Abstract Inocybe is a globally distributed genus of ectomycorrhizal fungi that occurs in temperate and tropical regions. However, species diversity of the genus in Africa remains underexplored. In this study, four new nodulose-spored Inocybe species, I . arenosa , I . basialba , I . liliputiana , and I . luteofusca , from tropical regions of Benin in West Africa, are described and illustrated based on comprehensive morphological and molecular analyses. In addition, I . glaucodisca, originally described from Zambia (Southeast Africa), is reported for the first time from West Africa (Benin). All five Inocybe species occur in association with Berlinia grandiflora ( Fabaceae ). Multilocus molecular analyses of the nuclear ribosomal internal transcribed spacer region (nrITS), a partial of the nuclear ribosomal large subunit (nrLSU), and a segment of the RNA polymerase II second-largest subunit ( RPB2 ) gene, confirm the distinctiveness of these four novel species and indicate their phylogenetic placement within Inocybe .

Abstract Seiridium is a genus of Sordariomycetes ( Amphisphaeriales , Sporocadaceae ), primarily known for species that cause cypress canker on Cupressaceae trees. However, most species in this genus have been reported from angiosperms, including many species in the native range of their hosts. Several unidentified Seiridium strains, collected > 20 years ago from Acacia mearnsii trees in eastern South Africa and southeastern Australia, were recently recovered from a collection of preserved cultures. We considered the phylogenetic position of these Seiridium strains and assessed their pathogenicity on A. mearnsii . Maximum likelihood analysis of three concatenated gene regions revealed four well-supported clades. Two closely related clades corresponded to Australian and South African origins, whereas two other clades representing South African isolates formed a monophyletic group with S. kartense , a species known from Eucalyptus cladocalyx on Kangaroo Island in Australia. Genome-wide average pairwise nucleotide identity and genetic differentiation analysis supported three species, including isolates considered conspecific with S. kartense and two that we consider to represent new species. These are described and named here as Seiridium mearnsii sp. nov. and Seiridium rouxiae sp. nov. Inoculations with South African isolates failed to produce evidence of pathogenicity. Seiridium species from A. mearnsii have likely been introduced into South Africa from Australia, along with the planting material used to establish A. mearnsii forestry.

Abstract The fungi causing diseases of cereal crops and other grasses, known as the brown leaf rusts, have historically been classified in the Puccinia recondita (sensu lato) species complex. Despite a long history of taxonomic effort, the recognition of the many included discrete taxa has been challenged due to overlapping morphological characters and primary grass hosts. More recent studies employing DNA sequence analyses identified multiple phylogenetic lineages in the complex, with two corresponding to species important to agricultural production, Puccinia triticina and P. recondita sensu stricto, on wheat and rye respectively. In this study, a second wheat-associated species, Puccinia tritici-duri , as yet known only from the Mediterranean region, and a new species recently discovered in the Golan Heights on wild emmer wheat, were examined and compared with P. triticina . We conducted detailed morphological examinations of telial and uredinial stages, DNA sequence analyses of the ribosomal DNA internal transcribed spacer region and elongation factor 1-α, and greenhouse inoculation experiments using a broad selection of Triticum and Aegilops telial hosts. The results demonstrated that the three wheat-associated species are distinct, placed in three unrelated lineages within the P. recondita complex. They confirm an overlap in host associations, which varied depending on species or cultivar. Based on the combined evidence, we formally propose the new species as Puccinia tritici-golanensis and provide comprehensive notes for the other two species, supported by descriptions and illustrations.

Abstract Phytophthora species pose a significant threat to citrus production in the Mediterranean, particularly in Sicily, a major citrus-producing region. This study explores the diversity and distribution of Phytophthora taxa in Sicilian citrus orchards, addressing the urgent need to tackle increasing agricultural challenges, such as climate change. Specifically, it aimed to evaluate how environmental factors, such as the type of management (organic vs. conventional) and geographical area influence the composition of Phytophthora communities in Sicilian citrus orchards, and whether these communities correlate with tree health. An additional objective was to compare the effectiveness of traditional baiting and high-throughput metabarcoding techniques (targeting the ITS1 region and RPS10 gene) in capturing this diversity, as well as to assess potential shifts in community structure resulting from climate change by comparing current data with historical records. Soil samples were collected from ten citrus-producing areas under two distinct agronomic management and tree health conditions. Traditional baiting recovered 556 isolates of three already described Phytophthora species, while ITS1 metabarcoding identified ten additional taxa, demonstrating higher specificity (99.5% of ITS1 reads classified as Phytophthora compared to 82.5% for RPS10 ). Our findings indicate that geographical location is a key driver of community composition. Although statistical analyses did not reveal significant differences in Phytophthora diversity between organic and conventional management systems, these results provide valuable insights into the factors shaping pathogen communities. These insights are crucial for developing targeted disease management strategies and for understanding how environmental stressors, including climate change, impact pathogen dynamics in Mediterranean citrus orchards. Graphical Abstract

Abstract Species determination in the Amidella clade is notoriously difficult, because of the relative dearth of diagnostic characters and the rather common occurrence of homoplasies. This results in a substantial number of misnamed and unnamed collections, a misapprehension of the geographic range of known species and a gross underestimation of the number of species it contains. To assess the diversity that should be considered as part of Amidella , DNA sequences available for this group were retrieved in public nucleotide databases, using a combination of approaches to achieve a comprehensive representation. Phylogenetic analysis based on the aligned ITS sequences, consistently with the results from other molecular markers (ncLSU, RPB2 , TEF1 , BTUB ), suggests five major clades: one containing the type species Amanita volvata ; another for Amanita ponderosa and allies; a third one (roughly half of all species) with Amanita lepiotoides ; and two others without valid species yet. At species level, around 81 clades were delimited, of which only 16–17 can be assigned a valid name, with a few more corresponding to provisional taxa listed in the amanitaceae.org website. Up to three further species without assigned sequences might correspond to the proposed clades. The current evidence suggests a rather narrow geographic range for most of these clades. This study provides a phylogeny-arranged outlook of the worldwide distribution of Amidella species and an infrasectional framework for optimising taxonomic sampling and designing clade-specific molecular markers to assist in identification. Graphical Abstract