Abstract. To determine whether host species influence the composition of fungal communities, the ascomycetes and basidiomycetes present on three tree species (Prioria copaifera (Fabaceae), Quararibea asterolepis (Bombacaceae), and Trichilia tuberculata (Meliaceae)) were sampled on the 50-ha Forest Dynamics Project plot in lowland moist tropical forest on Barro Colorado Island, Panama. The most abundant fungal morphotypes of both ascomycetes and basidiomycetes were generalists found on all three hosts, but detrended correspondence analysis revealed distinct differences in fungal community composition among host trees. These differences among hosts were constant across census years. Randomization tests revealed that there were significantly fewer hostgeneralist fungi than expected for ascomycetes but not for basidiomycetes. These results indicate that host composition plays a role in structuring both ascomycete and basidiomycete fungal communities, but that the most successful fungal morphotypes are capable of colonizing multiple host species.
Jahnulales is an order of freshwater, lignicolous, bitunicate ascomycetes characterized by wide (10–40 μm), brown, septate hyphae, stalked and (or) sessile ascomata, ascomal walls of 2–6 layers of large cells, and 1-septate ascospores. A variety of ascospore modifications are represented among the species in the order, including wall roughening, gelatinous sheaths, appendages and (or) pads, and apical caps or spines. To clarify generic boundaries and phylogenetic relationships within the Jahnulales and to assess the taxonomic significance of various morphological characters, a molecular study was carried out using 18S and 28S rDNA sequence data from 15 species representing the four genera in the order. In addition, Brachiosphaera tropicalis Nawawi and Xylomyces chlamydosporus Goos, R.D. Brooks & Lamore, two mitosporic species that co-occur with Jahnula Kirschst., species and have wide (>10 μm), brown, septate hyphae were included in the study to determine whether these species are members of this order. Maximum likelihood analyses confirmed the monophyly of the Jahnulales and resolved four clades. Two robustly supported clades comprise the genera Aliquandostipite Inderb. and Megalohypha A. Ferrer & Shearer. A third well-supported clade encompassed species of Brachiosphaera , Jahnula , and Xylomyces . The fourth clade contained isolates of the type species of the genus Jahnula, Jahnula aquatica (Plöttn. & Kirschst.) Kirschst., and two other members of this genus, but this clade was weakly supported. Our data suggest that the presence of very wide, brown, septate hyphae is an important character defining the Jahnulales. Based on molecular and morphological data, we propose the transfer of Jahnula siamensiae Sivichai & E.B.G. Jones and Patescospora separans Abdel-Wahab & El-Shar. to Aliquandostipite and emend the description of the Jahnulales.
Two new genera are established in the Dothideomycetes based on morphological and molecular data (SSU and LSU nuclear ribosomal sequences) to accommodate four ascomycete species collected from woody debris submerged in freshwater habitats. The genus Minutisphaera is represented by a single species, M. fimbriatispora, which was collected from freshwater habitats in temperate forests in North America. It has small, superficial, brown, subglobose, papillate pseudothecia with dark, irregularly twisted hairs around the papillae, fissitunicate asci, septate pseudoparaphyses, and hyaline, one-septate ascospores surrounded by a gelatinous sheath and having spine-like appendages radiating around the ascospore at the septum. Minutisphaera formed a strongly supported clade with Farlowiella carmichaeliana. The second genus, Natipusilla, contains three new species, N. decorospora, N. limonensis and N. naponensis, which were collected from Central and South America. Natipusilla is characterized by small, superficial, light-colored, globose pseudothecia, fissitunicate asci, few or no pseudoparaphyses, and hyaline, one-septate to tardily two- or three-septate ascospores with or without a gelatinous sheath. The three Natipusilla species form a well supported clade, but their relationship to other members of the Dothideomycetes remains unclear.
Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface.
With the increasing democratization of high-throughput sequencing (HTS) technologies, along with the concomitant increase in sequence yield per dollar, many researchers are exploring HTS for microbial community ecology. Many elements of experimental design can drastically affect the final observed community structure, notably the choice of primers for amplification prior to sequencing. Some targeted microbes can fail to amplify due to primer-targeted sequence divergence and be omitted from obtained sequences, leading to differences among primer pairs in the sequenced organisms even when targeting the same community. This potential source of taxonomic bias in HTS makes it prudent to investigate how primer choice will affect the sequenced community prior to investing in a costly community-wide sequencing effort. Here, we use Fluidigm's microfluidic Access Arrays (IFC) followed by Illumina(®) MiSeq Nano sequencing on a culture-derived local mock community to demonstrate how this approach allows for a low-cost combinatorial investigation of primer pairs and experimental samples (up to 48 primer pairs and 48 samples) to determine the most effective primers that maximize obtained communities whilst minimizing taxonomic biases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.