Species delimitation of three species within the Russula subgenus Compacta in Korea: R. eccentrica, R. nigricans, and R. subnigricans

Morphological Characteristics and Phylogeny Reveal Six New Species in Russula Subgenus Russula (Russulaceae, Russulales) from Yanshan Mountains, North China

Species of the genus Russula are key components of ectomycorrhizal ecosystems worldwide, some of which are famous edible fungi. Although many new species have been described in China, their diversity in North China is still poorly known. Based on the morphology observation of specimens and molecular phylogenetic analyses, combined with the current classification frame of Russula, six new species of Russula subgenus Russula are proposed from the Yanshan Mountains in northern Beijing and northern Hebei Province of China in this study: viz. Russula miyunensis (subsection Chamaeleontinae), R. plana (subsection Chamaeleontinae), R. sinoparva (subsection Puellarinae), R. sinorobusta (subsection Puellarinae), R. subversatilis (subsection Roseinae), and R. yanshanensis (subsection Puellarinae). This is the first report of the species of Russula subgenus Russula from the Yanshan Mountains. This study enriches the species diversity of Russula in North China and provides new data support for the systematic study of Russula in subsequent research, including research and development on edibility.

Seven Unrecorded Indigenous Fungi from Mudeungsan National Park in Korea

Fungi act as important decomposers in the forest environment. They recycle essential nutrients, promote plant growth through mycorrhizal relationships, and act as food for small animals. Samples of 265 indigenous fungal species were collected from Mudeungsan National Park in 2020. These species were identified based on morphological, molecular, and phylogenetic analyses using the internal transcribed spacer (ITS), nuclear large subunit rRNA (LSU), and RNA polymerase II second largest subunit (rpb2) regions. Subsequently, seven species were identified as unrecorded species in Korea: Cordyceps cicadae, Dentocorticium bicolor, Hymenochaete nanospora, Physisporinus crataegi, Rigidoporus piceicola, Russula raoultii, and Scutellinia crinita. This study reveals their detailed macro- and microscopic morphological characteristics with phylogenetic trees to report them as unrecorded species in Korea.

Description of the Fifth New Species of Russula subsect. Maculatinae from Pakistan Indicates Local Diversity Hotspot of Ectomycorrhizal Fungi in Southwestern Himalayas

Russula subsect. Maculatinae is morphologically and phylogenetically well-defined lineage of ectomycorrhizal fungi associated with arctic, boreal, temperate and Mediterranean habitats of Northern Hemisphere. Based on phylogenetic distance among species, it seems that this group diversified relatively recently. Russula ayubiana sp. nov., described in this study, is the fifth in the group known from relatively small area of northern Pakistan situated in southwestern Himalayas. This is the highest known number of agaric lineage members from a single area in the world. This study uses available data about phylogeny, ecology, and climate to trace phylogenetic origin and ecological preferences of Maculatinae in southwestern Himalayas. Our results suggest that the area has been recently colonised by Maculatinae members migrating from various geographical areas and adapting to local conditions. We also discuss the perspectives and obstacles in research of biogeography and ecology, and we propose improvements that would facilitate the integration of ecological and biogeographical metadata from the future taxonomic studies of fungi in the region.

Taxonomic revision of Russula subsection Amoeninae from South Korea

RussulasubsectionAmoeninae is morphologically defined by a dry velvety pileus surface, a complete absence of cystidia with heteromorphous contents in all tissues, and spores without amyloid suprahilar spot. Thirty-four species within subsection Amoeninae have been published worldwide. Although most Russula species in South Korea have been assigned European or North American names, recent molecular studies have shown that Russula species from different continents are not conspecific. Therefore, the present study aims to: 1) define which species of RussulasubsectionAmoeninae occur on each continent using molecular phylogenetic analyses; 2) revise the taxonomy of Korean Amoeninae. The phylogenetic analyses using the internal transcribed spacer (ITS) and multilocus sequences showed that subsection Amoeninae is monophyletic within subgenus HeterophyllidiaesectionHeterophyllae. A total of 21 RussulasubsectionAmoeninae species were confirmed from Asia, Australia, Europe, North America, and Central America, and species from different continents formed separate clades. Three species were recognized from South Korea and were clearly separated from the European and North American species. These species are R.bella, also reported from Japan, a new species described herein, Russulaorientipurpurea, and a new species undescribed due to insufficient material.

Hypomyces pseudolactifluorum sp. nov. (Hypocreales: Hypocreaceae) on Russula sp. from Yunnan, PR China

Background

Hypomyces is a large genus of fungicolous fungi, parasitising the fruiting bodies of Agaricales, Boletales, Helotiales, Pezizales and Polyporales. Hypomyces currently comprises of 147 species widely distributed in Australia, China, France, Germany, Italy, Japan, North America, Sri Lanka, Thailand and UK. Amongst them, 28 species have been recorded in China.

New information

Hypomyces pseudolactifluorum sp. nov., growing on the fruiting bodies of Russula sp. in subsect. Lactarioideae and collected from Yunnan, China, is described with illustrations and molecular phylogenetic data (combined ITS, LSU, TEF1-α and RPB2 sequence dataset). The new species is characterised by semi-immersed to immersed perithecia and fusiform, apiculate and verrucose ascospores. We also review the species diversity of the genus Hypomyces in China.

The community composition variation of Russulaceae associated with the Quercus mongolica forest during the growing season at Wudalianchi City, China

BACKGROUND

Most species of the Russulaceae are ectomycorrhizal (ECM) fungi, which are widely distributed in different types of forest ecology and drive important ecological and economic functions. Little is known about the composition variation of the Russulaceae fungal community aboveground and in the root and soil during the growing season (June-October) from a Quercus mongolica forest. In this study, we investigated the changes in the composition of the Russulaceae during the growing season of this type of forest in Wudalianchi City, China.

METHODS

To achieve this, the Sanger sequencing method was used to identify the Russulaceae aboveground, and the high-throughput sequencing method was used to analyze the species composition of the Russulaceae in the root and soil. Moreover, we used the Pearson correlation analysis, the redundancy analysis and the multivariate linear regression analysis to analyze which factors significantly affected the composition and distribution of the Russulaceae fungal community.

RESULTS

A total of 56 species of Russulaceae were detected in the Q. mongolica forest, which included 48 species of Russula, seven species of Lactarius, and one species of Lactifluus. Russula was the dominant group. During the growing season, the sporocarps of Russula appeared earlier than those of Lactarius. The number of species aboveground exhibited a decrease after the increase and were significantly affected by the average monthly air temperature (r = -0.822, p = 0.045), average monthly relative humidity (r = -0.826, p = 0.043), monthly rainfall (r = 0.850, p = 0.032), soil moisture (r = 0.841, p = 0.036) and soil organic matter (r = 0.911, p = 0.012). In the roots and soils under the Q. mongolica forest, the number of species did not show an apparent trend. The number of species from the roots was the largest in September and the lowest in August, while those from the soils were the largest in October and the lowest in June. Both were significantly affected by the average monthly air temperature (r2 = 0.6083, p = 0.040) and monthly rainfall (r2 = 0.6354, p = 0.039). Moreover, the relative abundance of Russula and Lactarius in the roots and soils showed a linear correlation with the relative abundance of the other fungal genera.

Notes, outline and divergence times of Basidiomycota

The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.

A preliminary DNA barcode selection for the genus Russula (Russulales, Basidiomycota)

Russula is a worldwid genus which has a high species diversity . Aiming accurate and rapid species identification, candidate genes nLSU (28S), ITS, tef-1α, mtSSU, rpb1, and rpb2, were analysed as potential DNA barcodes. This analysis included 433 sequences from 38 well-circumscribed Russula species of eight subgenera. Two vital standards were analysed for success species identification using DNA barcodes, specifically inter- and intra-specific variations together with the success rates of PCR amplification and sequencing. Although the gap between inter- and intra-specific variations was narrow, ITS met the qualification standards for a target DNA barcode. Overlapping inter- and intra-specific pairwise distances were observed in nLSU, tef-1α, mtSSU, and rpb2. The success rates of PCR amplification and sequencing in mtSSU and rpb1 were lower than those of others. Gene combinations were also investigated for resolution of species recognition. ITS-rpb2 was suggested as the likely target DNA barcode for Russula, owing to the two viatal standards above. Since nLSU has the lowest minimum of inter-specific variation, and tef-1α has the highest overlap between intra- and inter-species variations among the candidate genes, they are disqualified from the selection for DNA barcode of Russula.

Characterization and comparative mitogenomic analysis of six newly sequenced mitochondrial genomes from ectomycorrhizal fungi (Russula) and phylogenetic analysis of the Agaricomycetes

In this study, the mitochondrial genomes of six Russula species were sequenced using next generation sequencing. The six mitogenomes were all composed of circular DNA molecules, with lengths ranging from 40,961 bp to 69,423 bp. The length and number of protein coding genes (PCGs), GC content, AT skew, and GC skew varied among the six mitogenomes. The increased number and total size of introns likely contributed to the size expansion of mitogenomes in some Russula species. Gene synteny analysis revealed some gene rearrangements among the six mitochondrial genomes. The nad4L gene had the lowest K2P genetic distance of the 15 core PCGs among the six Russula species, indicating that this gene was highly conserved. The Ka/Ks values for all 15 core PCGs were <1, suggesting that they were all subject to purifying selection. Phylogenetic analyses based on two gene datasets (15 core PCGs, and 15 core PCGs + rnl + rns) recovered identical and well-supported trees. In addition, cox1 was identified as a potential single-gene molecular marker for the phylogenetic analysis of relationships among Agaricomycetes species. This study provides the first report of mitogenomes from the Russulaceae family and facilitates the investigation of population genetics and evolution of other ectomycorrhizal fungi.

A Case of Mushroom Poisoning with Russula subnigricans: Development of Rhabdomyolysis, Acute Kidney Injury, Cardiogenic Shock, and Death

Mushroom exposures are increasing worldwide. The incidence and fatality of mushroom poisoning are reported to be increasing. Several new syndromes in mushroom poisoning have been described. Rhabdomyolytic mushroom poisoning is one of new syndromes. Russula subnigricans mushroom can cause delayed-onset rhabdomyolysis with acute kidney injury in the severely poisoned patient. There are few reports on the toxicity of R. subnigricans. This report represents the first record of R. subnigricans poisoning with rhabdomyolysis in Korea, describing a 51-year-old man who suffered from rhabdomyolysis, acute kidney injury, severe hypocalcemia, respiratory failure, ventricular tachycardia, cardiogenic shock, and death. Mushroom poisoning should be considered in the evaluation of rhabdomyolysis of unknown cause. Furthermore, R. subnigricans should be considered in the mushroom poisoning with rhabdomyolysis.

Recent advances in population genetics of ectomycorrhizal mushrooms Russula spp

The mushroom genus Russula is among the largest and morphologically most diverse basidiomycete genera in the world. They are broadly distributed both geographically and ecologically, forming ectomycorrhizal relationships with a diversity of plants. Aside from their ecological roles, some Russula species are gourmet mushrooms. Therefore, understanding their population biology and fundamental life history processes are important for illustrating their ecological roles and for developing effective conservation and utilization strategies. Here, we review recent population genetic and molecular ecological studies of Russula. We focus on issues related to genet sizes, modes of reproduction, population structures, and roles of geography on their genetic relationships. The sampling strategies, molecule markers, and analytical approaches used in these studies will also be discussed. Our review suggests that in Russula, genets are typically small, local recombination is frequent, and that long-distance spore dispersal is relatively uncommon. We finish by discussing several long-standing issues as well as future trends with regard to life history and evolution of this important group of mushrooms.