Taxonomy and phylogeny of three species in Perichaena sensu lato (Myxomycetes = Myxogastria) from China.

After Gulielmina was erected and Ophiotheca was resurrected based on some species originally included in Perichaena (Trichiaceae, Trichiales, Myxomyxetes), some specimens from the Herbarium of Fungi of Nanjing Normal University previously identified as Perichaena species were reexamined from morphological and two-gene (nuclear 18S rDNA and elongation factor-1 alpha) phylogenetic perspectives. In this study, two new myxomycete species, Gulielmina subreticulospora and Ophiotheca dictyospora, are described. Gulielmina subreticulospora shows the following character combination: branched plasmodiocarps, single peridium with circular protrusions in the inner surface, capillitium (2.4-)2.8-3.0(-3.4) µm in diameter, spores (7.4-)8.0-8.5(-9.0) µm in diameter and sub-reticulated. Ophiotheca dictyospora shows the following character combination: sessile sporocarps to short plasmodiocarps, single peridium with a densely irregular network and protrusions in the inner surface, capillitium (2.7-)3.5-5.0(-7.1) µm in diameter, uneven, decorated with spines of uneven size, spores (7.7-)8.2-8.6(-9.4) µm in diameter including obviously complete cristate reticulation with serrated edges, with deep and clear grids. Both new taxa were compared with related species and their genetic isolation was statistically tested. Moreover, a comprehensive morphological description and a detailed figure plate are provided for Perichaena verrucifera, and its phylogenetic position is determined.

Arcyria similaris: A new myxomycete species from China.

A new myxomycete species, Arcyria similaris, was reported herein. The specimens were found and collected in the field on dead bark from Jingangtai National Geopark in Henan Province of China. This species has distinct and unique morphological characteristics, including dark grayish olive sporothecae that fade to smoke gray with age, shallow saucer-shaped cups with marked reticulations and thick papillae on the inner surface, a netted capillitium with many bulges, uniformly marked with low, dense, and irregular reticulations, and spores (8.0-)9.3-10.1(-10.9) µm in diameter, marked with sparse small warts and grouped prominent warts. Apart from a comprehensive morphological study, partial sequences of the nuclear 18S rDNA and elongation factor-1 alpha (EF-1α) genes were also provided in this study. This new species was described and illustrated morphologically. The specimens are deposited in the Herbarium of Fungi of Nanjing Normal University (HFNNU).

Distribution, assembly, and interactions of soil microorganisms in the bright coniferous forest area of China's cold temperate zone.

The bright coniferous forest area in the cold temperate zone of China is a terrestrial ecosystem primarily dominated by low mountain Larix gmelinii trees. Limited information is available regarding the assembly mechanisms and interactions of microbial communities in the soil in this region. This study employed high-throughput techniques to obtain DNA from myxomycetes, bacteria, and fungi in the soil, evaluated their diversity in conjunction with environmental factors, associated them with the assembly process, and explored the potential interaction relationships between these microorganisms. The findings of our study showed that environmental factors had a more significant influence on the α and ß diversity of bacteria compared to myxomycetes and fungi. Microbial communities were influenced by environmental selection and geographical diffusion, although environmental selection appeared to have a more significant impact than geographical diffusion. Our study suggested that different microorganisms exhibited unique evolutionary patterns and may have different assembly modes within phylogenetic groups. Myxomycetes and fungi exhibited a similar assembly process that was mainly influenced by stochastic dispersal limitation and drift. In contrast, bacteria's assembly process was primarily influenced by stochastic drift and deterministic homogeneous selection. The community of myxomycetes and fungi is greatly influenced by spatial distribution and random events, while bacteria have a relatively stable population composition in specific regions and may also be subject to environmental constraints. Finally, this study revealed that Humicolopsis cephalosporioides, a fungus that exclusively resided in cold environments, may play a critical role as a keystone species in maintaining molecular ecological networks and was considered a core member of the microbiome.