Species concepts in Cercospora: spotting the weeds among the roses

Identifying Root-Associated Endophytic Fungi and Bacteria in Festuca and Lolium Grasses from a Site in Lithuania

This study investigates the diversity and distribution of root endophyte fungi and bacteria across Festuca and Lolium grasses, including open-grassland and forest species. The species examined include perennials such as Festuca arundinacea, F. gigantea, F. pratensis, Lolium perenne, and L. perenne × F. gigantea hybrids and the annuals L. temulentum and L. multiflorum. A total of 21 fungal species (60 isolates) and 26 bacterial taxa (59 isolates) were recovered in the culture (PDA medium for fungi and LB for bacteria) from the root cuttings of these grasses. Microdochium bolleyi fungi and Bacillus sp. bacteria were the most prevalent endophytes, with each being identified in five of the seven plant species examined. The annuals L. multiflorum and L. temulentum exhibited a higher abundance of endophytes than that in their perennial relatives, suggesting the benefits of microbial associations in supporting their short life cycles. The woodland F. gigantea demonstrated the highest fungal endophyte diversity, with six species identified. In contrast, the open-grassland perennials F. arundinacea, F. pratensis, and L. perenne hosted only one to two species. Two Basidiomycota, Coprinellus disseminatus and Sistotrema brinkmannii, were exclusively obtained from the roots of the forest grass F. gigantea. Notably, the open-grassland perennial F. arundinacea exhibited the highest bacterial diversity, with nine species present. However, it showed the lowest fungal diversity, with only one species detected. Overall, our study reveals distinct patterns of fungal and bacterial endophyte diversity in the roots of Festuca and Lolium grasses, with variations linked to host species, growth type traits, and ecological adaptations. Among the root-derived endophytes isolated, several fungi and bacteria are potential candidates for plant growth promotion and biocontrol. Therefore, the findings of this study provide potential implications for improved grassland management and crop breeding strategies aimed at specific climate and/or soil conditions.

Intra-Leaf Variability of Incubation Period Sheds New Light on the Lifestyle of Cercospora beticola in Sugar Beets

The length of incubation period, i.e., the time between first contact of host and pathogen and the appearance of symptoms, varies among diseases and depends on environmental conditions. Cercospora beticola is the most important fungal pathogen in sugar beet production worldwide, as Cercospora leaf spot (CLS) reduces the leaf area contributing to yield formation. Using sugar beet cultivars differing in CLS resistance, a single infection period of C. beticola resulted in minor differences in the incubation period among host genotypes and among individual plants of cultivars, greater differences among leaves within plants, and substantial variation within individual leaves. Under greenhouse conditions not suitable for secondary infections, the first CLS lesions appeared 10 days after inoculation; however, the number of leaf spots and CLS severity further increased significantly for another 7 to 17 days. A geographic information system approach enabled the tracking of colony appearance and growth of all CLSs on inoculated leaves for up to 27 days. Asymptomatic colonization of leaves was associated with thick hyphae which switched to thin hyphae or melanization after lesion appearance. The lifestyle of C. beticola-intercellular tissue colonization, triggering of necrotic host reaction-is discussed considering the experimental results as well as literature resources.

Unveiling four new taxa and Nigrosynnemanatarajanensis comb. nov. in Stachybotryaceae (Hypocreales) from monocotyledon plants in Guangdong Province, China

Members of Stachybotryaceae are distributed worldwide, with certain species playing a significant role as bio-degraders and some causing diseases in plants, humans, and animals. Other species within this family can be found in soil and have been reported as saprobes in various plants. In this study (2021-2022), fungal taxa resembling Stachybotryaceae, isolated from dead leaves of Agavesisalana and a dead stem of Wurfbainiavillosa in Guangdong Province, China, are identified based on morphological characteristics and molecular data. Multi-locus phylogeny based on calmodulin (cmdA), internal transcribed spacer (ITS), the large subunit nuclear rDNA (LSU), RNA polymerase II second largest subunit (rpb2), the partial translation elongation factor 1-α (tef1-α), and β-tubulin (tub2) revealed that nine strains were grouped within Stachybotryaceae. Nigrosynnemaguangdongense gen. et sp. nov., typical of Stachybotryaceae but having unusual olivaceous brown to black synnemata that are narrower towards the apex and produce phialidic, aseptate, slimy conidia in black and glistening heads, is introduced. Additionally, Brevistachyswurfbainiae and Sirastachysguangdongensis are introduced as new species. Stachybotrysmicrosporus is a new host record for Agavesisalana. The present study provides comprehensive descriptions, illustrations, and molecular data analyses of the newly discovered taxa and newly recorded species as a taxonomic and phylogenetic contribution to Stachybotryaceae. Furthermore, a new combination, Nigrosynnemanatarajanensis, is proposed for the previously described Virgatosporanatarajanensis.

Bulbillosins A - E, azaphilones from Tengochaetabulbillosa sp. nov. (Chaetomiaceae), a root endophyte of the Chinese medicinal plant Astertataricus

Astertataricus is a plant used in Traditional Chinese Medicine. From its roots, we isolated four endophytic fungi strains. After mass spectrometry analysis and subsequent molecular networking and dereplication, one of the strain's extracts showed a cluster of yet undescribed natural products. Additionally, the extract was found to be lethal for the nematode Caenorhabditiselegans and cytotoxic against eukaryotic cell lines. The fungal strain was characterized by morphological and molecular studies, allowing its description as a new species in the genus Tengochaeta (Chaetomiaceae), Tengochaetabulbillosa. After cultivation and extraction of the strain, the major secondary metabolites were isolated. Structure elucidation based on nuclear magnetic resonance spectroscopy and high-resolution tandem mass spectrometry revealed these compounds to be five new azaphilones. Additionally, the localization of these azaphilones in the host plant was studied by mass spectrometry imaging of different plant tissues, revealing that they were mainly localized in the aerial parts of the plant. The main compound, bulbillosin A, was evaluated for its activity against sixty cancer cell lines, revealing a differential cytotoxicity profile.

Trichoderma collection from Brazilian soil reveals a new species: T. cerradensis Sp. nov

Trichoderma spp. are important biological control agents and plant growth promoters. However, only a limited number of species are used in biological control even though the genus contains more than 400 species, with most of them being mycotrophic. In this study, 97 Trichoderma isolates preserved at the EMBRAPA collection (an important source for biocontrol agents) and previously collected from several areas in Brazil were characterized which were identified using various molecular markers (internal transcribed spacers (its), translation elongation factor (tef1α), RNA polymerase II subunit (rpb2), actin (act), and calmodulin (cal). Of these, 54 isolates were found to group in the Harzianum species complex and 32 in Sect. Trichoderma. Others were distributed in the following clades: Strictipilosa complex (one isolate), Longibrachiatum (four isolates), and Brevicompactum (seven isolates). Most of the isolates were identified within 17 known species, whereas Trichoderma inhamatum and T. dorothopsis were synonymized under T. lentiforme and T. koningiopsis, respectively, based on multi-locus phylogenetic analysis and GCPRS criteria. However, two isolates formed a clade apart from previously identified species from Sect. Trichoderma and identified as a new species: T. cerradensis sp. nov. The multigenic characterization of isolates deposited in fungal culture collections is crucial for accurate identification and reveals a diverse range of Trichoderma species in Brazil.

Molecular Tracking of Emerging Fusarium Species in Keratitis: F. veterinarium, F. contaminatum, and F. curvatum

Fungal keratitis, which is caused primarily by Neocosmospora and Fusarium species, is a significant global health issue that affects more than a million people annually in tropical and subtropical regions. Neocosmospora solani (formerly Fusarium solani) is a leading cause of corneal infections, along with members of the Fusarium oxysporum species complex (FOSC). This study provides new insights by reporting a series of ocular fusariosis cases caused by FOSC members and presenting molecular evidence linking specific haplotypes within FOSC to human infections. We describe three cases of Fusarium keratitis selected from a comprehensive review of clinicopathological data in our institution's archives. These cases were chosen for their distinctive clinical presentations and the involvement of less common Fusarium species. Two of these patients were diagnosed with keratitis and anterior endophthalmitis, and the third patient had a corneal ulcer previously treated with topical antivirals and antibiotics. All patients were successfully treated with topical amphotericin B. The Fusarium isolates from these patients were subjected to detailed molecular characterization, including DNA sequencing (tef1α, rpb2, CaM, tub2, and LSU), amplified fragment length polymorphism (AFLP) marker analysis, and MALDI-TOF MS analysis. Remarkably, our study reports the first case of human infection by F. veterinarium, alongside cases involving F. contaminatum and F. curvatum. Furthermore, a molecular survey using haplotypic networks based on tef1α sequences identified genotypes associated with human infections and revealed the emergence of F. veterinarium clade VII. Our findings emphasize the need for vigilance regarding emerging species within the FOSC, particularly F. veterinarium. This highlights the need for improved diagnostic tools and targeted research to combat fusarioid-related infections effectively.

Identification of Cercospora spp. on Corn in North America and Baseline Flutriafol Fungicide Sensitivity

Gray leaf spot (GLS) is an important corn disease reportedly caused by Cercospora zeae-maydis and C. zeina. Recently, flutriafol, a demethylation inhibitor (azole) fungicide, received Environmental Protection Agency registration as Xyway LFR, a product that is applied at planting for management of fungal diseases in corn, including suppression of GLS. In this study, 448 Cercospora spp. isolates were collected in 2020 and 2021 from symptomatic corn leaf samples submitted from the United States and Ontario, Canada. The Cercospora spp. were identified using multilocus genotyping of the internal transcribed spacer, elongation factor 1-α, calmodulin, histone H3, and actin genes. Based on the multilocus phylogenetic analyses, six species were identified; C. cf. flagellaris (n = 77), C. kikuchii (n = 4), C. zeae-maydis (n = 361), Cercospora sp. M (n = 2), Cercospora sp. Q (n = 1), and Cercospora sp. T (n = 3). In subsequent pathogenicity tests using selected isolates from each of these species, only C. zeae-maydis resulted in symptoms on corn, with no disease symptoms observed after inoculation with C. cf. flagellaris, C. kikuchii, Cercospora sp. M, Cercospora sp. Q, and Cercospora sp. T. Disease symptoms were observed on soybean following inoculation with C. cf. flagellaris, C. kikuchii, and Cercospora sp. Q, but not the other three species. Fungicide sensitivity of Cercospora spp. to flutriafol was assessed using a subset of 340 isolates. The minimum inhibitory concentration (MIC) to inhibit the growth of Cercospora spp. completely was determined based on growth of each species on flutriafol-amended clarified V8 agar at nine concentrations. The effective concentration of fungicide required for 50% growth inhibition (EC50) was also calculated from the same trial by measuring relative growth as compared with the nonamended control. Cercospora zeae-maydis was sensitive to flutriafol, with mean MIC values of 2.5 μg/ml and EC50 values ranging from 0.016 to 1.020 μg/ml with a mean of 0.346 μg/ml. Cercospora cf. flagellaris, C. kikuchii, Cercospora sp. M, Cercospora sp. Q, and Cercospora sp. T had mean EC50 values of 1.25, 7.14, 2.48, 1.81, and 2.24 μg/ml, respectively. These findings will assist in monitoring the sensitivity to the flutriafol fungicide in Cercospora spp. populations.

Recticladiella inexpectata gen. et sp. nov. (Nectriaceae) Pathogenic to Native Cinnamomum camphora (Lauraceae) Trees in Southeastern China

The ascomycete family Nectriaceae includes soil-borne saprobes, plant pathogens and human pathogens, biodegraders, and biocontrol agents for industrial and commercial applications. Cinnamomum camphora is a native tree species that is widely planted in southern China for landscaping purposes. During a routine survey of Eucalyptus diseases in southern China, disease spots were frequently observed on the leaves of Ci. camphora trees planted close to Eucalyptus. The asexual fungal structures on the leaf spots presented morphological characteristics typical of the Nectriaceae. The aim of this study is to identify these fungi and determine their pathogenic effect on Ci. camphora. Of the isolates obtained from 13 sites in the Fujian and Guangdong Provinces, 54 isolates were identified based on the DNA phylogeny of the tef1, tub2, cmdA, and his3 regions and morphological features. Two isolates were identified as Calonectria crousiana, and fifty-two isolates were described as a new genus, including a single species. These fungi were named Recticladiella inexpectata gen. et sp. nov. The identification of the new genus was based on strong DNA base differences in each of the four sequenced gene regions. The conidiophores of this fungus had several avesiculate stipe extensions tapering toward a straight, occasionally slightly curved terminal cell, distinguishing it from other phylogenetically close Nectriaceae genera. The results indicate that R. inexpectata is distributed in wide geographic regions in southern China. Inoculation showed that R. inexpectata and Ca. crousiana caused lesions on the leaves of Ci. camphora seedlings within 6 days of inoculation, indicating that they are pathogenic to native Ci. camphora in China.

Piecing together the taxonomic puzzle of Sphaerulina

Sphaerulina species are plant pathogenic fungi causing leaf spot diseases of various hosts, including arboreous and herbaceous plants. The morphological characteristics of their asexual morphs and leaf spot symptoms are like those of Septoria spp. Due to their similar morphology, species of Sphaerulina have largely been subsumed under Septoria s. lat. A recent revision of the genus Septoria based on morphological characteristics and phylogenetic relationships resulted in the separation of Sphaerulina from Septoria. This study reveals the diversity of the genus Sphaerulina in Japan, and the species relationships based on a multigene phylogenetic analysis. Moreover, results of our phylogenetic analysis revealed seven novel species (Sph. farfugii, Sph. hydrangeicola, Sph. idesiae, Sph. lapsanastri, Sph. miurae, Sph. styracis, and Sph. viburnicola) which are described, and two species (Sep. duchesnea and Sep. nambuana) which are transferred to the genus Sphaerulina. Citation: Ujat AH, Nakashima C (2024). Piecing together the taxonomic puzzle of Sphaerulina. Fungal Systematics and Evolution 14: 171-190. doi: 10.3114/fuse.2024.14.11.

Cultivable root endophytic fungi associated with Acrocomia aculeata and its antagonistic activity against phytopathogenic oomycetes

Macaw palm (Acrocomia aculeata Jacq.) is a palm, native to Brazilian territory that stands out due to the amount of oil produced with applications in the biodiesel industry, cosmetics, and food. Its commercial exploitation in Brazil, including phytosanitary management is based on concepts and practices of regenerative agriculture, which has the responsibility of sustainable cultivation by avoiding, for example, the use of chemical pesticides. Recently, root and stem rot disease were reported in macaw palm seedlings caused by Phytophthora palmivora. Managing this plant pathogen is complex, and the chemical control of this soil-borne oomycete is not viable, in addition to the negative impact on the environment. Many microorganisms are studied and used as biological control agents (BCAs) against pathogens, among them the community of endophytic fungi associated with plants. This is a sustainable biotechnological alternative for plant disease control. The community of cultivable endophytic fungi associated with healthy roots of macaw palm was explored using the extinction cultivation technique and a screening was carried out to select potential antagonists against oomycetes through the dual culture test. Specific gene regions from the best isolates were amplified for identification. A total of 250 isolates were obtained, and 46 were selected for in vitro tests against representatives of phytopathogenic oomycetes. After tests against Phytophthora heterospora, Phytophthora palmivora, Pythium aphanidermatum, and Pythium deliense, two isolates were selected as potential antagonists. The phylogenetic analysis of selected isolates showed that they belong to two different species: Talaromyces sayulitensis COAD 3605 and Epicoccum italicum COAD 3608. The percentage of inhibition of phytopathogenic oomycetes testedwas until 82% in the antagonism tests conducted. From the 46 isolates selected, only 2 were selected which showed great antagonistic activity towards all oomycetes tested. These fungi will be used in upcoming studies that aim to determine the effectiveness of endophytes in controlling diseases caused by oomycetes in the field.

Known from trees and the tropics: new insights into the Fusarium lateritium species complex

The Fusarium lateritium species complex (FLSC) currently comprises 11 phylogenetic species, including accepted names such as F. lateritium, F. sarcochroum, and F. stilboides, which have mostly been reported in association with citrus and coffee. Many varieties were documented by Wollenweber & Reinking (1935), which is indicative of a wider diversity of species within this group. The lack of type material in some cases, especially for the older names, means that definition by molecular phylogeny is very difficult. In the present study, we examined 179 strains related to F. lateritium from different countries and substrates. Historic reference material, including representative strains from the Wollenweber & Reinking (1935) varieties were included in this study, DNA sequences were generated for comparison, and the morphology correlated with original descriptions to enable the correct application of older names. Strains were characterized by multi-gene phylogenetic analyses based on fragments of the β-tubulin (tub2), calmodulin (CaM), RNA polymerase II second largest subunit (rpb2), and translation elongation factor 1-alpha (tef1) genes, evaluation of morphological characters and host-substrate preferences. The biological species concept was tested by crossings in vitro. Strains previously identified as F. lateritium, F. stilboides, or one of their varieties based on morphology, were found to belong to 16 species in the FLSC, but also to species from six other species complexes (SC), including the F. citricola SC, F. heterosporum SC, F. incarnatum-equiseti SC, F. redolens SC, F. sambucinum SC, and the F. tricinctum SC. Eleven new phylogenetic and two biological species are described in the FLSC, and emended descriptions are provided for four previously described species. An epitype is designated for F. lateritium, and F. lateritium var. longum, a former variety within the FLSC, is lecto- and epitypified, and elevated to species level with a replacement name. Taxonomic novelties: New species: F. aurantii M.M. Costa, Sand.-Den. & Crous, F. chlamydocopiosum M.M. Costa, Sand.-Den. & Crous, F. citri-sinensis L. Zhao & J.X. Deng, F. coffeibaccae M.M. Costa, L.H. Pfenning, Sand.-Den. & Crous, F. crocatum M.M. Costa, Sand.-Den. & Crous, F. malawiense M.M. Costa, Sand.-Den. & Crous, F. microcyclum M.M. Costa, Sand.-Den. & Crous, F. oliniae M.M. Costa, Sand.-Den. & Crous; F. rufum M.M. Costa, Sand.-Den. & Crous, F. stramineum M.M. Costa, Sand.-Den. & Crous, F. velutinum M.M. Costa, Sand.-Den. & Crous, F. verruculosum M.M. Costa, Sand.-Den. & Crous; Replacement name: F. hanswilhelmii M.M. Costa, Sand.-Den. & Crous; Epitype (basionym): F. lateritium Nees, F. lateritium var. longum Wollenw.; Lectotype (basionym): F. lateritium var. longum Wollenw. Citation: Costa MM, Sandoval-Denis M, Moreira GM, Kandemir H, Kermode A, Buddie AG, Ryan MJ, Becker Y, Yurkov A, Maier W, Groenewald JZ, Pfenning LH, Crous PW (2024). Known from trees and the tropics: new insights into the Fusarium lateritium species complex. Studies in Mycology 109: 403-450. doi: 10.3114/sim.2024.109.06.

Identification and biological characteristics of Fusarium tobaccum sp. nov., a novel species causing tobacco root rot in Jilin Province, China

Fusarium wilt of tobacco (FWT), caused by Fusarium spp., has emerged as a severe threat to tobacco production in China. In all, 132 isolates of Fusarium were isolated from tobacco and pathogenic to tobacco-causing FWT in Jilin Province, China. In this study, we identified 7 of 132 isolates as a novel species Fusarium tobaccum sp. nov. Zhao Xie & Jie Gao, using multi-gene phylogenetic analyses of translation elongation factor (tef1), β-tubulin (tub2), calmodulin (cmdA), and RNA polymerase II second largest subunit (rpb2) genes, along with subtle morphological differences. Isolates of F. tobaccum sp. nov. were clustered in a distinct branch in the maximum parsimony phylogenetic tree generated from the sequences of tef1-rpb2-tub2-cmdA and can be distinguished from closely related species F. cugenangense, F. callistephi, and F. elaeidis. The morphological characteristics of F. tobaccum sp. nov. are distinct from other Fusarium species. F. tobaccum sp. nov. exhibits abundant aerial mycelia and pigment production on potato dextrose agar (PDA), microconidia with 0-1 septa, and macroconidia with 2-5 septa on carnation leaf-piece agar (CLA), and produces abundant chlamydospores on Spezieller Nährstoffarmer agar (SNA) and CLA. The mycelia of F. tobaccum exhibited optimal growth at a pH of 7.1 and a temperature of 23.6°C. Sucrose and NaNO3 significantly promoted the mycelial growth of F. tobaccum. PD medium was optimal for total sporulation. However, the sporulation ratios of the macrospores of F. tobaccum in PD, SN, and CMC were relatively low (0.48%, 2.51%, and 2.16%, respectively). These findings provided valuable insights into the morphological and biological characteristics of F. tobaccum.IMPORTANCEFusarium wilt of tobacco (FWT) is a prevalent issue in tobacco-growing regions globally, leading to significant losses in yield and quality. This study identified F. tobaccum sp. nov., a novel species of Fusarium causing FWT in China. The identification was based on multi-gene phylogenetic analyses and morphological characteristics. The effects of temperature, pH, carbon source, nitrogen source, medium, and light on the mycelial growth of F. tobaccum sp. nov. were determined. These findings might contribute to future research on the pathogenic mechanisms of this novel species and the development of strategies to control FWT.

A new leaf inhabiting ascomycete from the Jurassic (ca 170 Mya) of Yorkshire, UK, and insights into the appearance and diversification of filamentous Ascomycota

Leaf-associated fungi, the fungi that depend on leaves to sporulate, have a rich Cenozoic record, however their earlier diversity is poorly characterized. Here we describe Harristroma eboracense gen. et sp. nov., a Middle Jurassic leaf-associated fungus colonizing the leaf cuticle of Nilssonia tenuicaulis (cycadophyte). To place our newly described species into a picture of the diversification of Mesozoic fungi, we reassess fossils with leaf-associated stromata in the context of fungal molecular phylogeny. Being melanized, with radiate stromata, and on leaves, H. eboracense and other fossils from the Jurassic and earlier periods are probably related to filamentous Ascomycota in the superclass Leotiomyceta. Characters needed for further resolution of leaf-associated fungal biology and classification, such as the presence of an ostiole for spore discharge and appressoria for entry into leaf tissue first appear in the Mesozoic fossil record. Among Early Cretaceous fossils, Spataporthe taylorii represents the oldest unambiguous evidence of perithecial Sordariomycetes while Protographum luttrellii and Bleximothyrium ostiolatum are the oldest Dothideomycetes thyriothecia. Environmental observations show that broad leaved gymnosperms (especially cycadophytes) growing in warm temperate wet forests might have been the first environment for the radiation of Leotiomyceta.

Profiling of the Citrus Leaf Endophytic Mycobiota Reveals Abundant Pathogen-Related Fungal Groups

Plant endophytic microbial communities consist of many latent plant pathogens and, also, many pathogen-related species with reduced virulence. Though with a long history of co-evolution, the diversity and composition of the endophytic mycobiota, especially the pathogen-related fungal groups, has been under-investigated in Citrus (C.). Based on the amplicon sequencing of fungal internal transcribed spacer (ITS), the leaf endophytic mycobiota were profiled on citrus varieties from different citrus-producing regions. The pomelo variety shared significantly distinctive leaf mycobiota when compared to the mandarin and sweet orange; these conform to their host genetic relationships. In addition, a data set of 241 citrus-related fungi, including 171 (71%) pathogens and potential pathogens, was summarized from previous studies. Under the criteria of local BLAST (covered ITS nucleotide ≥ 150 bp, sequence identity ≥ 99%), a total of 935 fungal operational taxonomic units (OTUs) were assigned to 62 pathogen-related fungal groups, representing 14.9% of the relative abundance in the whole community. Of which, the top groups consisted of Colletotrichum gloeosporioides (mean relative abundance, 4.3%), Co. citricola and Co. karstii (2.7%), Zasmidium citri-griseum (2.4%), and Z. fructigenum (1.4%). At the genus level, the ratio of the pathogen-related fungal groups in 64% of fungal genera (16 out of 25) exceeded 50%, which are the solely or mainly occurring fungi of their genus in citrus. Our study suggests that the leaf endophytic compartment may be an important place for the growth of latent pathogens.

Arthrocatenales, a new order of extremophilic fungi in the Dothideomycetes

The widely treated order Capnodiales is one of the most important orders in the class Dothideomycetes. Recently, the order Capnodiales s. lat. was reassessed and split into seven orders (Capnodiales s. str., Cladosporiales, Comminutisporales, Mycosphaerellales, Neophaeothecales, Phaeothecales and Racodiales) based on multi-locus phylogeny, morphology and life strategies. In this study, two Arthrocatena strains isolated from sooty mould communities on the leaves of Tiliacordata and needles of Pinusnigra in southern Poland were analyzed. Multi-locus phylogenetic analyses (ITS-LSU-SSU-rpb2-tef1) along with morphological examination showed that they belong to Capnobotryellaantalyensis, which represents a sister taxon to Arthrocatenatenebrosa. Capnobotryellaantalyensis is a rock-inhabiting fungus described from Turkey. The following new combination is proposed: Arthrocatenaantalyensis. Phylogenetic analyses also showed that Arthrocatena and related genus Hyphoconis, both known previously only from rocks, form a sister lineage to orders Cladosporiales and Comminutisporales. The new order Arthrocatenales and new family Arthrocatenaceae are proposed to this clade. Representatives of this order are extremophilic fungi that live on rocks and in sooty mould communities.

Cercospora polygonatum, a New Species Causing Gray Leaf Spot Disease in Polygonatum cyrtonema

This study identified a new species (Cercospora polygonatum) that causes gray leaf spot (GLS) disease in cultivated Polygonatum cyrtonema. This fungal species was isolated from the affected region of GLS on P. cyrtonema leaves. Pathogenicity bioassays were conducted based on Koch's postulates. Morphology was examined based on the features of conidiomata, conidiogenous loci, conidia/conidiophores, and conidiogenous cells. The rDNA internal transcribed spacer region, calmodulin, translation elongation factor 1-alpha, and histone genes were subjected to phylogenetic analysis using the MrBayes tool in Phylosuite. Bootstrap support analysis for phylogenetic placement confirmed the new species, which was significantly different from the closely related species C. senecionis-walkeri and C. zeae-maydis. The morphological characteristics also supported this finding, with the conidiogenous cells of C. polygonatum being considerably shorter than those of C. senecionis-walkeri or C. zeae-maydis. In addition, C. polygonatum was distinguished by its cultural characteristics. As this fungus was isolated from P. cyrtonema, it was named C. polygonatum F.Q. Yin, M. Liu & W.L. Ma, sp. nov. The type specimen (H8-2) was preserved at the China General Microbiological Culture Collection Center. This is the first report of GLS caused by C. polygonatum on P. cyrtonema leaves in China. The current study enriches the knowledge regarding Cercospora sp., contributes to the identification of a species causing GLS in P. cyrtonema, and provides useful information for the effective management of this disease.

Pathogenicity Differentiation of Fusarium spp. Causing Fusarium Basal Rot and Wilt Disease in Allium spp

Here, 12 Fusarium strains, previously described as F. oxysporum f. sp. cepae (Foc), were examined via multi-locus sequencing of calmodulin (cmdA), RNA polymerase II second largest subunit (rpb2), and translation elongation factor 1-alpha (tef1), to verify the taxonomic position of Foc in the newly established epitype of F. oxysporum. The strains in this study were divided into two clades: F. nirenbergiae and Fusarium sp. To further determine the host specifications of the strains, inoculation tests were performed on onion bulbs and Welsh onion seedlings as potential hosts. Four strains (AC145, AP117, Ru-13, and TA) isolated from diseased onions commonly possessed the secreted in xylem (SIX)-3, 5, 7, 9, 10, 12, and 14 genes and were pathogenic and highly aggressive to onion bulbs, whereas all strains except for one strain (AF97) caused significant inhibition of Welsh onion growth. The inoculation test also revealed that the strains harboring the SIX9 gene were highly aggressive to both onion and Welsh onion and the gene was expressed during infection of both onions and Welsh onions, suggesting the important role of the SIX9 gene in pathogenicity. This study provides insights into the evolutionary pathogenicity differentiation of Fusarium strains causing Fusarium basal rot and wilt diseases in Allium species.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

Species diversity in Pseudocercospora

Species of Pseudocercospora are commonly associated with leaf and fruit spots on diverse plant hosts in sub-tropical and tropical regions. Pseudocercospora spp. have mycosphaerella-like sexual morphs, but represent a distinct genus in Mycosphaerellaceae (Mycosphaerellales, Dothideomycetes). The present study adds a further 29 novel species of Pseudocercospora from 413 host species representing 297 host genera occurring in 60 countries and designates four epitypes and one lectotype for established names. This study recognises 329 species names, with an additional 69 phylogenetic lineages remaining unnamed due to difficulty in being able to unambiguously apply existing names to those lineages. To help elucidate the taxonomy of these species, a phylogenetic tree was generated from multi-locus DNA sequence data of the internal transcribed spacers and intervening 5.8S nuclear nrRNA gene (ITS), partial actin (actA), and partial translation elongation factor 1-alpha (tef1), as well as the partial DNA-directed RNA polymerase II second largest subunit (rpb2) gene sequences. Novel species described in this study include those from various countries as follows: Australia, Ps. acaciicola from leaf spots on Acacia sp., Ps. anopter from leaf spots on Anopterus glandulosus, Ps. asplenii from leaf spots on Asplenium dimorphum, Ps. australiensis from leaf spots on Eucalyptus gunnii, Ps. badjensis from leaf spots on Eucalyptus badjensis, Ps. erythrophloeicola from leaf spots on Erythrophleum chlorostachys, Ps. grevilleae from leaf spots on Grevillea sp., Ps. lophostemonigena from leaf spots on Lophostemon confertus, Ps. lophostemonis from leaf spots on Lophostemon lactifluus, Ps. paramacadamiae from leaf spots on Macadamia integrifolia, Ps. persooniae from leaf spots on Persoonia sp., Ps. pultenaeae from leaf spots on Pultenaea daphnoides, Ps. tristaniopsidis from leaf spots on Tristaniopsis collina, Ps. victoriae from leaf spots on Eucalyptus globoidea. Brazil, Ps. musigena from leaf spots on Musa sp. China, Ps. lonicerae-japonicae from leaf spots on Lonicera japonica, Ps. rubigena leaf spots on Rubus sp. France (Réunion), Ps. wingfieldii from leaf spots on Acacia heterophylla. Malaysia, Ps. musarum from leaf spots on Musa sp. Netherlands, Ps. rhododendri from leaf spots on Rhododendron sp. South Africa, Ps. balanitis from leaf spots on Balanites sp., Ps. dovyalidicola from leaf spots on Dovyalis zeyheri, Ps. encephalarticola from leaf spots on Encephalartos sp. South Korea, Ps. grewiana from leaf spots on Grewia biloba, Ps. parakaki from leaf spots on Diospyros kaki, Ps. pseudocydoniae from leaf spots on Chaenomeles lagenaria, Ps. paracydoniae from leaf spots on Chaenomeles speciosa. Thailand, Ps. acerigena from leaf spots on Acer sp., Ps. tectonigena from leaf spots on Tectona grandis. Epitypes are designated for Cercospora bonjeaneae-rectae, Cercospora halleriae, Ps. eucleae, and an epitype as well as a lectotype for Ps. macadamiae. Results obtained in the present study contribute to a better understanding of the host specificity and distribution in Pseudocercospora spp., many of which represent important pathogens of food or fibre crops, or organisms of quarantine concern. Citation: Groenewald JZ, Chen YY, Zhang Y, Roux J, Shin H-D, Shivas RG, Summerell BA, Braun U, Alfenas AC, Ujat AH, Nakashima C, Crous PW (2024). Species diversity in Pseudocercospora. Fungal Systematics and Evolution 13: 29-89. doi: 10.3114/fuse.2024.13.03.

Characterization of QoI-Fungicide Resistance in Cercospora Isolates Associated with Cercospora Leaf Blight of Soybean from the Southern United States

Cercospora leaf blight (CLB) of soybean, caused by Cercospora cf. flagellaris, C. kikuchii, and C. cf. sigesbeckiae, is an economically important disease in the southern United States. Cultivar resistance to CLB is inconsistent; therefore, fungicides in the quinone outside inhibitor (QoI) class have been relied on to manage the disease. Approximately 620 isolates from plants exhibiting CLB were collected between 2018 and 2021 from 19 locations in eight southern states. A novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay based on two genes, calmodulin and histone h3, was developed to differentiate between the dominant species of Cercospora, C. cf. flagellaris, and C. cf. sigesbeckiae. A multilocus phylogenetic analysis of actin, calmodulin, histone h3, ITS rDNA, and transcription elongation factor 1-α was used to confirm PCR-RFLP results and identify remaining isolates. Approximately 80% of the isolates collected were identified as C. cf. flagellaris, while 15% classified as C. cf. sigesbeckiae, 2% as C. kikuchii, and 3% as previously unreported Cercospora species associated with CLB in the United States. PCR-RFLP of cytochrome b (cytb) identified QoI-resistance conferred by the G143A substitution. Approximately 64 to 83% of isolates were determined to be QoI-resistant, and all contained the G143A substitution. Results of discriminatory dose assays using azoxystrobin (1 ppm) were 100% consistent with PCR-RFLP results. To our knowledge, this constitutes the first report of QoI resistance in CLB pathogen populations from Alabama, Arkansas, Kentucky, Mississippi, Missouri, Tennessee, and Texas. In areas where high frequencies of resistance have been identified, QoI fungicides should be avoided, and fungicide products with alternative modes-of-action should be utilized in the absence of CLB-resistant soybean cultivars.

Pleoardoris graminearum, gen. et sp. nov., a new member of Pleosporales from North American Plains, its biogeography and effects on a foundation grass species

Diverse fungi colonize plant roots worldwide and include species from many orders of the phylum Ascomycota. These fungi include taxa with dark septate hyphae that colonize grass roots and may modulate plant responses to stress. We describe a novel group of fungal isolates and evaluate their effects on the grass Bouteloua gracilis in vitro. We isolated fungi from roots of six native grasses from 24 sites spanning replicated latitudinal gradients in the south-central US grasslands and characterized isolates phylogenetically using a genome analysis. We analyzed 14 isolates representing a novel clade within the family Montagnulaceae (order Pleosporales), here typified as Pleoardoris graminearum, closely related to the genera Didymocrea and Bimuria. This novel species produces asexual, light brown pycnidium-like conidioma, hyaline hyphae, and chlamydospores when cultured on quinoa and kiwicha agar. To evaluate its effects on B. gracilis, seeds were inoculated with one of three isolates (DS304, DS334, and DS1613) and incubated at 25 C for 20 d. We also tested the effect of volatile organic compounds (VOCs) produced by the same isolates on B. gracilis root and stem lengths. Isolates had variable effects on plant growth. One isolate increased B. gracilis root length up to 34% compared with uninoculated controls. VOCs produced by two isolates increased root and stem lengths (P < 0.05) compared with controls. Internal transcribed spacer ITS2 metabarcode data revealed that P. graminearum is distributed across a wide range of sites in North America (22 of 24 sites sampled), and its relative abundance is influenced by host species identity and latitude. Host species identity and site were the most important factors determining P. graminearum relative abundance in drought experiments at the Extreme Drought in the Grasslands Experiment (EDGE) sites. Variable responses of B. gracilis to inoculation highlight the potential importance of nonmycorrhizal root-associated fungi on plant survival in arid ecosystems.

Complete Genome Sequence Resource for Cercospora apii Causing Leaf Spot of Celery

Cercospora apii is an important seedborne pathogenic fungus causing severe Cercospora leaf spot of celery worldwide. Here, we first present a complete genome assembly of C. apii QCYBC from celery, based on Illumina paired-end and PacBio long-read sequencing data. The high-quality genome assembly contains 34 scaffolds with a 34.81 Mb genome size, 330 interspersed repeat genes, 114 noncoding RNAs, and 12,631 protein-coding genes. The benchmarking universal single-copy ortholog (BUSCO) analysis indicated that 98.2% of the BUSCOs were complete, whereas 0.3, 0.7, and 1.1% were duplicated, fragmented, and missing, respectively. Based on annotation, 508 carbohydrate-active enzymes, 243 cytochromes P450 enzymes, 1,639 translocators, 1,358 transmembrane proteins, and 1,146 virulence genes were identified. This genome sequence provides a valuable reference for future studies to improve understanding of the C. apii-celery pathosystem. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Nine new species of black lichenicolous fungi from the genus Cladophialophora (Chaetothyriales) from two different climatic zones of China

Lichenicolous fungi are parasites of lichens. Many of these fungi are referred to as "black fungi". A diversity of these black fungi include species that are pathogenic to humans and plants. A majority of black fungi reside in the phylum Ascomycota within the sub-classes Chaetothyriomycetidae and Dothideomycetidae. To explore the diversity of lichenicolous "black fungi" associated with lichens in China, we conducted several field surveys in the Inner Mongolia Autonomous Region and Yunnan Province between 2019 and 2020. We recovered 1,587 fungal isolates from the lichens collected during these surveys. During the preliminary identification of these isolates using the complete internal transcribed spacer (ITS), partial large subunit of nuclear ribosomal RNA gene (LSU), and small subunit of nuclear ribosomal RNA gene (SSU), we identified 15 fungal isolates from the genus Cladophialophora. However, these isolates had low sequence similarities with all known species from the genus. Therefore, we amplified additional gene regions, such as, translation elongation factor (TEF) and partial β-tubulin gene (TUB), and constructed a multi-gene phylogeny using maximum likelihood, maximum parsimony, and Bayesian inference. In our datasets, we included type sequences where available for all Cladophialophora species. Phylogenetic analyses revealed that none of the 15 isolates belonged to any of the previously described species in the genus. Therefore, using both morphological and molecular data, we classified these 15 isolates as nine new species within the genus Cladophialophora: C. flavoparmeliae, C. guttulate, C. heterodermiae, C. holosericea, C. lichenis, C. moniliformis, C. mongoliae, C. olivacea, and C. yunnanensis. The outcome from this study shows that lichens are an important refugia for black lichenicolous fungi, such as those from Chaetothyriales.

Morphological and molecular analyses reveal two new species of Microcera (Nectriaceae, Hypocreales) associated with scale insects on walnut in China

The fungal genus Microcera consists of species mostly occurring as parasites of scale insects, but are also commonly isolated from soil or lichens. In the present study, we surveyed the diversity and assess the taxonomy of entomopathogenic fungi in Sichuan Province, China. Two new species of Microcera, viz. M.chrysomphaludis and M.pseudaulacaspidis, were isolated from scale insects colonising walnut (Juglansregia). Maximum Likelihood and Bayesian Inference analyses of ITS, LSU, tef1-α, rpb1, rpb2, acl1, act, tub2, cmdA and his3 sequence data provide evidence for the validity of the two species and their placement in Nectriaceae (Hypocreales). Microcerapseudaulacaspidis primarily differs from similar species by having more septate and smaller cylindrical macroconidia, as well as DNA sequence data. Meanwhile, Microcerachrysomphaludis has elliptical, one-septate ascospores with acute ends and cylindrical, slightly curved with 4-6 septate macroconidia up to 78 µm long. Morphological descriptions with illustrations of the novel species and DNA-based phylogeny generated from analyses of multigene dataset are also provided to better understand species relationships.

Diagnosis of Soybean Diseases Caused by Fungal and Oomycete Pathogens: Existing Methods and New Developments

Soybean (Glycine max) acreage is increasing dramatically, together with the use of soybean as a source of vegetable protein and oil. However, soybean production is affected by several diseases, especially diseases caused by fungal seed-borne pathogens. As infected seeds often appear symptomless, diagnosis by applying accurate detection techniques is essential to prevent propagation of pathogens. Seed incubation on culture media is the traditional method to detect such pathogens. This method is simple, but fungi have to develop axenically and expert mycologists are required for species identification. Even experts may not be able to provide reliable type level identification because of close similarities between species. Other pathogens are soil-borne. Here, traditional methods for detection and identification pose even greater problems. Recently, molecular methods, based on analyzing DNA, have been developed for sensitive and specific identification. Here, we provide an overview of available molecular assays to identify species of the genera Diaporthe, Sclerotinia, Colletotrichum, Fusarium, Cercospora, Septoria, Macrophomina, Phialophora, Rhizoctonia, Phakopsora, Phytophthora, and Pythium, causing soybean diseases. We also describe the basic steps in establishing PCR-based detection methods, and we discuss potentials and challenges in using such assays.

A Secondary Metabolite of Cercospora sp., Associated with Rosa damascena Mill., Inhibits Proliferation, Biofilm Production, Ergosterol Synthesis and Other Virulence Factors in Candida albicans

Here we describe the antimicrobial potential of secondary metabolites, fulvic acid (F.A.) and anhydrofulvic acid (AFA), produced by RDE147, an endophyte of Rosa damascena Mill. The endophyte was identified as Cercospora piaropi by ITS and β-tubulin-based phylogenetic analyses, while chemoprofiling of the endophyte by column chromatography and spectroscopy yielded two pure compounds, F.A. and AFA. The compounds demonstrated different antimicrobial profiles, with AFA suppressing the growth of C. albicans at 7.3 µg ml^-1 IC₅₀. Further studies revealed that AFA strongly restricted the biofilm production and hyphae formation in C. albicans by down-regulating several biofilm and morphogenesis-related genes. The time-kill assays confirmed the fungicidal activity of AFA against C. albicans, killing 83.6% of the pathogen cells in 24 h at the MIC concentration, and the post-antibiotic effect (PAE) experiments established the suppression of C. albicans growth for extended time periods. The compound acted synergistically with amphotericin B and nystatin and reduced ergosterol biosynthesis by the pathogen, confirmed by ergosterol estimation and comparative expression profiling of selected genes and molecular docking of AFA with C. albicans squalene epoxidase. AFA also suppressed the expression of several other virulence genes of the fungal pathogen. The study determines the anti-C. albicans potential of AFA and its impact on the biology of the pathogen. It also indicates that Cercospora species may yield potential bioactive molecules, especially fulvic acid derivatives. However, it is imperative to conduct in vivo studies to explore this molecule's therapeutic potential further.

Amesia hispanica sp. nov., Producer of the Antifungal Class of Antibiotics Dactylfungins

During a study of the diversity of soilborne fungi from Spain, a strain belonging to the family Chaetomiaceae (Sordariales) was isolated. The multigene phylogenetic inference using five DNA loci showed that this strain represents an undescribed species of the genus Amesia, herein introduced as A. hispanica sp. nov. Investigation of its secondary metabolome led to the isolation of two new derivatives (2 and 3) of the known antifungal antibiotic dactylfungin A (1), together with the known compound cochliodinol (4). The planar structures of 1-4 were determined by ultrahigh performance liquid chromatography coupled with diode array detection and ion mobility tandem mass spectrometry (UHPLC-DAD-IM-MS/MS) and extensive 1D and 2D nuclear magnetic resonance (NMR) spectroscopy after isolation by HPLC. All isolated secondary metabolites were tested for their antimicrobial and cytotoxic activities. Dactylfungin A (1) showed selective and strong antifungal activity against some of the tested human pathogens (Aspergillus fumigatus and Cryptococcus neoformans). The additional hydroxyl group in 2 resulted in the loss of activity against C. neoformans but still retained the inhibition of As. fumigatus in a lower concentration than that of the respective control, without showing any cytotoxic effects. In contrast, 25″-dehydroxy-dactylfungin A (3) exhibited improved activity against yeasts (Schizosaccharomyces pombe and Rhodotorula glutinis) than 1 and 2, but resulted in the appearance of slight cytotoxicity. The present study exemplifies how even in a well-studied taxonomic group such as the Chaetomiaceae, the investigation of novel taxa still brings chemistry novelty, as demonstrated in this first report of this antibiotic class for chaetomiaceous and sordarialean taxa.

Fungal Diversity Associated with Thirty-Eight Lichen Species Revealed a New Genus of Endolichenic Fungi, Intumescentia gen. nov. (Teratosphaeriaceae)

Fungi from the Teratosphaeriaceae (Mycosphaerellales; Dothideomycetes; Ascomycota) have a wide range of lifestyles. Among these are a few species that are endolichenic fungi. However, the known diversity of endolichenic fungi from Teratosphaeriaceae is far less understood compared to other lineages of Ascomycota. We conducted five surveys from 2020 to 2021 in Yunnan Province of China, to explore the biodiversity of endolichenic fungi. During these surveys, we collected multiple samples of 38 lichen species. We recovered a total of 205 fungal isolates representing 127 species from the medullary tissues of these lichens. Most of these isolates were from Ascomycota (118 species), and the remaining were from Basidiomycota (8 species) and Mucoromycota (1 species). These endolichenic fungi represented a wide variety of guilds, including saprophytes, plant pathogens, human pathogens, as well as entomopathogenic, endolichenic, and symbiotic fungi. Morphological and molecular data indicated that 16 of the 206 fungal isolates belonged to the family Teratosphaeriaceae. Among these were six isolates that had a low sequence similarity with any of the previously described species of Teratosphaeriaceae. For these six isolates, we amplified additional gene regions and conducted phylogenetic analyses. In both single gene and multi-gene phylogenetic analyses using ITS, LSU, SSU, RPB2, TEF1, ACT, and CAL data, these six isolates emerged as a monophyletic lineage within the family Teratosphaeriaceae and sister to a clade that included fungi from the genera Acidiella and Xenopenidiella. The analyses also indicated that these six isolates represented four species. Therefore, we established a new genus, Intumescentia gen. nov., to describe these species as Intumescentia ceratinae, I. tinctorum, I. pseudolivetorum, and I. vitii. These four species are the first endolichenic fungi representing Teratosphaeriaceae from China.

The diversity of cultivable endophytic fungi of the sand coast plant Ipomoeapes-caprae in Taiwan

Background

Ipomoeapes-caprae is a plant of sand coasts and it can tolerate stresses, such as high salinity, strong wind and sand movements and lack of nutrients. It plays an important role in coast protection and preventing erosion. Fungal endophytes show high biodiversity and have a strong influence on the survival of plants under different stress factors. Although this plant is important for sand coast ecosystems, little is known about the associated fungi. In this study, we isolated and identified endophytic fungi of Ipomoeapes-caprae, a dominant plant along the shore of Taiwan. The dataset contains 896 records, which correspond to 177 species. The geographical scope of the dataset covers the northern subtropical area of the main island of Taiwan, with its sand coasts in New Taipei, Taoyuan, Hsinchu and Taichung and two botanical gardens in Taipei and Taichung. The detailed original data of fungal diversity are rarely publicly shared under strictly formalised and, thus, reusable standards. As an example for such an approach, the complete occurrence dataset was made available in the Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF) under Version 1.13, Taiwan Biodiversity Information Facility (TaiBIF) https://doi.org/10.15468/9h9rcg. In this first data paper on endophytic fungi, the scientific name and associated DNA sequence in the dataset were directly linked to other free online resource (Index Fungorum, GenBank), which shows the potential of GBIF for linking together different online data repositories.

New information

We describe a dataset, in which the diversity of endophytic fungi of the sand coast plant Ipomoeapes-caprae in Taiwan was investigated.

First report flat peach fruit rot caused by Fusarium fujikuroi in China

Flat peach (Prunus persica L. Batsch. var. compressa Bean) is a distinctive peach variety with flat shape. It is well known for its high nutritional value and pleasant flavor, and has become the primary cultivar in Shengzhou city, Zhejiang province, China. In July 2021, we discovered that 8%-10% of flat peach (data gained from a survey of fifteen trees in each orchard) fruits in three orchards (about 2.6 ha) had a fungal disease in Jinting Town, Shengzhou. The infected fruit by this pathogen showed soft, brown, and sunken lesions, accompanied by a sour odor and white mycelia. For pathogen isolation, ten infected fruits were surface sterilized (75% ethanol for 30 s and 2.0% NaClO for 3 min), then rinsed with sterile distilled water three times. The tissues from the margin of lesions were cut into 0.6×0.6 cm pieces and transferred to potato dextrose agar (PDA) medium containing 30.0 μg/mL chloramphenicol. The plates were incubated at 25 °C for 5 days in the dark. Mycelia growing from tissues were subcultured onto fresh PDA medium to get a pure isolate, which formed dense white hyphae after 4 days. The average growth rate of mycelium on PDA medium was 3.4 ± 0.2 mm/d, and the colonies were pale purple after 5 days. Macroconidia was slender, slightly curved, almost 2 to 3 septa, with a bend and tapering apical cell and poorly developed foot cell, and the size was 4.5 to 16.9 × 1.8 to 4.0 μm (n= 50) μm. No microconidia and chlamydospores were observed. This isolate's morphological and cultural characteristics were close to Fusarium fujikuroi (Leslie and Summerell. 2006). To further get the phylogenetic evidence, the nuclear ribosomal internal transcribed spacer region (ITS) and translation elongation factor-1 (TEF-1α) genes of three representative isolations were amplified by primers ITS1 (F:5'-GGAAGTAAAAGTCGTAACAAGG-3') /ITS4 (R5'-TCCTCCGCTTATTGATATGC-3') (Groenewald et al. 2013), and EF1-728F (5'-TACAARTGYGGTGGTATYGACA-3')/ EF1-986R (5'-ACNGACTTGACYTCAGTRGT-3') (Carbone and Kohn. 1999), respectively. The amplified sequences were submitted to Genbank with accession numbers OP223318 for the IST and OP394152 for the ETF-1α region. Blastn results indicated that the ITS and TEF-1α sequences from the isolated strain shared 96.25% and 98.32% similarity with two strains of F. fujikuroi (GenBank Accession No. MF281286.2, and MK311296.1). The isolates were clustered with F. fujikuroi clade (Supplementary Fig.1 and Supplementary Fig.2), consistent with the morphological identification. To evaluate Koch's postulates, 20μL of spore suspension (1×106 spores/mL) were inoculated into ten healthy flat peach fruits with sterile syringes, while another ten healthy fruits were injected with sterilized water as controls. All fruits were kept in sealed plastic boxes at 25 °C with 90% relative humidity. All inoculated fruits showed symptoms similar to those of naturally infected fruits, while uninoculated fruits remained healthy after 4 days. In addition, F. fujikuroi was an important pathogen causing bakanae disease in rice (Hou et al. 2017). This pathogen was also reported to cause Lilium lacifolium Thunb bulb rot (Fang et al. 2022) and cause root rot in peanuts in China (Sun et al. 2022). However, to the best of our knowledge, this is the first record of F. fujikuroi causing fruit rot in flat peach in China. The discovery will provide helpful information about flat peach rot disease management.

Genome sequencing and annotation of Cercospora sesami, a fungal pathogen causing leaf spot to Sesamum indicum

Cercospora sesami is a plant pathogen that causes leaf spot disease in sesame plants worldwide. In this study, genome sequence assembly of C. sesami isolate Cers 52-10 (MCC 9069) was generated using native paired-end and mate-pair DNA sequencing based on the Illumina HiSeq 2500 platform. The genome assembly of C. sesami is 34.3 Mb in size with an N50 of 26,222 bp and an average GC content of 53.02%. A total number of 10,872 genes were predicted in this study, out of which 9,712 genes were functionally annotated. Genes assigned to carbohydrate-active enzyme classes were also identified during the study. A total of 80 putative effector candidates were predicted and functionally annotated. The C. sesami genome sequence is available at DDBJ/ENA/GenBank, and other associated information is submitted to Mendeley's data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03468-4.

Five Previously Unrecorded Fungal Species Isolated from Marine Plastic Wastes in South Korea

Plastic wastes have a negative impact on marine environments; however, they can be used as carbon sources and habitats by certain microbes. Microbes in the marine plastisphere can migrate worldwide through the ocean and cause serious environmental problems when they encounter suitable environments. Therefore, efforts to investigate the microbes inhabiting the marine plastisphere are increasing. In the present study, fungal strains were isolated from plastic wastes buried in Korean sea sands and mudflats and identified using molecular and morphological analyses. Five species were identified that were previously unrecorded from South Korea: Cladosporium funiculosum, Neosetophoma poaceicola, Neosetophoma rosigena, Parasarocladium gamsii, and Trichoderma fomiticola. Their molecular phylogenies and morphological characteristics are described in this study.

Plastic-inhabiting fungi in marine environments and PCL degradation activity

Plastic waste has a negative impact on marine ecosystems and the quantity of this source of anthropogenic pollution continues to increase. Several studies have investigated plastic biodegradation using various microorganisms. In this study, we isolated fungi from polyethylene terephthalate (PET) waste on Korean seacoasts and evaluated their ability to degrade plastic by comparing the diameters of the clear zones they formed on polycaprolactone (PCL) agar. We isolated 262 strains from 47 plastic waste sources and identified 108 fungal species via molecular methods. The PCL agar assay revealed that 87 species presented with varying degrees of PCL degradation capacity. Among them, certain fungal species were strong PCL degraders. The present study demonstrated the possibility that some fungi inhabiting plastic could potentially degrade it in the marine environment. We believe that the discoveries made herein lay theoretical and practical foundations for the development of novel bioremediation systems for marine plastispheres and help mitigate the environmental pollution issues related to plastic wastes.

Detection of Anthracnose in Strawberry and Methods of Etiological Diagnosis

Anthracnose of strawberry caused by Colletotrichum fungi is a dangerous disease associated with serious damage in berry plantations. Colletotrichum nymphaeae, C. lineola, and C. godetiae have been found in Russian and international planting material of strawberry plants. The cultural and morphological characteristics are described for the isolates and nucleotide ITS1-5.8S-ITS2 sequences of fragments received are identified. It is shown that the fragments of glyceraldehyde 3-phosphate dehydrogenase and actin genes can be used to efficiently differentiate the C. lineola species from the closely related С. dematium. Two diagnostic test systems for acutatum complex identification are compared. The studied test systems do not demonstrate any false-positive results; the prepared set of С. acutatum complex-RT (ZAO Sintol) shows specificity only for the C. nymphaeae and C. fioriniae species and turned out to be nonspecific to the C. godetiae species included in the acutatum complex. The test system elaborated by Garrido et al. is found to be highly sensitive and specific to the target species of the acutatum complex.

Soil-borne Calonectria (Hypocreales, Nectriaceae) associated with Eucalyptus plantations in Colombia

Eucalyptus spp. are widely planted in Colombia as an important component of a growing paper and pulp industry. Leaf and shoot blight caused by Calonectria spp. was one of the first disease problems to emerge in these plantations. A survey of Eucalyptus plantations in four forestry regions of Colombia during 2016 resulted in a large number of Calonectria isolates from soil samples collected in the understories of trees having symptoms of Calonectria leaf and shoot blight. The aim of this study was to identify and resolve the phylogenetic relationships for these isolates using DNA sequence comparisons of six gene regions as well as morphological characters. From a collection of 107 isolates, seven Calonectria species residing in three species complexes were identified. Two of these represented undescribed species, namely C.exiguispora sp. nov. and C.guahibo sp. nov. Calonectriaparvispora and C.spathulata were the most commonly isolated species, each of which accounted for approximately 30% of the isolates. The results suggest that Colombia has a wide diversity of Calonectria spp. and that these could challenge Eucalyptus plantation forestry in the future.

Trichocladium solani sp. nov.—A New Pathogen on Potato Tubers Causing Yellow Rot

A new species, Trichocladium solani, was isolated from potato (Solanum tuberosum L.) tubers from Russia. The species has no observed teleomorph and is characterized morphologically by non-specific Acremonium-like conidia on single phialides and chains of swollen chlamydospores. Phylogenetic analysis placed the new species in a monophyletic clade inside the Trichocladium lineage with a high level of support from a multi-locus analysis of three gene regions: ITS, tub2, and rpb2. ITS is found to be insufficient for species delimitation and is not recommended for identification purposes in screening studies. T. solani is pathogenic to potato tubers and causes lesions that look similar to symptoms of Fusarium dry rot infection but with yellowish or greenish tint in the necrotized area. The disease has been named “yellow rot of potato tubers”.

Acrophialophora jodhpurensis: an endophytic plant growth promoting fungus with biocontrol effect against Alternaria alternata

In this study, efficiency of the endophytic fungal isolate Msh5 was evaluated on promoting tomato plant growth and controlling Alternaria alternata, the causal agent of early blight in tomatoes. Morphological and molecular (ITS and tub2 sequences) analyses revealed that the fungal isolate, Msh5, was Acrophialophora jodhpurensis (Chaetomium jodhpurense Lodha). This beneficial fungus was capable of producing indole-3-acetic acid (IAA), urease, siderophore, extracellular enzymes, and solubilized phosphate. Under laboratory conditions, the Msh5 isolate of A. jodhpurensis inhibited A. alternata growth in dual culture, volatile and non-volatile metabolites assays. The supernatant of this endophytic fungus was capable of reducing spore germination and altering the hyphal structure of A. alternata and the spores produced germ tubes showed vacuolization and abnormal structure compared to the control. Also, the effect of A. jodhpurensis on plant growth parameters (such as shoot and root weight and length) and suppressing A. alternata was investigated in vivo via seed inoculation with spores of A. jodhpurensis using 1% sugar, 0.5% carboxymethyl cellulose (CMC) or 0.5% molasses solution as stickers. Colonization of tomato roots by the endophytic fungus resulted in significant increasing plant growth parameters and reduction in the progress of the diseases caused by A. alternata compared to the controls. Among the different coating materials used as stickers, sugar was found to be the most effective for enhancing plant growth parameters and decreasing the disease progress. Therefore, A. jodhpurensis isolate Msh5 can be suggested as a potential biofertilizer and biocontrol agent for protecting tomato plants against A. alternata.

Mycoparasitism capability and growth inhibition activity of Clonostachys rosea isolates against fungal pathogens of grapevine trunk diseases suggest potential for biocontrol

The present study aimed to examine the capability of Clonostachys rosea isolates as a biological control agent against grapevine trunk diseases pathogens. Five C. rosea and 174 pathogenic fungal strains were isolated from grafted grapevines and subjected to in vitro confrontation tests. Efficient antagonism was observed against Eutypa lata and Phaeomoniella chlamydospora while mycoparasitism was observed to the pathogens of Botryosphaeria dothidea and Diaporthe spp. pathogens in in vitro dual culture assays. The conidia production of the C. rosea isolates were also measured on PDA plates. One isolate (19B/1) with high antagonistic capabilities and efficient conidia production was selected for in planta confrontation tests by mixing its conidia with the soil of Cabernet sauvignon grapevine cuttings artificially infected with B. dothidea, E. lata and P. chlamydospora. The length and/or the incidence of necrotic lesions caused by E. lata and P. chlamydospora at the inoculation point were significantly decreased after a three months incubation in the greenhouse on cuttings planted in soils inoculated with the conidia of strain 19B/1, while symptom incidence and severity were unaffected in the case of the pathogen B. dothidea. Based on the above results, we consider C. rosea a promising biological control agent against some grapevine trunk diseases.

Development of a Novel Diagnostic Tool for Cercospora Species Based on BOX-PCR System

The genus Cercospora contains many devastating plant pathogens linked to leaf spot diseases afflicting various plants. Identification of Cercospora species based on morphology or host plant association has proven unreliable due to simple morphology and wide host range in many cases; hence, multi-gene DNA sequence data are essential for accurate species identification. Considering the complexity and cost involved in application of multi-locus DNA phylogenetic approaches for species delineation in Cercospora; rapid and cost-effective methods are urgently needed for species recognition. In this study, we applied rep-PCR (repetitive-sequence based polymerase chain reaction) fingerprinting methods referred to as BOX-PCR to differentiate species of Cercospora. Cluster analysis of the banding patterns of 52 Cercospora strains indicated the ability of BOX-PCR technique using BOXA1R primer to generate species-specific DNA fingerprints from all the tested strains. Since this technique was able to discriminate between all the 20 examined Cercospora species during this study, which corresponded well to the species identified based on multi-gene DNA sequence data, our findings revealed the efficiency of BOX-PCR system as a suitable complementary method for molecular identification of the genus Cercospora at species level.

First Report of Cercospora apii sensu lato 'sp. Q' Leaf Spot on Hop in Brazil

Hop - Humulus lupulus (Cannabaceae) - is an important and ancient, herbaceous, temperate, perennial crop. It is a vine which, although having other uses, is cultivated predominantly for the brewing industry (Laws 2013). Cultivation of hops in Brazil is relatively new and has increased in the last twenty years. There is only one published record of a fungal disease affecting hop in Brazil - powdery mildew (Fagherazzi et al 2021). In January 2021, leaf spots appeared on all eight hops plants ithe collection maintained in the Infectarium, a disease demonstration garden on the campus of the Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais, Brazil (https://www.infectario.ufv.br/). Symptoms were small, sub-circular to irregular spots, up to 5 mm, with a whitish to grayish center, surrounded by a dark brown necrotic margin, followed by a narrow yellowish outer margin. Older lesions became larger, grayish-brown, coalesced leading to extensive necrosis and stem dieback. A sample was collected, dried in a plant press, and deposited in the Herbarium of UFV (Acc. No VIC 47534). A dematiaceous fungus was found sporulating in the center of the lesions, when examined with a dissecting microscope. Fungal structures were scraped with a scalpel, mounted in lactoglycerol and observed with a light microscope (Olympus BX51). A pure culture was obtained after conidia were transferred onto PDA plates with a sterile fine-pointed needle. A representative isolate was deposited in the culture collection of the UFV (COAD 3368). The fungus had the following morphology: conidiophores cylindrical, geniculate, proliferating sympodially, 53 to 380 µm × 3 to 6.5 µm, 3 to 15-septate, smooth, with thickened and dark conidial scars, brown; conidia acicular to filiform, 47 to 210 µm × 2.5 to 5 µm, 3 to 17-septate, thin‑walled, smooth, with thickened and dark hila, hyaline. This combination is typical of Cercospora apii sensu lato, as described by Crous and Braun (2003). Genomic DNA was extracted from a 7-day-old culture of COAD 3368 and three loci were PCR amplified, namely: actin (ACT), with 512-F and 783-R primers; calmodulin (CAL), using the primers 228F and 2Rd; and histone H3 gene (HIS3), with the primers CYLH3F and CYLH3R. PCR products were sequenced by Macrogen (Seoul, South Korea) and the resulting sequences were deposited in GenBank (OM677624, OM677625 and OM677626, respectively). A multilocus Bayesian phylogenetic grouped COAD 3368 with Cercospora 'sp. Q' (Groenewald et al. 2013). This is a yet unresolved species complex within C. apii. Six 6‑month‑old healthy hop plants (cv. Cascade) were sprayed with a COAD 3368 conidial suspension (105 conidia/ mL) whereas another group of six plants was sprayed with sterile distilled water, serving as controls. Plants were placed in a dew chamber for 5 days and then transferred to a greenhouse bench, where they were observed daily. Thirty days after inoculation, symptoms similar to those observed in the field had developed on all inoculated plants, whereas control plants remained healthy. The fungus growing on inoculated hops produced typical Cercospora conidiophores and conidia. Upon reisolation, pure cultures with the same morphology of COAD 3368 were obtained. There are no previous records of Cercospora 'sp. Q' on hops worldwide. Fungi in Cercospora 'sp. Q' are known to have a broad host-range. A previous record of Cercospora 'sp. Q' leaf spots was published from its observation on Dioscorea cayennensis in the Infectarium (Torres et al. 2016). Damage to the hop plants was severe and it is possible that Cercospora leaf spot will become an emerging threat to commercial hop plantations in Brazil.

Genera of phytopathogenic fungi: GOPHY 4

This paper is the fourth contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions and information about the pathology, distribution, hosts and disease symptoms, as well as DNA barcodes for the taxa covered. Moreover, 12 whole-genome sequences for the type or new species in the treated genera are provided. The fourth paper in the GOPHY series covers 19 genera of phytopathogenic fungi and their relatives, including Ascochyta, Cadophora, Celoporthe, Cercospora, Coleophoma, Cytospora, Dendrostoma, Didymella, Endothia, Heterophaeomoniella, Leptosphaerulina, Melampsora, Nigrospora, Pezicula, Phaeomoniella, Pseudocercospora, Pteridopassalora, Zymoseptoria, and one genus of oomycetes, Phytophthora. This study includes two new genera, 30 new species, five new combinations, and 43 typifications of older names. Taxonomic novelties: New genera: Heterophaeomoniella L. Mostert, C.F.J. Spies, Halleen & Gramaje, Pteridopassalora C. Nakash. & Crous; New species: Ascochyta flava Qian Chen & L. Cai, Cadophora domestica L. Mostert, R. van der Merwe, Halleen & Gramaje, Cadophora rotunda L. Mostert, R. van der Merwe, Halleen & Gramaje, Cadophora vinacea J.R. Úrbez-Torres, D.T. O'Gorman & Gramaje, Cadophora vivarii L. Mostert, Havenga, Halleen & Gramaje, Celoporthe foliorum H. Suzuki, Marinc. & M.J. Wingf., Cercospora alyssopsidis M. Bakhshi, Zare & Crous, Dendrostoma elaeocarpi C.M. Tian & Q. Yang, Didymella chlamydospora Qian Chen & L. Cai, Didymella gei Qian Chen & L. Cai, Didymella ligulariae Qian Chen & L. Cai, Didymella qilianensis Qian Chen & L. Cai, Didymella uniseptata Qian Chen & L. Cai, Endothia cerciana W. Wang. & S.F. Chen, Leptosphaerulina miscanthi Qian Chen & L. Cai, Nigrospora covidalis M. Raza, Qian Chen & L. Cai, Nigrospora globospora M. Raza, Qian Chen & L. Cai, Nigrospora philosophiae-doctoris M. Raza, Qian Chen & L. Cai, Phytophthora transitoria I. Milenković, T. Májek & T. Jung, Phytophthora panamensis T. Jung, Y. Balci, K. Broders & I. Milenković, Phytophthora variabilis T. Jung, M. Horta Jung & I. Milenković, Pseudocercospora delonicicola C. Nakash., L. Suhaizan & I. Nurul Faziha, Pseudocercospora farfugii C. Nakash., I. Araki, & Ai Ito, Pseudocercospora hardenbergiae Crous & C. Nakash., Pseudocercospora kenyirana C. Nakash., L. Suhaizan & I. Nurul Faziha, Pseudocercospora perrottetiae Crous, C. Nakash. & C.Y. Chen, Pseudocercospora platyceriicola C. Nakash., Y. Hatt, L. Suhaizan & I. Nurul Faziha, Pseudocercospora stemonicola C. Nakash., Y. Hatt., L. Suhaizan & I. Nurul Faziha, Pseudocercospora terengganuensis C. Nakash., Y. Hatt., L. Suhaizan & I. Nurul Faziha, Pseudocercospora xenopunicae Crous & C. Nakash.; New combinations: Heterophaeomoniella pinifoliorum (Hyang B. Lee et al.) L. Mostert, C.F.J. Spies, Halleen & Gramaje, Pseudocercospora pruni-grayanae (Sawada) C. Nakash. & Motohashi., Pseudocercospora togashiana (K. Ito & Tak. Kobay.) C. Nakash. & Tak. Kobay., Pteridopassalora nephrolepidicola (Crous & R.G. Shivas) C. Nakash. & Crous, Pteridopassalora lygodii (Goh & W.H. Hsieh) C. Nakash. & Crous; Typification: Epitypification: Botrytis infestans Mont., Cercospora abeliae Katsuki, Cercospora ceratoniae Pat. & Trab., Cercospora cladrastidis Jacz., Cercospora cryptomeriicola Sawada, Cercospora dalbergiae S.H. Sun, Cercospora ebulicola W. Yamam., Cercospora formosana W. Yamam., Cercospora fukuii W. Yamam., Cercospora glochidionis Sawada, Cercospora ixorana J.M. Yen & Lim, Cercospora liquidambaricola J.M. Yen, Cercospora pancratii Ellis & Everh., Cercospora pini-densiflorae Hori & Nambu, Cercospora profusa Syd. & P. Syd., Cercospora pyracanthae Katsuki, Cercospora horiana Togashi & Katsuki, Cercospora tabernaemontanae Syd. & P. Syd., Cercospora trinidadensis F. Stevens & Solheim, Melampsora laricis-urbanianae Tak. Matsumoto, Melampsora salicis-cupularis Wang, Phaeoisariopsis pruni-grayanae Sawada, Pseudocercospora angiopteridis Goh & W.H. Hsieh, Pseudocercospora basitruncata Crous, Pseudocercospora boehmeriigena U. Braun, Pseudocercospora coprosmae U. Braun & C.F. Hill, Pseudocercospora cratevicola C. Nakash. & U. Braun, Pseudocercospora cymbidiicola U. Braun & C.F. Hill, Pseudocercospora dodonaeae Boesew., Pseudocercospora euphorbiacearum U. Braun, Pseudocercospora lygodii Goh & W.H. Hsieh, Pseudocercospora metrosideri U. Braun, Pseudocercospora paraexosporioides C. Nakash. & U. Braun, Pseudocercospora symploci Katsuki & Tak. Kobay. ex U. Braun & Crous, Septogloeum punctatum Wakef.; Neotypification: Cercospora aleuritis I. Miyake; Lectotypification: Cercospora dalbergiae S.H. Sun, Cercospora formosana W. Yamam., Cercospora fukuii W. Yamam., Cercospora glochidionis Sawada, Cercospora profusa Syd. & P. Syd., Melampsora laricis-urbanianae Tak. Matsumoto, Phaeoisariopsis pruni-grayanae Sawada, Pseudocercospora symploci Katsuki & Tak. Kobay. ex U. Braun & Crous. Citation: Chen Q, Bakhshi M, Balci Y, Broders KD, Cheewangkoon R, Chen SF, Fan XL, Gramaje D, Halleen F, Horta Jung M, Jiang N, Jung T, Májek T, Marincowitz S, Milenković T, Mostert L, Nakashima C, Nurul Faziha I, Pan M, Raza M, Scanu B, Spies CFJ, Suhaizan L, Suzuki H, Tian CM, Tomšovský M, Úrbez-Torres JR, Wang W, Wingfield BD, Wingfield MJ, Yang Q, Yang X, Zare R, Zhao P, Groenewald JZ, Cai L, Crous PW (2022). Genera of phytopathogenic fungi: GOPHY 4. Studies in Mycology 101: 417-564. doi: 10.3114/sim.2022.101.06.

First report of Leaf Spot Caused by Paramyrothecium foliicola on Tomato (Solanum lycopersicum) in China

Tomato (Solanum lycopersicum) is a staple vegetable across the world. In October 2019, leaf spots were observed on tomato (cv. Tianmi) in a greenhouse in JiZhou District Tianjin, China(117°10 'E; 39°55 'N). Symptoms initially appeared as small brown spots, which gradually expanded and turned into circular, oval or irregular spots (some spots with distinct concentric zones). In severe cases, some spots coalesced and eventually covered the whole leaf. Disease incidence ranged between 12 and 18%. Twenty symptomatic leaves from five plants were collected and cut into small pieces, surface disinfested in 2% NaClO for 60 s, rinsed three times in sterile water, and subsequently plated on potato dextrose agar (PDA). Plates were incubated at 25°C in the dark for 7 days. A total of 102 isolates were obtained and 92 isolates had the same morphology. Colonies were initially white with abundant aerial mycelia and formed sporodochia with conidial masses in olivaceous green concentric rings. All isolates formed single-celled, hyaline, and rod-shaped conidia were 4.91 to 7.43 (avg. 6.53±0.72) × 1.41 to 2.45 （avg. 2.11±0.30）μm with rounded ends (n=50). Conidiophores were highly branched. These characteristics resembled a Paramyrothecium-like fungus (Lombard et al. 2016). The genomic DNA of three representative single-spored isolates TJJXPF1-3 were extracted and the internal transcribed spacer (ITS) region, β-tubulin (tub2), large subunit ribosomal RNA (LSU), calmodulin (cmdA) and translation elongation factor 1-alpha (tef1) genes were amplified and sequenced using the primer pairs ITS4/ITS5 (White et al. 1990), Bt2a/Bt2b (Glass and Donaldson 1995), LR0R/LR5 (Rehner and Samuels 1995; Vilgalys and Hester 1990), CAL-228F/CAL2Rd (Carbone and Kohn 1999; Groenewald et al. 2013) and EF1-728F/EF2 (O'Donnell et al. 1998), respectively. All sequences were deposited in GenBank (ITS: MW463444, OM368178, OM368179; tub2: MW269542，OM714930，OM714931; LSU: OM349050, OM397398, OM390582; cmdA: MW280443, OM350474, OM350476; tef1: MW560083, OM350475, OM350477). BLASTN analysis showed 99.3-100% similarity with reference isolate QB1 of P. foliicola (MK335967, MT415353, MT415362, MT415356 and MT415359). Multilocus phylogenetic analysis showed that TJJXPF1-3 best grouped with the P. foliicola clade, which was identified by morphological characteristics and phylogenetic analysis. To fulfill Koch's postulates, pathogenicity tests were conducted by spray-inoculation with a conidial suspension of isolate TJJXPF1 prepared with distilled water (1×105 conidia/mL) on five 45-day old tomato plants. Three healthy plants were sprayed with sterile water as control. All treatments were incubated in an artificial climate chamber (25°C, 80% RH, 12h light/12h dark ). After two weeks, leaf spots were observed on all inoculated plants, which were similar to those in the greenhouse of JiZhou District, while control plants remained asymptomatic. Additionally, the pathogens were reisolated from symptomatic leaves and three representative isolates TJJXPF4-6 were identified as P. foliicola. The pathogenicity tests were repeated thrice. To our knowledge, this is the first report of leaf spot caused by P. foliicola on tomato in China. This disease could be a serious threat to tomato production in the future. Our findings will help to differentiate this disease from other leaf spot-like diseases and develop disease control strategies.

First Report of Halo Blight on Hop Caused by Diaporthe humulicola in New York

In late July and August 2015, foliar disease was observed in three hop (Humulus lupulus; unknown cultivars) yards in Ontario, Otsego, and Putnam counties, New York (NY). Disease incidence ranged between 70 and 90% of plants, and up to 25% of the leaves per plant were affected. Leaf symptoms were large, necrotic patches with a chlorotic halo (2 to 10 cm diam.). Leaves and dry, easily shattered cones were placed at high humidity for 10 days. Pycnidia were abundant in leaf lesions which extruded conidia. Pycnidia were also observed on cone bracts and bracteoles. Fifteen isolations were made from each yard by placing a pycnidium onto 2% water agar + 0.02% (w/v) ampicillin. Colonies were hyphal tipped and transferred to potato dextrose agar (PDA) before incubation at 20°C with a 12-h photoperiod. Colonies on PDA had flat mycelia and were white to cream in color. The isolation frequency was 100%. To induce sporulation, five isolates were grown on PDA with autoclaved alfalfa stems for 7 to 10 days. Alpha conidia were hyaline, and oval with obtuse ends. Mean alpha conidial dimensions were (n = 20): 9.1 m × 3.4 µm (BE1; Ontario Co.); 11.8 × 3.8 µm (BE34; Ontario Co.); 9.6 × 4.1 µm (BE10; Ontario Co.); 10.2 × 3.7 µm (BE52; Otsego Co.); and 10.3 × 3.6 µm (BE69; Putnam Co.). Beta conidia were not observed. DNA was extracted and PCR performed to amplify the internal transcribed spacer (ITS) region (primers ITS1/ITS4; White et al. 1990), translation elongation factor 1-α (TEF; EF1-728F/EF1-986R; Carbone and Kohn 1999), a partial region of β-tubulin (TUB; Bt2a/Bt2b; Glass and Donaldson 1995), a partial region of histone 3 (H3) (H3; CYLH3F/H3-1b Crous et al. 2004), and calmodulin (CAL; CAL-228F/CAL2Rd; Groenewald et al. 2013) genes. For all NY isolates, sequence similarity was >99% to D. humulicola CT2018-3 for the ITS region, and TEF, HIS, and CAL genes. Sequence similarity to CT2018-3 for the TUB region ranged from 86.96% (BE-1) to 96.15% (BE-10). . Analyses with the ITS, TEF, CAL, and HIS sequences supported our identification of the NY isolates as D. humulicola. Sequences were deposited in GenBank (OM370960 to OM370984). For pathogenicity testing, BE-34 and BE-69 were grown on PDA + autoclaved alfalfa stems at room temperature and a 12-h photoperiod for 10 days. Conidia were harvested by flooding the plate with sterile water. Conidial concentration was quantified, and the inoculum suspension diluted to ~5  105 (+ 0.01% polysorbate-20)/ml. Five cv. Cascade plants were sprayed with inoculum until run-off and covered with a plastic bag for 72 h. Non-inoculated control plants were sprayed with 0.01% polysorbate-20 and bagged. Plants were placed in a misting chamber and exposed to alternating 25°C light/18°C dark with a 16 h photoperiod. Mist was applied for 1 h daily. Necrotic lesions like the field specimens were observed on all inoculated plants after 28 days with no symptoms on control plants. Diseased leaves were detached and placed in a humid chamber for 2 days, and pycnidia observed in lesions. The reisolation frequency of D. humulicola was 100%. Conidia from the isolates had similar morphology to the original isolates. This is the first report of halo blight caused by D. humulicola on hop in NY. Halo blight has been reported on hop and associated with significant yield loss through cone shattering in MI (Higgins et al. 2021), CT (Allan-Perkins et al. 2020), and Quebec, Canada (Hatlen et al. 2021). Research is needed to determine if management is warranted.

Identification and Pathogenicity of Paramyrothecium Species Associated with Leaf Spot Disease in Northern Thailand

Species of Paramyrothecium that are reported as plant pathogens and cause leaf spot or leaf blight have been reported on many commercial crops worldwide. In 2019, during a survey of fungi causing leaf spots on plants in Chiang Mai and Mae Hong Son provinces, northern Thailand, 16 isolates from 14 host species across nine plant families were collected. A new species Paramyrothecium vignicola sp. nov. was identified based on morphology and concatenated (ITS, cmdA, rpb2, and tub2) phylogeny. Further, P. breviseta and P. foliicola represented novel geographic records to Thailand, while P. eichhorniae represented a novel host record (Psophocarpus sp., Centrosema sp., Aristolochia sp.). These species were confirmed to be the causal agents of the leaf spot disease through pathogenicity assay. Furthermore, cross pathogenicity tests on Coffea arabica L., Commelina benghalensis L., Glycine max (L.) Merr., and Dieffenbachia seguine (Jacq.) Schott revealed multiple host ranges for these pathogens. Further research is required into the host-pathogen relationship of Paramyrothecium species that cause leaf spot and their management. Biotic and abiotic stresses caused by climate change may affect plant health and disease susceptibility. Hence, proper identification and monitoring of fungal communities in the environment are important to understand emerging diseases and for implementation of disease management strategies.

High-Quality Genome Assembly of Olea europaea subsp. cuspidata Provides Insights Into Its Resistance to Fungal Diseases in the Summer Rain Belt in East Asia

The olive tree (Olea europaea L.) is the most iconic fruit crop of the Mediterranean Basin. Since the plant was introduced to China in the 1960s, the summer rain climate makes it susceptible to pathogens, leading to some olive diseases. Olea europaea L. subsp. cuspidata is natively distributed in the Yunnan province of China. It has a smaller fruit size, lower oil content, and higher resistance compared to subsp. europaea, which makes subsp. cuspidata a critical germplasm resource to be investigated. Here, a high-quality genome of subsp. cuspidata with 1.38 Gb in size was assembled and anchored onto 23 pseudochromosomes with a mounting rate of 85.57%. It represents 96.6% completeness [benchmarking universal single-copy orthologs (BUSCO)] with a contig N50 of 14.72 Mb and a scaffold N50 of 52.68 Mb, which shows a significant improvement compared with other olive genomes assembled. The evaluation of the genome assembly showed that 92.31% of resequencing reads and an average of 96.52% of assembled transcripts could be aligned to the assembled genome. We found that a positively selected gene, evm.model.Chr16.1133, was shared with the results of transcriptome analysis. This gene belongs to the susceptible gene and negatively regulates the disease resistance process. Furthermore, we identified the Cercospora genus which causes the leaf spot disease in the infected leaves. The high-quality chromosome-level genomic information presented here may facilitate the conservation and utilization of germplasm resources of this subspecies and provide an essential genetic basis for further research into the differences in oil content and resistance between subsp. cuspidata and europaea.