades.</p> <p>Conclusion</p> <p>Our analyses demonstrate that <it>Calochroi </it>is an exclusively northern hemispheric lineage, where species follow their host trees throughout their natural ranges within and across continents. Results of this study contribute substantially to defining European species in this group and will help to either identify or to name new species occurring across the northern hemisphere. Major groupings are in partial agreement with earlier morphology-based and molecular phylogenetic hypotheses, but some relationships were unexpected, based on external morphology. In such cases, their true affinities appear to have been obscured by the repeated appearance of similar features among distantly related species. Therefore, further taxonomic studies are needed to evaluate the consistency of species concepts and interpretations of morphological features in a more global context. Reconstruction of ancestral states yielded two major evolutionary trends within section <it>Calochroi</it>: (1) the development of bright pigments evolved independently multiple times, and (2) the evolution of abruptly marginate to flattened stipe bulbs represents an autapomorphy of the <it>Calochroi </it>clade.</p

An overview of the higher level classification of Pucciniomycotina based on combined analyses of nuclear large and small subunit rDNA sequences

Mycologia, Vol. 98, nº6In this study we provide a phylogenetically based introduction to the classes and orders of Pucciniomycotina (5Urediniomycetes), one of three subphyla of Basidiomycota. More than 8000 species of Pucciniomycotina have been described including putative saprotrophs and parasites of plants, animals and fungi. The overwhelming majority of these(,90%) belong to a single order of obligate plant pathogens, the Pucciniales (5Uredinales), or rust fungi. We have assembled a dataset of previously published and newly generated sequence data from two nuclear rDNA genes (large subunit and small subunit) including exemplars from all known major groups in order to test hypotheses about evolutionary relationships among the Pucciniomycotina. The utility of combining nuc-lsu sequences spanning the entire D1-D3 region with complete nuc-ssu sequences for resolution and support of nodes is discussed. Our study confirms Pucciniomycotina as a monophyletic group of Basidiomycota. In total our results support eight major clades ranked as classes (Agaricostilbomycetes, Atractiellomycetes, Classiculomycetes,Cryptomycocolacomycetes,Cystobasidiomycetes, Microbotryomycetes,Mixiomycetes and Pucciniomycetes) and 18 orders

Sebacinales Everywhere: Previously Overlooked Ubiquitous Fungal Endophytes

Inconspicuous basidiomycetes from the order Sebacinales are known to be involved in a puzzling variety of mutualistic plant-fungal symbioses (mycorrhizae), which presumably involve transport of mineral nutrients. Recently a few members of this fungal order not fitting this definition and commonly referred to as ‘endophytes’ have raised considerable interest by their ability to enhance plant growth and to increase resistance of their host plants against abiotic stress factors and fungal pathogens. Using DNA-based detection and electron microscopy, we show that Sebacinales are not only extremely versatile in their mycorrhizal associations, but are also almost universally present as symptomless endophytes. They occurred in field specimens of bryophytes, pteridophytes and all families of herbaceous angiosperms we investigated, including liverworts, wheat, maize, and the non-mycorrhizal model plant Arabidopsis thaliana. They were present in all habitats we studied on four continents. We even detected these fungi in herbarium specimens originating from pioneering field trips to North Africa in the 1830s/40s. No geographical or host patterns were detected. Our data suggest that the multitude of mycorrhizal interactions in Sebacinales may have arisen from an ancestral endophytic habit by specialization. Considering their proven beneficial influence on plant growth and their ubiquity, endophytic Sebacinales may be a previously unrecognized universal hidden force in plant ecosystems

Tracking the evolutionary history of Cortinarius species in section Calochroi, with transoceanic disjunct distributions

<p>Abstract</p> <p>Background</p> <p><it>Cortinarius </it>species in section <it>Calochroi </it>display local, clinal and circumboreal patterns of distribution across the Northern Hemisphere where these ectomycorrhizal fungi occur with host trees throughout their geographical range within a continent, or have disjunct intercontinental distributions, the origins of which are not understood. We inferred evolutionary histories of four species, 1) <it>C</it>. <it>arcuatorum</it>, 2) <it>C. aureofulvus</it>, 3) <it>C</it>. <it>elegantior </it>and 4) <it>C. napus</it>, from populations distributed throughout the Old World, and portions of the New World (Central- and North America) based on genetic variation of 154 haplotype internal transcribed spacer (ITS) sequences from 83 population samples. By describing the population structure of these species across their geographical distribution, we attempt to identify their historical migration and patterns of diversification.</p> <p>Results</p> <p>Models of population structure from nested clade, demographic and coalescent-based analyses revealed genetically differentiated and geographically structured haplotypes in <it>C</it>. <it>arcuatorum </it>and <it>C</it>. <it>elegantior</it>, while <it>C</it>. <it>aureofulvus </it>showed considerably less population structure and <it>C. napus </it>lacked sufficient genetic differentiation to resolve any population structure. Disjunct populations within <it>C</it>. <it>arcuatorum, C. aureofulvus </it>and <it>C</it>. <it>elegantior </it>show little or no morphological differentiation, whereas in <it>C. napus </it>there is a high level of homoplasy and phenotypic plasticity for veil and lamellae colour. The ITS sequences of the type specimens of <it>C. albobrunnoides </it>and <it>C. albobrunnoides </it>var. <it>violaceovelatus </it>were identical to one another and are treated as one species with a wider range of geographic distribution under <it>C. napus</it>.</p> <p>Conclusions</p> <p>Our results indicate that each of the <it>Calochroi </it>species has undergone a relatively independent evolutionary history, hypothesised as follows: 1) a widely distributed ancestral population of <it>C</it>. <it>arcuatorum </it>diverged into distinctive sympatric populations in the New World; 2) two divergent lineages in <it>C</it>. <it>elegantior </it>gave rise to the New World and Old World haplotypes, respectively; and 3) the low levels of genetic divergence within <it>C</it>. <it>aureofulvus </it>and <it>C</it>. <it>napus </it>may be the result of more recent demographic population expansions. The scenario of migration via the Bering Land Bridge provides the most probable explanation for contemporaneous disjunct geographic distributions of these species, but it does not offer an explanation for the low degree of genetic divergence between populations of <it>C. aureofulvus </it>and <it>C. napus</it>. Our findings are mostly consistent with the designation of New World allopatric populations as separate species from the European counterpart species <it>C. arcuatorum </it>and <it>C. elegantior</it>. We propose the synonymy of <it>C. albobrunnoides</it>, <it>C. albobrunnoides </it>var. <it>violaceovelatus </it>and <it>C. subpurpureophyllus </it>var. <it>sulphureovelatus </it>with <it>C. napus</it>. The results also reinforce previous observations that linked <it>C. arcuatorum </it>and <it>C. aureofulvus </it>displaying distributions in parts of North America and Europe. Interpretations of the population structure of these fungi suggest that host tree history has heavily influenced their modern distributions; however, the complex issues related to co-migration of these fungi with their tree hosts remain unclear at this time.</p

RESUPINATE BASIDIOMYCETEN AUS RES. FOR SAN RAMON

RESUPINATE BASIDIOMYCETEN AUS RES. FOR SAN RAMO