Isolation and Enzymatic Characterization of Fungal Strains from Grapevines with Grapevine Trunk Diseases Symptoms in Central Mexico.

Grapevine production is economically indispensable for the global wine industry. Currently, Mexico cultivates grapevines across approximately 28 500 hectares, ranking as the 26th largest producer worldwide. Given its significance, early detection of plant diseases' causal agents is crucial for preventing outbreaks. Consequently, our study aimed to identify fungal strains in grapevines exhibiting trunk disease symptoms and assess their enzymatic capabilities as indicators of their phytopathogenic potential. We collected plant cultivars, including Malbec, Shiraz, and Tempranillo, from Querétaro, Mexico. In the laboratory, we superficially removed the plant bark to prevent external contamination. Subsequently, the sample was superficially disinfected, and sawdust was generated from the symptomatic tissue. Cultivable fungal strains were isolated using aseptic techniques from the recovered sawdust. Colonies were grown on PDA and identified through a combination of microscopy and DNA-sequencing of the ITS and LSU nrDNA regions, coupled with a BLASTn search in the GenBank database. We evaluated the strains' qualitative ability to degrade cellulose, starch, and lignin using specific media and stains. Using culture morphology and DNA-sequencing, 13 species in seven genera were determined: Acremonium, Aspergillus, Cladosporium, Dydimella, Fusarium, Sarocladium, and Quambalaria. Some isolated strains were able to degrade cellulose or lignin, or starch. These results constitute the first report of these species community in the Americas. Using culture-dependent and DNA-sequencing tools allows the detection of fungal strains to continue monitoring for early prevention of the GTD.

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.

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.

Clavulina-Membranomyces is the most important lineage within the highly diverse ectomycorrhizal fungal community of Abies religiosa.

Abies religiosa is an endemic conifer of Mexico, where its monodominant forests are the winter refuge of the monarch butterfly. Due to climate change, it has been estimated that by 2090, A. religiosa populations will decline by 96.5 %. To achieve success, reforestation programs should consider its ectomycorrhizal (ECM) fungi. We used ITS nrDNA sequences to identify the ECM fungi associated with A. religiosa and, based on its abundance and frequency, determined the diversity and community structure in a pure A. religiosa forest near Mexico City. Using sequence metadata, we inferred the species geographic distribution and host preferences. We conducted phylogenetic analyses of the Clavulinaceae (the most important family). The ECM community held 83 species, among which the richest genera were Inocybe (21 species), Tomentella (10 species), and Russula (8 species). Besides its low species richness, the Clavulina-Membranomyces lineage was the most dominant family. Clavulina cf. cinerea and Membranomyces sp. exhibited the highest relative abundance and relative frequency values. Phylogenetic analyses placed the Clavulinaceae genotypes in three different clades: one within Membranomyces and two within Clavulina. A meta-analysis showed that the majority of the ECM fungi (45.78 %) associated with A. religiosa in Mexico have also been sequenced from North America and are shared by Pinaceae and Fagaceae. In contrast, because they have not been sequenced previously, 32.2 % of the species have a restricted distribution. Here, we highlight the emerging pattern that the Clavulina-Membranomyces lineage is dominant in several ECM communities in the Neotropics, including Aldinia and Dicymbe legume tropical forests in the Guyana Shield, the Alnus acuminata subtropical communities, and the A. religiosa temperate forests in Mexico.