Mycologia最新文献

Xerampelinae is a subsection composed of species of ectomycorrhizal fungi belonging to the hyperdiverse and cosmopolitan genus Russula (Russulales). Species of Xerampelinae are recognized by their fishy or shrimp odor, browning context, and a green reaction to iron sulfate. However, species delimitation has traditionally relied on morphology and analysis of limited molecular data. Prior taxonomic work in Xerampelinae has led to the description of as many as 59 taxa in Europe and 19 in North America. Here we provide the first multilocus phylogeny of European and North American members based on two nrDNA loci and two protein-coding genes. The resulting phylogeny supports the recognition of 17 species-rank Xerampelinae clades; however, higher species richness (~23) is suggested by a more inclusive nuclear rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) analysis. Phylogenetic and morphological analyses support three new species with restricted geographic distributions: R. lapponica, R. neopascua, and R. olympiana. We confirm that the European species R. subrubens is present in North America and the North American species R. serissima (previously known as R. favrei) is present in Europe. Most other Xerampelinae appear restricted to either North America or Eurasia, which indicates a high degree of regional endemism; this includes R. xerampelina, a name widely applied to North American taxa, but a species restricted to Eurasia.

Diverse communities of fungal endophytes reside in plant tissues, where they affect and are affected by plant physiology and ecology. For these intimate interactions to form and persist, endophytes and their host plants engage in intricate systems of communication. The conversation between fungal endophytes and plant hosts ultimately dictates endophyte community composition and function and has cascading effects on plant health and plant interactions. In this review, we synthesize our current knowledge on the mechanisms and strategies of communication used by endophytic fungi and their plant hosts. We discuss the molecular mechanisms of communication that lead to organ specificity of endophytic communities and distinguish endophytes, pathogens, and saprotrophs. We conclude by offering emerging perspectives on the relevance of plant-endophyte communication to microbial community ecology and plant health and function.

The entomopathogenic fungus Conoideocrella luteorostrata has recently been implicated in natural epizootics among exotic elongate hemlock scale (EHS) insects in Christmas tree farms in the eastern United States. Since 1913, C. luteorostrata has been reported from various plant feeding Hemiptera in the southeastern United States, but comprehensive morphological and phylogenetic studies of U.S. populations are lacking. The recovery of multiple strains of C. luteorostrata from mycosed EHS in North Carolina provided an opportunity to conduct pathogenicity assays and morphological and phylogenetic studies to investigate genus- and species-level boundaries among the Clavicipitaceae. Pathogenicity assays confirmed that C. luteorostrata causes mortality of EHS crawlers, an essential first step in developing this fungus as a biocontrol. Morphological studies revealed that conidia aligned with previous measurements of the Paecilomyces-like asexual state of C. luteorostrata, with conidiophore morphology consistent with historical observations. Additionally, a Hirsutella-like synanamorph was observed in select C. luteorostrata strains. In both a four-locus, 54-taxon Clavicipitaceae-wide phylogenetic analysis including D1-D2 domains of the nuclear 28S rRNA region (28S), elongation factor 1 alpha (EF1-α), DNA-directed RNA polymerase II subunit 1 (RPB1), and DNA-directed RNA polymerase II subunit 2 (RPB2) and a two-locus, 38-taxon (28S and EF1-α) phylogenetic analysis, all three Conoideocrella species were resolved as strongly supported monophyletic lineages across all loci and both methods (maximum likelihood and Bayesian inference) of phylogenetic inference except for 28S for C. tenuis. Despite the strong support for individual Conoideocrella species, none of the analyses supported the monophyly of Conoideocrella with the inclusion of Dussiella. Due to the paucity of RPB1 and RPB2 sequence data, EF1-α provided superior delimitation of intraspecies groupings for Conoideocrella and should be used in future studies. Further development of C. luteorostrata as a biocontrol against EHS will require additional surveys across diverse Hemiptera and expanded pathogenicity testing to clarify host range and efficacy of this fungus.

Members of Puccinia (Pucciniaceae, Pucciniales) are known as plant pathogens worldwide, which are characterized by their morphology, host association, and molecular data of various genes. In the present study, 10 specimens of Puccinia were collected from four herbaceous plants (Anaphalis hancockii, Anthriscus sylvestris, Halenia elliptica, and Pilea pumila) in China and identified based on morphology and phylogeny. As a result, 10 samples represent four undescribed species of Puccinia, viz., P. apdensia, P. decidua, P. dermatis, and P. lianchengensis, spp. nov. P. apdensia is characterized by its smooth teliospores with thickened apex. P. decidua represents the first Puccinia species inhabiting the host Anaphalis hancockii and is distinguished from the other Puccinia species by its telia and uredinia surrounded by the epidermis. P. dermatis from Halenia elliptica differs from the other Puccinia species on the host genus Halenia by the telia that have epidermis and teliospores with sparsely irregular granulated protrusions. P. lianchengensis is characterized by its teliospore surface with fishnet ornamentation and urediniospores without prominent caps. All of the new species are described and illustrated in this study.

Fungi are important decomposers of organic material, including animal waste. Ammonia and postputrefaction fungi grow in soil enriched in ammonium and nitrogen from carcasses. In 2014, we observed mushrooms fruiting on the flesh of a dead muskrat (Ondatra zibethicus) in an abandoned underground copper mine in southeastern New Brunswick, Canada. We placed an adult beaver (Castor canadensis) carcass near the muskrat to facilitate fungal colonization and fruiting. The beaver carcass was colonized by a variety of molds, especially Acaulium caviariforme. We observed mushrooms of an unidentified copriniid on the flesh 6 years and 9 months after carcass placement. Using morphological and molecular (nuclear internal transcribed spacer [nrITS]) data, we identified the mushrooms as Coprinopsis laanii, a rarely encountered species generally considered lignicolous. We discuss the role of C. laanii, and other postputrefaction fungi, in cave environments.

Plants belonging to the genera Astragalus, Oxytropis, Ipomoea, Sida, and Swainsona often contain the toxin swainsonine (SW) produced by an associated fungal symbiont. Consumption of SW-containing plants causes a serious neurological disorder in livestock, which can be fatal. In this study, a fungal endophyte, Alternaria section Undifilum, was identified in Astragalus garbancillo seeds, using polymerase chain reaction (PCR) followed by direct sequencing. In seeds, the SW concentrations were about 4 times higher than in other parts of the plant. Furthermore, microscopic examination demonstrated that the fungus mycelium grows inside the petioles and stems, on the outer surface and inside the mesocarp of the fruit, in the mesotesta and endotesta layers of the seed coat, and inside the endosperm of the seeds. Our results support the notion that the SW-producing fungus is vertically transmitted in the host plant A. garbancillo.

Most epiphytic lichens demonstrate high specificity to a habitat type, and sensitive hygrophilous species usually find shelter only in close-to-natural forest complexes. Some of them are considered as old-growth forest and/or long ecological continuity indicators. To evaluate general links between the narrow ecological range and physiological traits, two distinct sets of model lichens, i.e., old-growth forest (Cetrelia cetrarioides (Duby) W.L. Culb. & C.F. Culb., Lobaria pulmonaria (L.) Hoffm., Menegazzia terebrata (Hoffm.) A. Massal.), and generalist (Flavoparmelia caperata (L.) Hale, Hypogymnia physodes (L.) Nyl., Parmelia sulcata Taylor) ones, were examined in terms of sensitivity to long-term desiccation stress (1-, 2-, and 3-month) and photosynthesis activation rate upon rehydration. Desiccation tolerance and response rate to rehydration are specific to a given ecological set of lichens rather than to a particular species. Noticeable delayed and prompt recovery of high photosynthetic activity of photosystem II (PSII) characterize these sets, respectively. At the same time, although a decrease in the potential quantum yield of PSII in lichen thalli with a relative water content (RWC) at the level of 25% was observed, the efficiency remained at a very high level for all species, regardless of habitat preferences. Among the examined lichens, the fluorescence emission parameters for F. caperata were the fastest toward equilibrium upon rehydration, both after a shorter and a longer period of desiccation stress. In contrast to generalist lichens, retrieving of photosynthesis after 3-month desiccation failed in old-growth forest lichens. In the long term, prolonged rainless periods and unfavorable water balance in the environment predicted in the future may have a severely limiting effect on hygrophilous lichens during growing season (also in the sense of species associations) and, at the same time, promote the development of generalists.