Assembly collapsing versus heterozygosity oversizing: detection of homokaryotic and heterokaryotic Laccaria trichodermophora strains by hybrid genome assembly.

Genome assembly and annotation using short-paired reads is challenging for eukaryotic organisms due to their large size, variable ploidy and large number of repetitive elements. However, the use of single-molecule long reads improves assembly quality (completeness and contiguity), but haplotype duplications still pose assembly challenges. To address the effect of read length on genome assembly quality, gene prediction and annotation, we compared genome assemblers and sequencing technologies with four strains of the ectomycorrhizal fungus Laccaria trichodermophora. By analysing the predicted repertoire of carbohydrate enzymes, we investigated the effects of assembly quality on functional inferences. Libraries were generated using three different sequencing platforms (Illumina Next-Seq, Mi-Seq and PacBio Sequel), and genomes were assembled using single and hybrid assemblies/libraries. Long reads or hybrid assemby resolved the collapsing of repeated regions, but the nuclear heterozygous versions remained unresolved. In dikaryotic fungi, each cell includes two nuclei and each nucleus has differences not only in allelic gene version but also in gene composition and synteny. These heterokaryotic cells produce fragmentation and size overestimation of the genome assembly of each nucleus. Hybrid assembly revealed a wider functional diversity of genomes. Here, several predicted oxidizing activities on glycosyl residues of oligosaccharides and several chitooligosaccharide acetylase activities would have passed unnoticed in short-read assemblies. Also, the size and fragmentation of the genome assembly, in combination with heterozygosity analysis, allowed us to distinguish homokaryotic and heterokaryotic strains isolated from L. trichodermophora fruit bodies.

Broadening the Knowledge of Mexican Boletes: Addition of a New Genus, Seven New Species, and Three New Combinations.

Boletes are one of the most common groups of fungi in temperate, subtropical, and tropical ecosystems. In Mexico, the northern region has mainly been explored in terms of bolete diversity. This study describes a new genus and seven new species based on macromorphological, micromorphological, molecular, phylogenetic, and ecological data. Garcileccinum gen. nov. is typified with G. salmonicolor based on multigene phylogenetic analysis of nrLSU, RPB2, and TEF1, and it is closely related to Leccinum and Leccinellum. Garcileccinum viscosum and G. violaceotinctum are new combinations. Boletellus minimatenebris (ITS, nrLSU, and RPB2), Cacaoporus mexicanus (RPB2 and ATP6), Leccinum oaxacanum, Leccinum juarenzense (nrLSU, RPB2, and TEF1), Tylopilus pseudoleucomycelinus (nrLSU and RPB2), and Xerocomus hygrophanus (ITS, nrLSU, and RPB2) are described as new species. Boletus neoregius is reclassified as Pulchroboletus neoregius comb. nov. based on morphological and multigene phylogenetic analysis (ITS and nrLSU), and its geographic distribution is extended to Central Mexico, since the species was only known from Costa Rica. Furthermore, T. leucomycelinus is a new record from Mexico. This study contributes to increasing our knowledge of boletes and expands the diversity found in Mexican forests.

Alternatives for mushroom poisoning timely care in Mexico and Central America.

BACKGROUND: In countries where the consumption of mushrooms is common, hundreds of mushroom poisonings occur every year, which represents a public health problem. In Mexico, mushroom poisoning is classified as a non-bacterial gastrointestinal poisoning, which prevents timely care. OBJECTIVE: To create a free-access platform that synthesizes and standardizes the information on mycetism cases and offers tools for diagnosis and timely treatment. MATERIAL AND METHODS: In locations where cases of mycetism have occurred, information was obtained on the fungi involved, the poisonings that occurred, care protocols, and sample processing. RESULTS: Records were generated that synthesize and describe the types of mycetism with the highest probability of occurrence in Mexico. Therein, the biological characteristics of fungi, the symptoms they cause and their treatment are described. A protocol proposal for patient care and for the processing of biological samples is presented. Finally, a form is included to collect information on cases of poisoning. CONCLUSIONS: Systematized and analyzed information on mycetism allows to simplify its diagnosis, attention and treatment. The protocols for clinical care and sample processing are the basis for generating strategies that prevent deaths due to mycetism.

ANTECEDENTES: En países donde el consumo de hongos es frecuente ocurren cientos de casos de micetismos al año, por lo que representan un problema de salud pública. En México, los micetismos son clasificados como una intoxicación gastrointestinal de tipo no bacteriano, lo que impide su atención oportuna. OBJETIVO: Crear una plataforma de libre acceso que sintetice y estandarice la información de los casos de micetismos y ofrezca herramientas para su diagnóstico y tratamiento oportuno. MATERIAL Y MÉTODOS: En localidades donde han ocurrido casos de micetismos se obtuvo información sobre los hongos involucrados, las intoxicaciones ocurridas, protocolos de atención y procesamiento de muestras. RESULTADOS: Se generaron cédulas que sintetizan y describen las intoxicaciones por hongos con mayor probabilidad de ocurrencia en México. En ellas se describen las características biológicas de los hongos, síntomas que provocan y su tratamiento. Se presenta una propuesta de protocolo para la atención del paciente y para el procesamiento de muestras biológicas. Por último, se incluye un formulario para recopilar información sobre los casos de intoxicaciones. CONCLUSIONES: La información sistematizada y analizada sobre los micetismos permite simplificar su diagnóstico, atención y tratamiento. Los protocolos para la atención clínica y el procesamiento de muestras son la base para generar estrategias que eviten decesos por micetismo.

Alternativas para la atención oportuna de las intoxicaciones por consumo de hongos en México y Centroamérica / Alternatives for mushroom poisoning timely care in Mexico and Central America

Resumen Antecedentes: En países donde el consumo de hongos es frecuente ocurren cientos de casos de micetismos al año, por lo que representan un problema de salud pública. En México, los micetismos son clasificados como una intoxicación gastrointestinal de tipo no bacteriano, lo que impide su atención oportuna. Objetivo: Crear una plataforma de libre acceso que sintetice y estandarice la información de los casos de micetismos y ofrezca herramientas para su diagnóstico y tratamiento oportuno. Material y métodos: En localidades donde han ocurrido casos de micetismos se obtuvo información sobre los hongos involucrados, las intoxicaciones ocurridas, protocolos de atención y procesamiento de muestras. Resultados: Se generaron cédulas que sintetizan y describen las intoxicaciones por hongos con mayor probabilidad de ocurrencia en México. En ellas se describen las características biológicas de los hongos, síntomas que provocan y su tratamiento. Se presenta una propuesta de protocolo para la atención del paciente y para el procesamiento de muestras biológicas. Por último, se incluye un formulario para recopilar información sobre los casos de intoxicaciones. Conclusiones: La información sistematizada y analizada sobre los micetismos permite simplificar su diagnóstico, atención y tratamiento. Los protocolos para la atención clínica y el procesamiento de muestras son la base para generar estrategias que eviten decesos por micetismo.

Abstract Background: In countries where the consumption of mushrooms is common, hundreds of mushroom poisonings occur every year, which represents a public health problem. In Mexico, mushroom poisoning is classified as a non-bacterial gastrointestinal poisoning, which prevents timely care. Objective: To create a free-access platform that synthesizes and standardizes the information on mycetism cases and offers tools for diagnosis and timely treatment. Material and methods: In locations where cases of mycetism have occurred, information was obtained on the fungi involved, the poisonings that occurred, care protocols, and sample processing. Results: Infographics were generated that synthesize and describe the types of mycetism with the highest probability of occurrence in Mexico. Therein, the biological characteristics of fungi, the symptoms they cause and their treatment are described. A protocol proposal for patient care and for the processing of biological samples is presented. Finally, a form is included to collect information on cases of poisoning. Conclusions: Systematized and analyzed information on mycetism allows to simplify its diagnosis, attention and treatment. The protocols for clinical care and sample processing are the basis for generating strategies that prevent deaths due to mycetism.

Metabarcoding of soil environmental DNA to estimate plant diversity globally.

Introduction: Traditional approaches to collecting large-scale biodiversity data pose huge logistical and technical challenges. We aimed to assess how a comparatively simple method based on sequencing environmental DNA (eDNA) characterises global variation in plant diversity and community composition compared with data derived from traditional plant inventory methods. Methods: We sequenced a short fragment (P6 loop) of the chloroplast trnL intron from from 325 globally distributed soil samples and compared estimates of diversity and composition with those derived from traditional sources based on empirical (GBIF) or extrapolated plant distribution and diversity data. Results: Large-scale plant diversity and community composition patterns revealed by sequencing eDNA were broadly in accordance with those derived from traditional sources. The success of the eDNA taxonomy assignment, and the overlap of taxon lists between eDNA and GBIF, was greatest at moderate to high latitudes of the northern hemisphere. On average, around half (mean: 51.5% SD 17.6) of local GBIF records were represented in eDNA databases at the species level, depending on the geographic region. Discussion: eDNA trnL gene sequencing data accurately represent global patterns in plant diversity and composition and thus can provide a basis for large-scale vegetation studies. Important experimental considerations for plant eDNA studies include using a sampling volume and design to maximise the number of taxa detected and optimising the sequencing depth. However, increasing the coverage of reference sequence databases would yield the most significant improvements in the accuracy of taxonomic assignments made using the P6 loop of the trnL region.

Neotropical Clavulina: Two new species from Mexico and a re-evaluation of Clavulina floridana.

Clavulina comprises ca. 90 described species distributed worldwide in both tropical and temperate regions. However, only one species (C. floridana) has been described so far from tropical North America. We used morphological and molecular data from three DNA loci (nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 [ITS], a portion of nuc 28S rDNA [28S], and a fragment of DNA-directed RNA polymerase II second largest subunit [RPB2]) from basidiomata and ectomycorrhizas collected in tropical ecosystems from three biogeographic provinces of Mexico and one tropical province in the USA to investigate the phylogenetic and taxonomic diversity of Clavulina in the region. Nine new species-level clades were discovered, two of which are proposed as new species (C. arboreiparva and C. tuxtlasana). Specimens of C. floridana recently collected in Florida were included in our analyses, for which a modern description is provided. In addition, C. floridana is a new record for Mexico. The diversity of Clavulina in tropical North America is comparable to that found in lowland tropical South America. However, some of the species found in tropical deciduous forests produce small, rare, and inconspicuous basidiomata, which easily go unnoticed, and therefore are poorly represented in collections. Many species remain undescribed in tropical regions of North America.

Agaricus macrochlamys, a New Species from the (Sub)tropical Cloud Forests of North America and the Caribbean, and Agaricus fiardii, a New Synonym of Agaricus subrufescens.

Agaricus is a genus of fungi in the family Agaricaceae, with several highly priced edible and medicinal species. Here we describe Agaricus macrochlamys, a new species, in A. sect. Arvenses, sympatric and morphologically cryptic with the edible and medicinally cultivated mushroom, A. subrufescens. Phylogenetic analyses showed that A. macrochlamys is closely related to A. subrufescens, and that A. fiardii is a new synonym of A. subrufescens. Despite being morphologically cryptic, A. macrochlamys can be distinguished from A. subrufescens by several ITS and tef1α species-specific markers and a 4-bp insertion in the tef1α sequence. Furthermore, A. subrufescens is a cosmopolitan species, while A. macrochlamys distribution is so far restricted to Mexico, the Dominican Republic, and the United States.

Cordyceps mexicana sp. nov., parasitizing Paradirphia sp. moths: A new sister species of the Cordyceps militaris complex, distributed in central Mexican Quercus-Pinus mixed forests.

Cordyceps s.l. is a paraphyletic group of ascomycete fungi that exhibit multifunctional lifestyles, that is, as saprotrophs, endophytes, and pathogens of insects, spiders, fungi, and grasses. The family Cordycipitaceae includes macroscopically similar species that have been erroneously considered to be conspecific with Cordyceps militaris. In this study, we describe a new species within the C. militaris complex that is distributed in the Quercus-Pinus forests of central Mexico on the basis of its morphology, phylogenetic relationships, and life cycle. Phylogenetically, Cordyceps mexicana is a well-supported new sister species of the C. militaris complex. It is distinguished by the morphology of its conidiophore, host association, and geographic distribution. This species parasitizes pupae of Paradirphia sp. (Lepidoptera: Saturniidae: Hemileucinae) and might be macroscopically confused with C. militaris. Its stromata are large, can measure up to 10 cm in length, and the fertile part is always bright yellow. This species develops whitish mycelial cords that emerge from the stromata and grow toward the host. Microscopically, it develops asci with filiform ascospores disarticulating in part-spores. Its life cycle and geographic distribution are also discussed.

Hemiaustroboletus, a new genus in the subfamily Austroboletoideae (Boletaceae, Boletales).

The present study describes Hemiaustroboletus gen. nov. in the subfamily Austroboletoideae (Boletaceae). Hemiaustroboletus is supported by morphological and molecular data using LSU and RPB2 regions. Additionally, its geographic distribution and intraspecific variation were inferred using ITS sequences. The genus is characterised by pileate-stipitate basidiomata; purple, brown, reddish-brown, orange-brown to dark brown vinaceous pileus; whitish or lilac to vinaceous context and a subclavate stipe. Microscopically, it is characterised by ornamented, slightly verrucose, cracked to perforated brown basidiospores. Two species are described within the genus, Hemiaustroboletusvinaceobrunneus sp. nov. and H.vinaceus sp. nov. Hemiaustroboletusvinaceus sp. nov. is morphologically similar to Austroboletusgracilis, which suggests they may have been confused in the past. This study presents the phylogenetic placement, microscopic structures, detailed morphological descriptions and illustrations of both new species.

Quercetin and 1-methyl-2-oxindole mimic root signaling that promotes spore germination and mycelial growth of Gigaspora margarita.

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs, and the difficulty of growing them in asymbiotic or monoxenic (AMF + root) conditions limits research and their large-scale production as biofertilizer. We hypothesized that a combination of flavanols and strigolactones can mimic complex root signaling during the presymbiotic stages of AMF. We evaluated the germination, mycelial growth, branching, and auxiliary cell clusters formation by Gigaspora margarita during the presymbiotic stage in the presence (or absence) of transformed Cichorium intybus roots in basal culture medium enriched with glucose, a flavonol (quercetin or biochanin A) and a strigolactone analogue (1-Methyl-2-oxindole or indole propionic acid). With quercetin (5 µM), methyl oxindole (2.5 nM), and glucose (8.2 g/L) in the absence of roots, the presymbiotic mycelium of G. margarita grew without cytoplasmic retraction and produced auxiliary cells over 71 days similar to presymbiotic mycelium in the presence of roots but without glucose, strigolactones, and flavonols. Our results indicate that glucose and a specific combination of certain concentrations of a flavonol and a strigolactone might be used in asymbiotic or monoxenic liquid or semisolid cultures to stimulate AMF inoculant bioprocesses.

Truffle Microbiome Is Driven by Fruit Body Compartmentalization Rather than Soils Conditioned by Different Host Trees.

Truffles are among the most expensive edible mushrooms; their value is worth billions of U.S. dollars annually in international markets. They establish ectomycorrhizal symbiotic relationships with diverse host tree roots and produce hypogeous ascomata. Their whole life cycle is closely related to their associated microbiome. However, whether truffle-associated compartments or host tree rhizospheres are the vital driver for truffle ascomata microbiome is unclear. To identify and compare fungal and bacterial communities in four truffle-associated compartments (Tuber indicum: bulk soil, adhering soil to peridium, peridium, and gleba) from three host trees, we sequenced their ITS (fungal) and 16S (bacterial) ribosomal DNA using the Illumina MiSeq high-throughput platform. We further applied the amplicon data to analyze the core microbiome and microbial ecological networks. Tuber indicum microbiome composition was strongly driven by its associated compartments rather than by their symbiotic host trees. Truffle microbiome was bacteria dominated, and its bacterial community formed a substantially more complex interacting network compared to that of the fungal community. The core fungal community changed from Basidiomycota dominated (bulk soil) to Rozellomycota dominated (interphase soil); the core bacterial community shifted from Bacteroidetes to Proteobacteria dominance from truffle peridium to gleba tissue. Especially, at the truffle and soil interphase, the niche-based selection of truffle microbiome was verified by (i) a clear exclusion of four bacterial phyla (Rokubacteria, Nitrospirae, Chloroflexi, and Planctomycetes) in gleba; (ii) a significant decrease in alpha-diversity (as revealed by Chao 1, Shannon, and Simpson indices); and (iii) the complexity of the network substantially decreased from bulk soil to soil-truffle interphase and further to the peridium and gleba. The network analysis of microbiome showed that the microbial positive interactions were higher in truffle tissues than in both bulk soil and peridium-adhering soil and that Cupriavidus, Bradyrhizobium, Aminobacter, and Mesorhizobium spp. were the keystone network hubs in the truffle gleba. This study provides insights into the factors that drive the truffle microbiome dynamics and the recruitment and function of the microbiome components. IMPORTANCE Currently, the factors that drive the microbiome associated with truffles, the most highly prized fungi in the world, are largely unknown. We demonstrate for the first time here that truffle microbiome composition is strongly driven by associated compartments rather than by symbiotic host trees. The truffle microbiome was bacteria dominated, and its bacterial community formed a substantially more complex (with the higher numbers of nodes, links, and modules) interacting network compared to that of the fungal community. Network analysis showed a higher number of positive microbial interactions with each other in truffle tissues than in both bulk soil and peridium-adhering soil. For the first time, the fungal community structure associated with truffles using high-throughput sequencing, microbial networks, and keystone species analyses is presented. This study provides novel insights into the factors that drive the truffle microbiome dynamics and the recruitment and function of the microbiome components, showing that they are more complex than previously thought.

Breaking the paradigms of residual categories and neglectable importance of non-used resources: the "vital" traditional knowledge of non-edible mushrooms and their substantive cultural significance.

INTRODUCTION: One of the main goals of ethnomycological studies has been understanding the role of wild edible mushrooms (WEM) in diverse cultures. To accomplish such a purpose, the local knowledge of WEM and their cultural importance have been evaluated and compared using qualitative and quantitative methods. However, few studies have documented these aspects in non-edible mushrooms, because they are considered to be in a category of residual cultural importance. To make up for this lack of investigation, this paper analyzes the traditional knowledge of non-edible mushrooms to understand their cultural role and break it down to its components. The analysis of this topic shows how this knowledge represents a good strategy to prevent mushroom intoxications in humans. METHODS: This study was carried out in two communities residing in La Malintzi National Park, Tlaxcala, Mexico. Mushroom species indicated as non-edible were collected during 13 ethnomycological expeditions and seven requests. To get an insight into the local knowledge about these mushrooms, we used ethnographic techniques, 91 free listings and 81 semi-structured interviews. RESULTS: In total, we collected 178 specimens of wild mushrooms recognized as non-edible by locals, which corresponded to 103 species belonging to 45 genera. People who participated in the study had a vast and deep understanding of non-edible mushrooms. For them, the most important species were Amanita muscaria, Neoboletus aff. erythropus, Xerocomellus chrysenteron, and Suillus tomentosus. Two uses were the most mentioned by respondents: as an insecticide and for medicinal purposes. Of note, however, is that A. muscaria was reported as edible years ago. To avoid possible intoxication, all non-edible mushrooms were included in the general category of "poisonous mushrooms." Non-edible species are seen as a cosmogonic counterpart ("twins") of the edible species that they resemble. We obtained 101 specific recognition criteria, useful only when comparing paired species: edible vs non-edible. The most culturally important non-edible groups were differentiated by clear and precise characteristics, which were reflected in the nomenclature and allowed their classification into specific ethnotaxa. CONCLUSIONS: We found that non-used resources can be the object of a deep traditional knowledge and have a vast cultural importance. In the case of wild non-edible mushrooms in particular: the species are named; they are the subject of vast traditional knowledge which is based on their edible/non-edible duality; this knowledge is widespread but has limited consensus, there is little lexical retention; and this knowledge is vital to avoid fatal intoxications. In consequence, both deadly species and species that share similarities with the most important edible mushrooms have a high cultural importance.

From field sampling to pneumatic bioreactor mycelia production of the ectomycorrhizal mushroom Laccaria trichodermophora.

In order to increase survival rates of greenhouse seedlings destined for restoration and conservation programs, successful mycorrhization of the seedlings is necessary. To reforest forest ecosystems, host trees must be inoculated with ectomycorrhizal fungi and, in order to guarantee a sufficient supply of ectomycorrhizal inoculum, it is necessary to develop technologies for the mass production of ectomycorrhizal fungi mycelia. We selected the ectomycorrhizal fungus Laccaria trichodermophora, due to its ecological traits and feasible mycelia production in asymbiotic conditions. Here, we report the field sampling of genetic resources, as well as the highly productive nutritional media and cultivation parameters in solid cultures. Furthermore, in order to achieve high mycelial production, we used strain screening and evaluated pH, carbon source concentration, and culture conditions of submerged cultures in normal and baffled shake flasks. The higher productivity culture conditions in shake flasks were selected for evaluation in a pneumatic bioreactor, using modified BAF media with a 10 g/L glucose, pH 5.5, 25 °C, and a volumetric oxygen transfer coefficient (KLa) of 36 h-1. Under those conditions less biomass (12-37 %) was produced in the pneumatic bioreactor compared with the baffled shake flasks. This approach shows that L. trichodermophora can generate a large biomass concentration and constitute the biotechnological foundation of its mycelia mass production.

Description and distribution of Tuberincognitum sp. nov. and Tuberanniae in the Transmexican Volcanic Belt.

The genus Tuber is a lineage of diverse ectomycorrhizal, hypogeous, sequestrate ascomycete fungi that are native to temperate forests in the Northern Hemisphere. Recently, many new species of Tuber have been described in North America and Asia, based on morphological characteristics and molecular data. Here we describe and illustrate a new species, Tuberincognitum, based upon phylogenetic analysis and morphological description. We also present a new record for Tuberanniae in México. These two Tuber species are distributed in the Transmexican Volcanic Belt in the states of México, Michoacán, Guanajuato, Querétaro and Tlaxcala at altitudes between 2,000 and 3,200 meters. These species are associated with Pinus (T.anniae) and Quercus forests (T.incognitum).

Identifying and naming the currently known diversity of the genus Hydnum, with an emphasis on European and North American taxa.

In this study, 49 species of Hydnum are recognized worldwide. Twenty-two of them are described here as new species. Epitypes are proposed for H. repandum and H. rufescens. The majority of the species are currently known only from a single continent. The barcodes produced in this study are deposited in the RefSeq database and used as a basis to name species hypotheses in UNITE. Eleven infrageneric clades recovered in a phylogenetic analysis are supported by morphological characteristics and formally recognized: subgenera Alba, Hydnum, Pallida, and Rufescentia; sections Hydnum, Olympica, Magnorufescentia, and Rufescentia; and subsections Mulsicoloria, Rufescentia, and Tenuiformia.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico

Abstract The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

Ectomycorrhizal fungal communities in high mountain conifer forests in central Mexico and their potential use in the assisted migration of Abies religiosa.

Abies religiosa forests in central Mexico are the only overwinter refuge of the monarch butterfly and provide important ecosystem services. These forests have lost 55% of their original area and as a consequence, diversity and biotic interactions in these ecosystems are in risk. The aim of this study was to compare the soil fungal diversity and community structure in the Abies religiosa forests and surrounding Pinus montezumae, Pinus hartwegii, and coniferous mixed forest plant communities to provide data on ecology of mycorrhizal interactions for the assisted migration of A. religiosa. We sampled soil from five coniferous forests, extracted total soil DNA, and sequenced the ITS2 region by Illumina MiSeq. The soil fungi community was integrated by 1746 taxa with a species turnover ranging from 0.280 to 0.461 between sampling sites. In the whole community, the more abundant and frequent species were Russula sp. (aff. olivobrunnea), Mortierella sp.1, and Piloderma sp. (aff. olivacearum). The ectomycorrhizal fungi were the more frequent and abundant functional group. A total of 298 species (84 ectomycorrhizal) was shared in the five conifer forests; these widely distributed species were dominated by Russulaceae and Clavulinaceae. The fungal community composition was significantly influenced by altitude and the lowest species turnover happened between the two A. religiosa forests even though they have different soil types. As Pinus montezumae forests have a higher altitudinal distribution adjacent to A. religiosa and share the largest number of ectomycorrhizal fungi with it, we suggest these forests as a potential habitat for new A. religiosa populations.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico.

The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

Caryophyllales are the main hosts of a unique set of ectomycorrhizal fungi in a Neotropical dry forest.

The ectomycorrhizal symbiosis was long thought to be restricted to temperate forests. However, as tropical forests have been explored, it has become clear that these habitats host unique ectomycorrhizal (ECM) fungi. We have been exploring tropical dry forests (TDF), which are endangered terrestrial ecosystems and hotspots of endemism. Since Fabaceae is the main plant family in this environment, we hypothesized that trees in this lineage would be the main ECM hosts. We sequenced the ITS rDNA region from fungi and both rbcL and trnL cpDNA from plants to identify both symbiotic partners from root tips. The systematic position of each symbiont was confirmed by Bayesian phylogenetic inference. We identified 20 plant species belonging to 10 families that hosted 19 unique ECM fungal species from 5 lineages. Most ECM fungi were associated with Caryophyllales, not with Fabaceae. Achatocarpus and Guapira, the main hosts, are scattered throughout the forest and are not in monodominant patches. The low ECM fungal diversity can be explained by the low density of host plants and their high specificity. Our results indicate that Caryophyllales is an important order of tropical ECM hosts with at least four independent evolutionary lineages that have evolved the ability to form ectomycorrhizae.

Word-wide meta-analysis of Quercus forests ectomycorrhizal fungal diversity reveals southwestern Mexico as a hotspot.

Quercus is the most diverse genus of ectomycorrhizal (ECM) host plants; it is distributed in the Northern and Southern Hemispheres, from temperate to tropical regions. However, their ECM communities have been scarcely studied in comparison to those of conifers. The objectives of this study were to determine the richness of ECM fungi associated with oak forests in the Cuitzeo basin in southwestern Mexico; and to determine the level of richness, potential endemism and species similarity among ECM fungal communities associated with natural oak forests worldwide through a meta-analysis. The ITS DNA sequences of ECM root tips from 14 studies were included in the meta-analysis. In total, 1065 species of ECM fungi have been documented worldwide; however, 812 species have been only found at one site. Oak forests in Europe contain 416 species, Mexico 307, USA 285, and China 151. Species with wider distributions are Sebacinaceae sp. SH197130, Amanita subjunquillea, Cenococcum geophilum, Cortinarius decipiens, Russula hortensis, R. risigallina, R. subrubescens, Sebacinaceae sp. SH214607, Tomentella ferruginea, and T. lapida. The meta-analysis revealed (1) that Mexico is not only a hotspot for oak species but also for their ECM mycobionts. (2) There is a particularly high diversity of ECM Pezizales in oak seasonal forests from western USA to southwestern Mexico. (3) The oak forests in southwestern Mexico have the largest number of potential endemic species. (4) Globally, there is a high turnover of ECM fungal species associated with oaks, which indicates high levels of alpha and beta diversity in these communities.