39 research outputs found
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Sequestrate fungi from Patagonian Nothofagus forests: Cystangium (Russulaceae, Basidiomycota)
Six species of Cystangium, a genus of
sequestrate taxa related to Russula, were collected
in Patagonia (Argentina and Chile) during autumn
2001. Two species, C. depauperatum Singer & A.H.
Sm. and C. nothofagi (E. Horak) Trappe, Castellano &
T. Lebel, were already known from this region, while
four new species, C. domingueziae, C. gamundiae, C.
grandihyphatum and C. longisterigmatum, are described,
illustrated and a key to the species is
provided. In addition, sequences of the ITS (rDNA)
region were obtained to explore the phylogenetic
relationships of our South American Cystangium
species.This is the publisher’s final pdf. The article is copyrighted by the Mycological Society of America and published by Allen Press Inc. It can be found at: http://www.mycologia.org/.Keywords: Russulales, Mycorrhiza, Truffle-like fungi, Hypogeous fung
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Historical Biogeography and Diversification of Truffles in the Tuberaceae and Their Newly Identified Southern Hemisphere Sister Lineage
Truffles have evolved from epigeous (aboveground) ancestors in nearly every major lineage of fleshy fungi. Because accelerated rates of morphological evolution accompany the transition to the truffle form, closely related epigeous ancestors remain unknown for most truffle lineages. This is the case for the quintessential truffle genus Tuber, which includes species with socio-economic importance and esteemed culinary attributes. Ecologically, Tuber spp. form obligate mycorrhizal symbioses with diverse species of plant hosts including pines, oaks, poplars, orchids, and commercially important trees such as hazelnut and pecan. Unfortunately, limited geographic sampling and inconclusive phylogenetic relationships have obscured our understanding of their origin, biogeography, and diversification. To address this problem, we present a global sampling of Tuberaceae based on DNA sequence data from four loci for phylogenetic inference and molecular dating. Our well-resolved Tuberaceae phylogeny shows high levels of regional and continental endemism. We also identify a previously unknown epigeous member of the Tuberaceae - the South American cup-fungus Nothojafnea thaxteri (E.K. Cash) Gamundi. Phylogenetic resolution was further improved through the inclusion of a previously unrecognized Southern hemisphere sister group of the Tuberaceae. This morphologically diverse assemblage of species includes truffle (e.g. Gymnohydnotrya spp.) and non-truffle forms that are endemic to Australia and South America. Southern hemisphere taxa appear to have diverged more recently than the Northern hemisphere lineages. Our analysis of the Tuberaceae suggests that Tuber evolved from an epigeous ancestor. Molecular dating estimates Tuberaceae divergence in the late Jurassic (~156 million years ago), with subsequent radiations in the Cretaceous and Paleogene. Intra-continental diversification, limited long-distance dispersal, and ecological adaptations help to explain patterns of truffle evolution and biodiversity
Morphological and molecular characterization of selected Ramaria mycorrhizae
Ramaria species are conspicuous mycorrhizal symbionts of conifers in the Pacific Northwest. Here we collected and identified sporocarps and associated ectomycorrhizae of Ramaria acrisiccescens Marr & Stuntz, R. cyaneigranosa Marr & Stuntz, R. sandracina Marr & Stuntz, R. celerivirescens Marr & Stuntz, and R. flavobrunnescens var. aromatica Marr & Stuntz. An internal transcribed spacer (ITS)- restriction fragment length polymorphism pattern was observed for each of the Ramaria species and used as a diagnostic tool to support the identification of mycorrhizae occurring in mats below the sporocarps. We provide a description of the ectomycorrhizae of Ramaria, which exhibit similar macro- and microscopic characteristics such as ramification pattern, coloration, abundance of mycelial strands and emanating hyphae, mantle morphology and chemical reactions of mantle and mycelial strands with KOH, Fe SO4 and Melzer´s reagent. Sequences of the ITS region for each of the species are deposited in the Gen Bank.Fil: Nouhra, Eduardo Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Horton, Thomas R.. College of Enviromental Science and Forestry; Estados UnidosFil: Cazares, Efren. State University of Oregon; Estados UnidosFil: Castellano, Michael. United State Department of Agriculture; Estados Unido
Revisiting the secotioid and gasteroid Cortinarius species from Patagonia
The diversity of secotioid taxa within Cortinarius in the Nothofagaceae forests of Patagonia has drawn attention of mycologists during the last century. In the Patagonian region of Argentina and Chile Cortinarius is among the most diverse and abundant genera of ectomycorrhizal fungi with at least 240 species from the Andean mountains. Secotioid and gasteroid forms were until recently considered primarily within Thaxterogaster, resulting in a confusing intrageneric classification system. Moser and Horak suggested that Thaxterogaster was nested within Cortinarius. The modern molecular analysis of Peintner et al. investigated the multiple origins of sequestrate taxa related to Cortinarius and consequently synonymized Thaxterogaster to Cortinarius. Subsequent molecular phylogenies have resolved the polyphyletic nature of Thaxterogaster and other "cortinarioid" taxa within Cortinarius but have also highlighted the fact that most sequestrate Patagonian taxa lack molecular data. Original descriptions of these fungi are available mostly in German and Spanish and the interpretations of morphological structures are outdated considering the current state of knowledge about sporemorphology and ontogeny. For example, verrucae on spores were illustrated as globose structures whereas SEM shows that they are complex conical structures that are sometimes interconnected by reticula or sub-reticula. External walls or episporia were sometimes pictured in original descriptions but our analyses suggest that these may have been optical illusions due to non-DIC microscopy. Recently, the incorrect interpretation of this episporium in the "cortinariod" fungi was found to be a misleading character. Despite recent advances in Cortinarius systematics, the current classification, diversity andecology of secotioid and hypogeous "cortinarioid" fungi in the Nothofagaceae forests of southern South America remains unclear. The objective of this study is to update descriptions with diagnostic characters, including color photos of basidiomata, SEM images of spores, and ITS sequence data to clarify the biodiversity of these fungi in Patagonia. Original descriptions of secotioid and gasteroid taxa were also revised and translated to English. Our analyses based on SEM and ITS rDNA resolves at least 15 species with names that need to be considered as synonyms. The use of these tools combined with an extensive database of described species also facilitated the recognition of several new and undescribed Patagonian species. Analysis of spore ultrastructure across many specimens clearly shows that sequestrate species of Cortinarius always lack a perisporium. It also indicates that there is a transition process in shape and ornamentation that occurs in taxa as they switch from ballistosporic tostatimosporic spore dispersal.Fil: Nouhra, Eduardo Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Kuhar, José Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Provincia del Chubut. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Truong, Camille. Universidad Nacional Autónoma de México; MéxicoFil: Mujic, Alija. University of Florida; Estados UnidosFil: Healy, R.. University of Florida; Estados UnidosFil: Smith, M. E.. University of Florida; Estados Unidos11th International Mycological Congress: Mycological Discoveries for a Better WorldSan Juan de Puerto RicoPuerto RicoInternational Mycological AssociationMycological Society of Americ