Novel multilocus sequence typing scheme reveals high genetic diversity of human pathogenic members of the Fusarium incarnatum-F. equiseti and F. chlamydosporum species complexes within the United States

Evaluation of the Genetic Diversity, Haplotype, and Virulence of Fusarium oxysporum f. sp. vasinfectum Field Isolates from Alabama

The United States is the third largest producer of cotton and the largest exporter of cotton globally. Fusarium wilt, caused by the soilborne fungal pathogen Fusarium oxysporum f. sp. vasinfectum (Fov), was estimated to cause a $21 million cotton yield loss in 2022. Historically, Alabama was an important producer of cotton in the Southeastern United States and was the first state in which Fusarium wilt on cotton was described. To assess the genetic diversity of Fov field isolates in Alabama, 118 field isolates were collected from six counties across the state from 2014 to 2016. Phylogenetic analysis using TEF1 and RPB2 placed the Fov field isolates into 18 haplotypes. Upon profiling the Tfo1 transposon insertion in the NAT gene, it was determined that no race 4 isolates were recovered in Alabama. Representatives of all field isolate haplotypes caused disease on Upland cotton variety Rowden in a hydroponic test tube assay. Two haplotype A isolates were the most aggressive isolates recovered, and haplotype A isolate TF1 was more aggressive than the race 4 isolate 89-1A on Upland cotton and had similar symptom severity on Pima cotton. Karyotype profiling indicted an abundance of small chromosomes characteristic of karyotypes that include accessory chromosomes, with considerable variability between isolates. Collectively, our study indicates that Fov isolates from Alabama are genetically diverse, which may have been promoted by its persistence in cotton fields.

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.

Genetic Diversity and Pathogenicity of the Fusarium Species Complex on Soybean in Serbia

Using morphological and cultural characteristics for identification, 36 Fusarium isolates were recovered from diseased roots, stems, and seeds of soybean from several localities throughout Vojvodina Province, Serbia. Based on molecular characterization, 12 Fusarium species were identified: F. acuminatum, F. avenaceum, F. commune, F. equiseti, F. graminearum, F. incarnatum, F. oxysporum, F. proliferatum, F. solani, F. sporotrichioides, F. subglutinans, and F. tricinctum. The elongation factor 1-α-based phylogeny grouped the isolates into 12 well-supported clades, but polymorphisms among sequences in some clades suggested the use of the species complex concept: (i) F. incarnatum-equiseti species complex (FIESC)-F. incarnatum and F. equiseti; (ii) F. oxysporum species complex (FOSC)-F. oxysporum; (iii) F. solani species complex (FSSC)-F. solani; and (iv) F. acuminatum/F. avenaceum/F. tricinctum species complex (FAATSC)-F. acuminatum, F. avenaceum, and F. tricinctum. Pathogenicity tests showed that the most aggressive species causing soybean seed rot were F. sporotrichioides, F. graminearum, FIESC, and F. avenaceum. Furthermore, F. subglutinans, FSSC, and F. proliferatum showed a high percentage of pathogenicity on soybean seeds (80 to 100%), whereas variability in pathogenicity occurred within isolates of F. tricinctum. FOSC, F. commune, and F. acuminatum had the lowest pathogenicity. To our knowledge, this is the first study of the characterization of Fusarium species on soybean in Serbia. This study provides valuable information about the composition of Fusarium species and pathogenicity that will be used in further research on soybean resistance to Fusarium-based diseases.

Genetic Diversity, Mycotoxin Profiles, and Population Structure of Fusarium spp. Associated with Fusarium Head Blight in Georgia, United States

Fusarium head blight (FHB) has become a limiting factor in soft red winter wheat production in the southeast United States. Recent epidemics have occurred in Georgia, but genetic information on the Fusarium species responsible for FHB is unknown. This study aimed to assess pathogen population structure and genetic diversity, trichothecene profiles, and representative pathogenicity of 196 Fusarium isolates collected from 44 wheat (n = 85) and 53 corn (n = 111) fields in Georgia. Phylogenetic analysis using the translation elongation factor 1-alpha (635 bp) and RNA polymerase second largest subunit (930 bp) sequence data resolved isolates into 185 haplotypes, which represented 12 Fusarium species grouped under five species complexes. F. graminearum with 15-acetyl-deoxynivalenol (15ADON) chemotype (75.6%) and F. incarnatum (57.7%) predominated in wheat and corn, respectively, with a surprisingly higher frequency of nivalenol (NIV) F. graminearum (21.8%). Using nine variable numbers of tandem repeat markers, 82 multilocus genotypes out of 86 F. graminearum isolates were identified and grouped into two genetic clusters, pop1fg (n = 29) and pop2fg (n = 32), as part of the North American populations (NA1 and NA2) but with no chemotype differentiation. F. graminearum populations in Georgia are mostly clonal and might have evolved through at least two introductions from the northeast United States and Canada and local adaptation to maintain high genetic diversity. Pathogenicity of F. graminearum isolates from wheat and corn had high FHB severity (>60%) in wheat, which depicted the risk they can pose towards future FHB outbreaks. Overall, this baseline study provided important information on Fusarium species diversity including F. graminearum associated with FHB in Georgia that will be useful to formulate integrated disease management incorporating improved host resistance and fungicide spray programs.

Pathogenicity, Host Resistance, and Genetic Diversity of Fusarium Species under Controlled Conditions from Soybean in Canada

Fusarium spp. are commonly associated with the root rot complex of soybean (Glycine max). Previous surveys identified six common Fusarium species from Manitoba, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum, and F. acuminatum. This study aimed to determine their pathogenicity, assess host resistance, and evaluate the genetic diversity of Fusarium spp. isolated from Canada. The pathogenicity of these species was tested on two soybean cultivars, 'Akras' (moderately resistant) and 'B150Y1' (susceptible), under greenhouse conditions. The aggressiveness of the fungal isolates varied, with root rot severities ranging from 1.5 to 3.3 on a 0-4 scale. Subsequently, the six species were used to screen a panel of 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits used in the pathogenicity study. Two cultivars, 'P15T46R2' and 'B150Y1', were consistently found to be tolerant to F. oxysporum, F. redolens, F. graminearum, and F. solani. To investigate the incidence and prevalence of Fusarium spp. in Canada, fungi were isolated from 106 soybean fields surveyed across Manitoba, Saskatchewan, Ontario, and Quebec. Eighty-three Fusarium isolates were evaluated based on morphology and with multiple PCR primers, and phylogenetic analyses indicated their diversity across the major soybean production regions of Canada. Overall, this study contributes valuable insights into host resistance and the pathogenicity and genetic diversity of Fusarium spp. in Canadian soybean fields.

Complete genome sequence of a novel partitivirus with a dsRNA3 segment, isolated from Fusarium commune strain CP-SX-3 causing strawberry root rot

A novel partitivirus, Fusarium commune partitivirus 1 (FcoPV1), was identified in Fusarium commune strain CP-SX-3 isolated from diseased roots of strawberry with symptoms of root rot. The complete genome of FcoPV1 comprises three double-stranded RNAs (dsRNAs): dsRNA1 (1,825 nt), dsRNA2 (1,592 nt), and dsRNA3 (1,421 nt). dsRNA1 contains a single open reading frame (ORF1) encoding an RNA-dependent RNA polymerase (RdRp), and dsRNA2 contains a single ORF (ORF2) encoding a coat protein (CP). dsRNA3 is a possible satellite RNA that does not appear to encode a known protein. BLASTp analysis revealed that RdRp (86.59%) and CP (74.13%) encoded by the two ORFs (ORF1 and ORF2) had the highest sequence similarity to their counterparts in Fusarium equiseti partitivirus 1 (FePV1). Phylogenetic analysis based on the complete amino acid sequence of RdRp suggested that FcoPV1 should be considered a member of a new species in the proposed genus "Zetapartitivirus" within the family Partitiviridae. To the best of our knowledge, this is the first report of a zetapartitivirus infecting phytopathogenic F. commune.

Fusarium species associated with citrus blackfly (Aleurocanthus woglumi) from an agroecological polyculture in Brazil, including an augmented description of F. volatile

The objectives of this study were to report Fusarium species associated with Aleurocanthus woglumi (Hemiptera: Aleyrodidae) collected from citrus leaves from an agroecological polyculture in Brazil, assess sexual reproductive mode of the species with unknown sexual stages, and provide an augmented description of F. volatile, for which we discovered a sexual stage. Nineteen Fusarium isolates were recovered from A. woglumi. These fungi belong to three species complexes, i.e., the F. chlamydosporum species complex (FCSC), the F. fujikuroi species complex (FFSC), and the F. incarnatum-equiseti species complex (FIESC). Based on multilocus phylogenetic analyses, the species were identified as F. annulatum, F. chlamydosporum, F. pernambucanum, F. sulawesiense, F. verticillioides, and F. volatile. Our results suggest that three species whose sexual stages are unknown (F. chlamydosporum, F. sulawesiense, and F. volatile) are also heterothallic. Intraspecific crosses of F. sulawesiense and F. volatile produced protoperithecia, whereas 66.7% of F. volatile crosses produced fertile perithecia. We provide an augmented description of the latter species to include characteristics of its sexual morph and those observed in the asexual morph that had not yet been described for the species. This study highlights the potential of researching insect-associated fungi to increase knowledge about the diversity, taxonomy, and versatility of Fusarium in ecosystems.

Molecular Identification and Characterization of Fusarium Associated with Walnut Branch Blight Disease in China

In October 2020, samples of walnut branch blight were collected from Longnan. Pathogens were isolated and identified based on morphological and molecular features, and their characteristics were analyzed by pathogenicity. Pathogenicity testing revealed that seven strains (LN-1, LN-3, LN-6, LN-19, LN-27, QY3-1, and QY9-1) induced symptoms of walnut branch blight that were consistent with those observed in the field after inoculation. Furthermore, some Fusarium-type conidia and spherical chlamydospores were visible indicating that they were Fusarium spp. A molecular characterization including sequence and phylogenetic analysis of the ITS, TEF-1α, βTUB, Fu, and LSU gene regions revealed that LN-1 and LN-19 belonged to F. avenaceum, LN-3 and LN-6 to F. acuminatum, LN-27 to F. sporotrichioides, and QY3-1 and QY9-1 to F. tricinctum. This is the first time that F. acuminatum-, F. sporotrichioides-, and F. tricinctum-caused walnut branch blight has been reported in China.

Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus

Fusarium species are important cereal pathogens that cause severe production losses to major cereal crops such as maize, rice, and wheat. However, the causal agents of Fusarium diseases on cereals have not been well documented because of the difficulty in species identification and the debates surrounding generic and species concepts. In this study, we used a citizen science initiative to investigate diseased cereal crops (maize, rice, wheat) from 250 locations, covering the major cereal-growing regions in China. A total of 2 020 Fusarium strains were isolated from 315 diseased samples. Employing multi-locus phylogeny and morphological features, the above strains were identified to 43 species, including eight novel species that are described in this paper. A world checklist of cereal-associated Fusarium species is provided, with 39 and 52 new records updated for the world and China, respectively. Notably, 56 % of samples collected in this study were observed to have co-infections of more than one Fusarium species, and the detailed associations are discussed. Following Koch's postulates, 18 species were first confirmed as pathogens of maize stalk rot in this study. Furthermore, a high-confidence species tree was constructed in this study based on 1 001 homologous loci of 228 assembled genomes (40 genomes were sequenced and provided in this study), which supported the "narrow" generic concept of Fusarium (= Gibberella). This study represents one of the most comprehensive surveys of cereal Fusarium diseases to date. It significantly improves our understanding of the global diversity and distribution of cereal-associated Fusarium species, as well as largely clarifies the phylogenetic relationships within the genus. Taxonomic novelties: New species: Fusarium erosum S.L. Han, M.M. Wang & L. Cai, Fusarium fecundum S.L. Han, M.M. Wang & L. Cai, Fusarium jinanense S.L. Han, M.M. Wang & L. Cai, Fusarium mianyangense S.L. Han, M.M. Wang & L. Cai, Fusarium nothincarnatum S.L. Han, M.M. Wang & L. Cai, Fusarium planum S.L. Han, M.M. Wang & L. Cai, Fusarium sanyaense S.L. Han, M.M. Wang & L. Cai, Fusarium weifangense S.L. Han, M.M. Wang & L. Cai. Citation: Han SL, Wang MM, Ma ZY, Raza M, Zhao P, Liang JM, Gao M, Li YJ, Wang JW, Hu DM, Cai L (2023). Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus. Studies in Mycology 104: 87-148. doi: 10.3114/sim.2022.104.02.

Fusarium diversity from the Golden Gate Highlands National Park

Members from the genus Fusarium can infect a broad range of plants and threaten agricultural and horticultural production. Studies on the diversity of Fusarium occurring in natural ecosystems have received less attention than the better known phytopathogenic members of the genus. This study identified Fusarium species from soils with low anthropogenic disturbance found in the Golden Gate Highlands National Park (GGHNP), a part of the Drakensberg system in South Africa. Selective techniques were implemented to obtain 257 individual isolates from the selected soil samples for which the translation elongation factor 1α (tef-1α) gene region was sequenced and compared against the Fusarium MLST and FUSARIUM-ID databases. Phylogenetic analyses, based on maximum likelihood and Bayesian inference, were used to determine species diversity in relation to reference isolates. Species level identifications were made within three of the seven species complexes and identified F. brachygibbosum, F. sporotrichioides, F. andiyazi, and F. gaditjirri based on the FUSARIUM-ID database, with F. transvaalense and F. lyarnte identified against the Fusarium MLST database. This indicated highly diverse populations of Fusarium from soils with low anthropogenic disturbance from the Afromontane grassland region found in mountain ranges.

A Repertoire of Clinical Non-Dermatophytes Moulds

Humans are constantly exposed to micromycetes, especially filamentous fungi that are ubiquitous in the environment. In the presence of risk factors, mostly related to an alteration of immunity, the non-dermatophyte fungi can then become opportunistic pathogens, causing superficial, deep or disseminated infections. With new molecular tools applied to medical mycology and revisions in taxonomy, the number of fungi described in humans is rising. Some rare species are emerging, and others more frequent are increasing. The aim of this review is to (i) inventory the filamentous fungi found in humans and (ii) provide details on the anatomical sites where they have been identified and the semiology of infections. Among the 239,890 fungi taxa and corresponding synonyms, if any, retrieved from the Mycobank and NCBI Taxonomy databases, we were able to identify 565 moulds in humans. These filamentous fungi were identified in one or more anatomical sites. From a clinical point of view, this review allows us to realize that some uncommon fungi isolated in non-sterile sites may be involved in invasive infections. It may present a first step in the understanding of the pathogenicity of filamentous fungi and the interpretation of the results obtained with the new molecular diagnostic tools.

Identification and Characterization of Fusarium Species Causing Watermelon Fruit Rot in Northern Thailand

Fruit rot caused by phytopathogenic fungi is one of the major diseases affecting watermelons (Citrullus lanatus) around the world, which can result in unmarketable fruits and significant economic losses. Fruit rot was observed on watermelons throughout the postharvest storage periods in Phayao Province, northern Thailand in 2022. For the present study, a total of ten fungal isolates were isolated from the rot lesions of watermelons. All obtained fungal isolates were then characterized in terms of their pathogenicity. The results indicated that only four fungal isolates caused rot disease with similar symptoms during the postharvest storage period. Based on their morphological characteristics, these four fungal isolates were identified as belonging to the genus Fusarium. Using multi-gene phylogenetic analyses with a combination of the translation elongation factor 1-alpha (tef-1), calmodulin (cam), and RNA polymerase second largest subunit (rpb2) genes, the fungal isolates were subsequently identified as Fusarium compactum and F. paranaense. Taken together, the results of this study indicate that F. compactum and F. paranaense cause fruit rot disease in watermelons. To the best of our knowledge, this is the first study to report F. compactum and F. paranaense as novel pathogens of watermelon fruit rot both in Thailand and elsewhere in the world.

First report on molecular identification of Fusarium species causing fruit rot of mandarin ( Citrus reticulata) in Bangladesh

Background: Fusarium rot is a newly introduced, devastating disease of citrus fruits. The current investigation was undertaken to characterize the microbes responsible for fruit rot in Citrus reticulata. Methods: Pathogens were isolated from infected citrus fruits using morphological and molecular approaches. For confirmation of the isolated fungi, polymerase chain reaction (PCR) amplification and internal transcribed spacer gene sequencing techniques were used. Results: The isolated fungus was grown on potato dextrose agar for three days and it produced clamydospores, hyphae and macroconidia. PCR amplification of isolated fungal DNA gave a 650 bp product. The sequence obtained from isolated fungi had 99.42% similarity with the reference Fusarium concentricum sequence in NCBI GenBank. The obtained sequence was deposited in GenBank (Accession No. MT856371). Two isolates showed virulence capability on fresh guava, sweet orange and tomato fruits, which confirmed species identification and Koch's postulates. Artificially inoculated fungal species grown on tested fruits showed typical Fusarium species symptoms. Conclusions: Outcomes of the present study are beneficial for the detection of this detrimental disease in postharvest Citrus reticulata fruits. Further research is needed for the control of this economically important disease. This is the first study of fruit rot in Citrus reticulata caused by Fusarium in Bangladesh.

First report on molecular identification of Fusarium species causing fruit rot of mandarin ( Citrus reticulata) in Bangladesh

Background: Fusarium rot is a newly introduced, devastating disease of citrus fruits. The current investigation was undertaken to characterize the microbes responsible for fruit rot in Citrus reticulata. Methods: Pathogens were isolated from infected citrus fruits using morphological and molecular approaches. For confirmation of the isolated fungi, polymerase chain reaction (PCR) amplification and internal transcribed spacer gene sequencing techniques were used. Results: The isolated fungus was grown on potato dextrose agar for three days and it produced clamydospores, hyphae and macroconidia. PCR amplification of isolated fungal DNA gave a 650 bp product. The sequence obtained from isolated fungi had 99.42% similarity with the reference Fusarium concentricum sequence in NCBI GenBank. The obtained sequence was deposited in GenBank (Accession No. MT856371). Two isolates showed virulence capability on fresh guava, sweet orange and tomato fruits, which confirmed species identification and Koch's postulates. Artificially inoculated fungal species grown on tested fruits showed typical Fusarium species symptoms. Conclusions: Outcomes of the present study are beneficial for the detection of this detrimental disease in postharvest Citrus reticulata fruits. Further research is needed for the control of this economically important disease. This is the first study of fruit rot in Citrus reticulata caused by Fusarium in Bangladesh.

Isolation, molecular characterization and first report of Dothiorella gregaria associated with fruit rot of walnuts of Jammu and Kashmir, India

Walnuts are known for their high levels of antioxidants, which are linked to various health benefits. However, challenges related to distribution and storage, as well as the risk of fungal infections, can affect the quality of walnut kernels. Fungal pathogens from the Botryosphaeriaceae family, including Dothiorella species and Diplodia species, can damage fruit and reduce its antioxidant content. To comprehend the cause of fruit rot in walnuts, Dothiorella gregaria isolates were studied using polyphasic methods, including multiple gene sequences and morphological identification, as well as analysis of polyphenol content and pathogenicity. The walnuts kernels purchased from market places of Jammu and Kashmir (J&K), India were observed to be affected by Dothiorella gregaria species causing the quality detoriation and decrease in polyphenol content thus undeniably with decreased antioxidant properties. D. gregaria Infected walnut kernels were having some brown and black spots and some were having white mycelial growth and however, most samples were asymptomatic. Pathogenicity testing revealed that the pathogen was able to develop all the symptoms under experimental conditions and the reisolated pathogen was morphologically similar to D. gregaria. The samples infected with this pathogen showed considerable decrease in polyphenol content, 10.9 ± 2.66 mgGAE/g (mean ± standard deviation) thus decreased antioxidant quality as compared to the samples which showed zero incidence of this pathogen, 52.50 ± 4.27 mgGAE/g (mean ± standard deviation). Furthermore, the pathogen was studied using polyphasic approach involving morphological, molecular and phylogenetic analysis. Combined nucleotide dataset of nuclear ribosomal ITS and tef1-α revealed that Dothiorella gregaria (NY6) formed a clade with Dothiorlla iberica (MAEC33), Dothiorella sarmentorium (MAEC28) and Dothiorella iberica (CAA905) strains with 83% bootstrap support. Besides, we observed six nucleotide changes, four were insertions or deletions and two were substitutions in the 502-bp region of the ITS rRNA gene when we compared our isolate to the most equivalent sequences submitted to NCBI GenBank. This is the first report of Dothiorella gregaria affecting walnuts purchased from various markets in J&K, India, causing fruit rot in walnuts after harvest. Given that local farmers store and export walnuts, it could pose an emerging threat to their livelihood. Thus, creating post-harvesting interventions for D. gregaria and knowing more about the fruit rot in walnuts can be benefited from morphological and molecular identification using several gene loci, genetic variability in the ITS rRNA gene, and total phenol analysis.

Multilocus molecular phylogenetic-led discovery and formal recognition of four novel root-colonizing Fusarium species from northern Kazakhstan and the phylogenetically divergent Fusarium steppicola lineage

In this study, DNA sequence data were used to characterize 290 Fusarium strains isolated during a survey of root-colonizing endophytic fungi of agricultural and nonagricultural plants in northern Kazakhstan. The Fusarium collection was screened for species identity using partial translation elongation factor 1-α (TEF1) gene sequences. Altogether, 16 different Fusarium species were identified, including eight known and four novel species, as well as the discovery of the phylogenetically divergent F. steppicola lineage. Isolates of the four putatively novel fusaria were further analyzed phylogenetically with a multilocus data set comprising partial sequences of TEF1, RNA polymerase II largest (RPB1) and second-largest (RPB2) subunits, and calmodulin (CaM) to assess their genealogical exclusivity. Based on the molecular phylogenetic and comprehensive morphological analyses, four new species are formally described herein: F. campestre, F. kazakhstanicum, F. rhizicola, and F. steppicola.

A Practical Workflow for the Identification of Aspergillus, Fusarium, Mucorales by MALDI-TOF MS: Database, Medium, and Incubation Optimization

There is an increasing body of literature on the utility of MALDI-TOF MS in the identification of filamentous fungi. However, the process still lacks standardization. In this study, we attempted to establish a practical workflow for the identification of three clinically important molds: Aspergillus, Fusarium, and Mucorales using MALDI-TOF MS. We evaluated the performance of Bruker Filamentous Fungi database v3.0 for the identification of these fungi, highlighting when there would be a benefit of using an additional database, the MSI-2 for further identification. We also examined two other variables, namely, medium effect and incubation time on the accuracy of fungal identification. The Bruker database achieved correct species level identification in 85.7% of Aspergillus and 90% of Mucorales, and correct species-complex level in 94.4% of Fusarium. Analysis of spectra using the MSI-2 database would also offer additional value for species identification of Aspergillus species, especially when suspecting species with known identification limits within the Bruker database. This issue would only be of importance in selected cases where species-level identification would impact therapeutic options. Id-Fungi plates (IDFP) had almost equivalent performance to Sabouraud dextrose agar (SDA) for species-level identification of isolates and enabled an easier harvest of the isolates with occasional faster identification. Our study showed accurate identification at 24 h for Fusarium and Mucorales species, but not for Aspergillus species, which generally required 48 h.

Fusarium diversity associated with the Sorghum-Striga interaction in Ethiopia

Sorghum production is seriously threatened by the root parasitic weeds (RPWs) Striga hermonthica and Striga asiatica in sub-Saharan Africa. Research has shown that Striga control depends on eliminating its seed reserves in soil. Several species of the genus Fusarium (Nectriaceae, Hypocreales), which have been isolated from diseased Striga plants have proven to be highly pathogenic to all developmental stages of these RPWs. In the present study 439 isolates of Fusarium spp. were found associated with soils from Sorghum growing fields, Sorghum rhizosphere, or as endophytes with Sorghum roots and seeds, or as endophytes of Striga stems and seeds. Based on multi-locus phylogenies of combinations of CaM, tef1, rpb1 and rpb2 alignments, and morphological characteristics, 42 species were identified, including three species that are newly described, namely F. extenuatum and F. tangerinum from Sorghum soils, and F. pentaseptatum from seed of Striga hermonthica. Using a previously published AFLP-derived marker that is specific to detect isolates of F. oxysporum f.sp. strigae, an effective soil-borne biocontrol agent against Striga, we also detected the gene in several other Fusarium species. As these isolates were all associated with the Striga/Sorghum pathosystem, the possibility of horizontal gene transfer among these fusaria will be of interest to further investigate in future. Citation: Lombard L, van Doorn R, Groenewald JZ, Tessema T, Kuramae EE, Etolo DW, Raaijmakers JM, Crous PW (2022). Fusarium diversity associated with the Sorghum-Striga interaction in Ethiopia. Fungal Systematics and Evolution 10: 177-215. doi: 10.3114/fuse.2022.10.08.

Fusarium Species Associated with Maize Leaf Blight in Heilongjiang Province, China

Fusarium spp. are among the most important plant pathogens in the world. A survey on maize leaf blight was carried out in Heilongjiang province from 2019 to 2021. Based on morphological characteristics and a phylogenetic analysis on translation elongation factor (tef1) and second-largest subunit of RNA polymerase II (rpb2) genes, 146 Fusarium isolates were obtained and grouped into 14 Fusarium species, including F. ipomoeae (20.5%), F. compactum (17.1%), F. sporotrichioides (9.59%), F. graminearum (9.59%), F. citri (8.9%), F. asiaticum (6.85%), F. verticillioides (6.85%), F. acuminatum (5.48%), F. glycines (5.48%), F. temperatum (2.74%), F. armeniacum (2.74%), Fusarium sp. (2.05%), F. flagelliforme (1.4%), and F. annulatum (0.68%). The Fusarium incarnatum-equiseti species complex (FIESC, including F. ipomoeae, F. compactum, F. citri, and F. flagelliforme) was the most prevalent, indicating an evolving occurrence of the Fusarium species causing maize leaf blight. The typical symptoms observed on the maize leaves were oval to long strip lesions, with a gray to dark gray or brownish red coloration in the center and a chlorotic area at the edges. Based on the tef1 gene, seven haplotypes of FIESC were identified in Heilongjiang province, suggesting a population expansion. This is the first report of F. ipomoeae, F. compactum, F. flagelliforme, F. citri, F. sporotrichioides, F. graminearum, F. asiaticum, F. acuminatum, F. glycines, F. temperatum, F. armeniacum, Fusarium sp., and F. annulatum causing maize leaf blight in Heilongjiang province, China. The current research is informative for managing disease, exploring the phylogenetic relationship among Fusarium species, and clarifying the diversity of Fusarium species associated with maize leaf blight.

Morphology, Molecular Identification, and Pathogenicity of Two Novel Fusarium Species Associated with Postharvest Fruit Rot of Cucurbits in Northern Thailand

Fruit rot of cucurbits caused by several pathogenic fungi has become an important postharvest disease worldwide. In 2022, fruit rot on watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) was observed during the postharvest storage phase in the Chiang Mai and Phitsanulok Provinces of northern Thailand. These diseases can lead to significant economic losses. This present study was conducted to isolate the causal agent of fungi in lesions of fruit rot. A total of four fungal isolates were obtained, of which two isolates (SDBR-CMU422 and SDBR-CMU423) were obtained from rot lesions of watermelons, while the remaining isolates (SDBR-CMU424 and SDBR-CMU425) were obtained from rot lesions of muskmelons. All fungal isolates were identified using both morphological characteristics and molecular analyses. Morphologically, all isolated fungal isolates were classified into the genus Fusarium. Multi-gene phylogenetic analyses of a combination of the translation elongation factor 1-alpha (tef-1), calmodulin (cam), and RNA polymerase second largest subunit (rpb2) genes reveled that four fungal isolates belonged to the Fusarium incarnatum-equiseti species complex and were distinct from all other known species. Thus, we have described them as two new species, namely F. citrullicola (SDBR-CMU422 and SDBR-CMU423) and F. melonis (SDBR-CMU424 and SDBR-CMU425). A full description, illustrations, and a phylogenetic tree indicating the position of both new species have been provided. Moreover, pathogenicity tests were subsequently performed and the results showed that F. citrullicola and F. melonis caused symptoms of fruit rot on inoculated watermelon and muskmelon fruits, respectively. Notably, this outcome was indicative of the symptoms that appeared during the postharvest storage phase. To our knowledge, two new pathogenic fungi, F. citrullicola and F. melonis, are new causal agents of watermelon and muskmelon fruit rot, respectively. Importantly, these findings provide valuable information for the development of effective strategies for the monitoring and prevention of these diseases.

The distribution and type B trichothecene chemotype of Fusarium species associated with head blight of wheat in South Africa during 2008 and 2009

Fusarium head blight (FHB) of wheat occurs commonly in irrigation regions of South Africa and less frequently in dryland regions. Previous surveys of Fusarium species causing FHB identified isolates using morphological characters only. This study reports on a comprehensive characterisation of FHB pathogens conducted in 2008 and 2009. Symptomatic wheat heads were collected from the Northern Cape, KwaZulu-Natal (KZN), Bushveld and eastern Free State (irrigation regions), and from one field in the Western Cape (dryland region). Fusarium isolates were identified with species-specific primers or analysis of partial EF-1α sequences. A representative subset of isolates was characterized morphologically. In total, 1047 Fusarium isolates were collected, comprising 24 species from seven broad species complexes. The F. sambucinum (FSAMSC) and F. incarnatum-equiseti species complexes (FIESC) were most common (83.5% and 13.3% of isolates, respectively). The F. chlamydosporum (FCSC), F. fujikuroi (FFSC), F. oxysporum (FOSC), F. solani (FSSC), and F. tricinctum species complexes (FTSC) were also observed. Within the FSAMSC, 90.7% of isolates belonged to the F. graminearum species complex (FGSC), accounting for 75.7% of isolates. The FGSC was the dominant Fusaria in all four irrigation regions. F. pseudograminearum dominated at the dryland field in the Western Cape. The Northern Cape had the highest species diversity (16 Fusarium species from all seven species complexes). The type B trichothecene chemotype of FGSC and related species was inferred with PCR. Chemotype diversity was limited (15-ADON = 90.1%) and highly structured in relation to species differences. These results expand the known species diversity associated with FHB in South Africa and include first reports of F. acuminatum, F. armeniacum, F. avenaceum, F. temperatum, and F. pseudograminearum from wheat heads in South Africa, and of F. brachygibbosum, F. lunulosporum and F. transvaalense from wheat globally. Potentially novel species were identified within the FCSC, FFSC, FOSC, FSAMSC, FIESC and FTSC.

Morphology, Phenotype, and Molecular Identification of Clinical and Environmental Fusarium solani Species Complex Isolates from Malaysia

Fusarium infections in humans (fusariosis) and in economically important plants involve species of several Fusarium species complexes. Species of the Fusarium solani species complex (FSSC) are the most frequent cause of human fusariosis. The FSSC comprises more than 60 closely related species that can be separated into three major clades by multi-locus sequence typing (MLST) using translation elongation factor 1-alpha (TEF1-α) and RNA polymerase II (RPB2) DNA sequences. The MLST nomenclature for clade 3 of the FSSC assigns numbers to species types (e.g., FSSC 2) and lowercase letters to identify unique haplotypes. The aim of this study was to analyse the genotypic and phenotypic characteristics of 15 environmental and 15 clinical FSSC isolates from Malaysia. MLST was used for the genotypic characterisation of FSSC isolates from various locations within Malaysia, which was complemented by their morphological characterisation on potato dextrose and carnation leaf agar. MLST identified eight different FSSC species: thirteen Fusarium keratoplasticum (i.e., FSSC 2), six Fusarium suttonianum (FSSC 20), five Fusarium falciforme (FSSC 3+4), two Fusarium cyanescens (FSSC 27), and one each of Fusarium petroliphilum (FSSC 1), Fusarium waltergamsii (FSSC 7), Fusarium sp. (FSSC 12), and Fusarium striatum (FSSC 21). Consistent with previous reports from Malaysia, most (11 of 15) clinical FSSC isolates were F. keratoplasticum and the majority (9 of 15) of environmental isolates were F. suttonianum (5) or F. falciforme (4) strains. The taxonomic relationships of the isolates were resolved phylogenetically. The eight Fusarium species also showed distinct morphological characteristics, but these were less clearly defined and reached across species boundaries. Although TEF1-α and RPB2 sequences were sufficient for the species identification of most FSSC isolates, a more precise MLST scheme needs to be established to reliably assign individual isolates of the species-rich FSSC to their geographically-, epidemiologically-, and host-associated sub-lineages.

Prevalence, genetic diversity and antifungal susceptibility profiles of F. fujikuroi, F. solani, and Fusarium incarnatum-equiseti species complexes from onychomycosis in North of Iran

Onychomycosis, a nail fungal infection, is normally caused by dermatophytes. However, yeasts and non-dermatophyte molds (NDM) are among pathogens that cause nail disease. Regarding, this study aimed to describe the molecular epidemiology of Fusarium onychomycosis in the North of Iran. 257 nail samples collected from the patients clinically suspected of onychomycosis were subjected to direct microscopy, calcofluor white staining, and culture. Fusarium isolates were identified at a species level through determination of multi-locus sequences for internal transcribed spacer and translation elongation factor 1 alpha. Based on the findings, Fusarium species were isolated from onychomycosis patients (n=27). According to a previous partial genes analysis, the species in the resent study belonged to the members of F. fujikuroi species complex (n=14), Fusarium incarnatum-equiseti species complex (n=1) and F. solani species complex (n=12). In rhis study, F. proliferatum was the dominant Fusarium species collected from the samples. The correct identification of Fusarium species is essential regarding the increased prevalence of Fusarium onychomycosis and the inherent resistance of these agents to a wide spectrum of antifungals. The obtained results indicated variation in the epidemiology of Fusarium species isolated from onychomycosis. Moreover, the minimum inhibitory concentration (MIC) of luliconazole and lanoconazole was in the range of 0.001-1 μg/mL, with the geometric mean of MICs obtained at 0.0103 and 0.0343 μg/mL against Fusarium species, respectively. These findings can increase researchers' knowledge regarding diversity of species, distribution of onychomycosis, and the choice of a proper treatment.

Multigene Phylogeny, Beauvericin Production and Bioactive Potential of Fusarium Strains Isolated in India

The taxonomy of the genus Fusarium has been in a flux because of ambiguous circumscription of species-level identification based on morphotaxonomic criteria. In this study, multigene phylogeny was conducted to resolve the evolutionary relationships of 88 Indian Fusarium isolates based on the internal transcribed spacer region, 28S large subunit, translation elongation factor 1-alpha, RNA polymerase second largest subunit, beta-tubulin and calmodulin gene regions. Fusarium species are well known to produce metabolites such as beauvericin (BEA) and enniatins. These identified isolates were subjected to fermentation in Fusarium-defined media for BEA production and tested using TLC, HPLC and HRMS. Among 88 isolates studied, 50 were capable of producing BEA, which varied from 0.01 to 15.82 mg/g of biomass. Fusarium tardicrescens NFCCI 5201 showed maximum BEA production (15.82 mg/g of biomass). The extract of F. tardicrescens NFCCI 5201 showed promising antibacterial activity against Staphylococcus aureusMLS16 MTCC 2940 and Micrococcus luteus MTCC 2470 with MIC of 62.5 and 15.63 µg/mL, respectively. Similarly, the F. tardicrescens NFCCI 5201 extract in potato dextrose agar (40 µg/mL) exhibited antifungal activity in the food poison technique against plant pathogenic and other fungi, Rhizoctonia solani NFCCI 4327, Sclerotium rolfsii NFCCI 4263, Geotrichum candidum NFCCI 3744 and Pythium sp. NFCCI 3482, showing % inhibition of 84.31, 49.76, 38.22 and 35.13, respectively. The antibiotic effect was found to synergize when Fusarium extract and amphotericin B (20 µg/mL each in potato dextrose agar) were used in combination against Rhizopus sp. NFCCI 2108, Sclerotium rolfsii NFCCI 4263, Bipolaris sorokiniana NFCCI 4690 and Absidia sp. NFCCI 2716, showing % inhibition of 50.35, 79.37, 48.07 and 76.72, respectively. The extract also showed satisfactory dose-dependent DPPH radical scavenging activity with an IC50 value of 0.675 mg/mL. This study reveals the correct identity of the Indian Fusarium isolates based on multigene phylogeny and also throws light on BEA production potential, suggesting their possible applicability in the medicine, agriculture and industry.

DNA Sequence-Based Identification of Fusarium: A Work in Progress

Accurate species-level identification of an etiological agent is crucial for disease diagnosis and management because knowing the agent's identity connects it with what is known about its host range, geographic distribution, and toxin production potential. This is particularly true in publishing peer-reviewed disease reports, where imprecise and/or incorrect identifications weaken the public knowledge base. This can be a daunting task for phytopathologists and other applied biologists that need to identify Fusarium in particular, because published and ongoing multilocus molecular systematic studies have highlighted several confounding issues. Paramount among these are: (i) this agriculturally and clinically important genus is currently estimated to comprise more than 400 phylogenetically distinct species (i.e., phylospecies), with more than 80% of these discovered within the past 25 years; (ii) approximately one-third of the phylospecies have not been formally described; (iii) morphology alone is inadequate to distinguish most of these species from one another; and (iv) the current rapid discovery of novel fusaria from pathogen surveys and accompanying impact on the taxonomic landscape is expected to continue well into the foreseeable future. To address the critical need for accurate pathogen identification, our research groups are focused on populating two web-accessible databases (FUSARIUM-ID v.3.0 and the nonredundant National Center for Biotechnology Information nucleotide collection that includes GenBank) with portions of three phylogenetically informative genes (i.e., TEF1, RPB1, and RPB2) that resolve at or near the species level in every Fusarium species. The objectives of this Special Report, and its companion in this issue (Torres-Cruz et al. 2022), are to provide a progress report on our efforts to populate these databases and to outline a set of best practices for DNA sequence-based identification of fusaria.

First Report of Damping off and Seedling Rot of Hemp (Cannabis sativa L.) caused by Fusarium solani (Mart.) Sacc. in North Dakota, USA

Hemp (Cannabis sativa L.) is grown for medicinal and industrial uses. Symptomatic hemp (Mountain Mango) seedlings were received from a grower's greenhouse in Towner County (48.7486° N, 99.2761° W), North Dakota (ND), USA in July 2020. Seedlings had brown to blackish root tips, thread-like hypocotyl rot and seedling collapse, with about 8 to 10% disease incidence. Roots were surface disinfested in 1% sodium hypochlorite for 1 min, rinsed thrice with sterile distilled water, and blotted dry. About 1-cm sectioned root tips were plated on water agar (WA) and acidified potato dextrose agar (PDA, pH: 4.8) media and incubated under fluorescent light with a 12-h photoperiod at 25° C. After 7 days, single spores were isolated and sub-cultured on PDA and carnation leaf agar for morphological observations (Dhingra and Sinclair, 1995). Colonies had uniform appearances and produced white, thick and floccose mycelium. Conidiophores produced from lateral hyphae were simple to branched. Phialides were slender, smooth, hyaline and septate. Macro-conidia were 12.5 to 30.2 x 2.2 to 3.6 µm, septate (3-5), thick walled, hyaline and moderately curved shaped. Micro-conidia were oval to ellipsoid, smooth walled, no septa and measured 3.4 to 8.8 μm and 1.3 to 4.3 μm. Chlamydospores were round shaped, thick-walled, and produced singly or in pairs. Based on morphological characteristics, isolates were identified as Fusarium solani (Mart.) (Carbone and Kohn 1999; Leslie and Summerell 2006). For molecular identification, genomic DNA of three representative fungal isolates were extracted using DNeasy Plant Mini Kit (Qiagen, Hilden, Germany). PCR was done using both the primers (EF1/EF2) of the translation elongation factor (TEF-1α) and primers 5F2/7cR and 7cF/11aR of the RNA polymerase II (RPB 2) for Fusarium species (O'Donnell et al. 2009 and 2010). All isolates had identical PCR product sequences for the respective primer sets. The DNA sequences were deposited to NCBI GenBank with accession No. OK880264 (TEF-1α), OK880266 (RBP 5F2/7cR), and OK880265 (RBP 7cF/11aR). The NCBI Megablast search of the OK880264, OK880266, and OK880265 showed 100% similarity with respective homologue sequences from F. solani species complex (GU170628, KC808344, and EU329608). Similar results were obtained by BLASTN search in the FUSARIUM ID database (Geiser et al. 2004). For pathogenicity testing, 200 µl conidial suspension (1 x 106 conidia/ml) was pipetted, without wounding roots, onto the soil around the base of four plants individually potted in peat mix (Sunshine mix 1, Sun Gro Horticulture Ltd.; Alberta, Canada) and maintained in the greenhouse with 12 h photoperiod and temperature of 23 ± 2°C (Argus Control Systems Ltd.; British Columbia, Canada). Four plants inoculated with distilled water served as control. The test was conducted twice. At 10 days post inoculation (dpi), yellowing of leaves and damping off were observed in all inoculated plants. Re-isolated fungi from infected plant samples were morphologically identical to the isolate used for root inoculation. F. solani has been reported to cause damping off and root rot in several states in the U.S., Canada and Italy (Gauthier et al. 2019; Iriarte et al. 2021; Sorrentino et al. 2019). This is the first report of F. solani causing seedling damping off and root rot on hemp in ND. Hemp acreage has decreased in ND because of diseases (Buetow et al. 2020). Information on identification and management of diseases affecting hemp will be useful to producers.

First Report of Fusarium Sheath Rot of Rice Caused by Fusarium incarnatum-equiseti Species Complex in the United States

Fungal diseases, including sheath rot (Sarocladium oryzae), cause significant losses of yield and milling quality of rice (Oryza sativa). In August 2021, symptoms like sheath rot were observed on 20% of rice plants (cv. Presidio) in 1-hectare field in Eagle Lake, Texas. Initial lesions occurred on the upper flag leaf sheaths and were oblong or irregular oval, with gray to light brown centers, and a dark reddish-brown diffuse margin. Lesions enlarged, coalesced, and covered a large area of the sheath. Infection led to panicle rot with kernels turning dark brown. Unlike sheath rot, sheath infection also led to inside culm infection with irregular dark brown lesions. Infected tissue pieces were sterilized with 1% NaOCl for 2 min, followed by 75% ethanol for 30 s, washed in sterile H2O three times, air dried and incubated on PDA at 27℃. Fungal isolates were obtained from 15 diseased plant samples and their singled-spored fungal colonies were whitish, loosely floccose and produced light yellow pigmentation. On carnation leaf agar, macroconidia were slightly curved and tapered at the ends, with 3 to 5 septa, and measured 17.5 to 34.3 × 3.1 to 5.0 µm. Microconidia were ovoid, usually with 0 to 1 septum and were 4.0 to 15.5 × 2.5 to 4.5 µm. Spherical shaped chlamydospores were produced in chain. These morphological characteristics were consistent to those described for Fusarium incarnatum-equiseti species complex (O'Donnell et al. 2009), including F. incarnatum (Wang et al. 2021) and F. equiseti (Avila et al. 2019). For molecular identification, DNA of a representative isolate was extracted and ITS, LSU, and EF1 of the fungus were amplified using the primers of ITS1/ITS4 (Wang et al. 2014), D1/D2 domain region of LSU (Fell et al. 2000), and EF1 (Wang et al. 2014), respectively, and sequenced. The ITS sequence (OL344049) was 99.61% identical to F. incarnatum-equiseti species complex (FD_01692) in Fusarium-ID database and 99.61% identical to F. equiseti (LC514690, KY523100, MW016539) and F. incarnatum (MH979697) in NCBI database. The LSU sequence (OK559512) was 98.77% similar to F. equiseti (MN877913, MN368509) and F. incarnatum (MH877332, MH877326); the EF1 sequence (OK570044) was 99.27% similar to F. equiseti (MK278902) in NCBI database. A phylogenetic analysis based on the concatenated nucleotide sequences grouped this isolate in the F. incarnatum-equiseti species complex clade at 100% bootstrap support. To evaluate pathogenicity, a conidial suspension of 1 x 106 conidia/ml or sterilized water (the controls) was injected into the sheaths and young panicles of three rice plants (cv. Presidio) at boot. Treated plants were maintained in a greenhouse at 25 to 30℃. After 3 weeks, typical symptoms, like those observed in the field, developed on the inoculated plants but not on the controls. The same fungus was consistently re-isolated from the diseased plants. To our knowledge, this is the first report of Fusarium sheath rot caused by F. incarnatum-equiseti species complex in rice in the U. S. F. incarnatum-equiseti species complex has been reported to be associated with panicle infection in wild rice (O. latifolia) in Brazil (Tralamazza et al. 2021). F. incarnatum has also been reported to cause panicle rot in China (Wang et al. 2021). F. proliferatum has been reported to cause Fusarium sheath rot in India (Prabhukarthikeyan et al. 2021) and the U. S. (Cartwright et al. 1995). This research demonstrates the potential of different pathogens being involved in causing sheath rot of rice.

Evaluation of possible biological control of Fusarium concentricum sp. using plant extracts and antagonistic species of microbes in vitro

Background:Fusariumconcentricum is one of the most devastating fungi responsible for fruit and vegetable crops rot worldwide. The present study was designed to find an ecofriendly control measure for pathogenic Fusariumconcentricum, using suitable bioagents.

Methods: Medicinal plant extracts were evaluated or their antifungal activities against Fusariumconcentricum using the poisoned food and serial dilution methods. Antagonistic potency of some nonpathogenic microbes was also assessed on Fusariumconcentricum using the dual culture method.

Results: Highest inhibition of growth of Fusarium  concentricum was observed with 68.1% (0.389 mg per 90 mm Petri plate) of mycelia on Coccinia grandis plant leaf extract, in comparison to the control grown with 100.0% (1.22 mg/dish). The tested plants extract showed MIC values rages of 80-150 µg/ml on the isolated fungus. The highest inhibition of radial growth was observed using  Trichoderma viride on Fusarium concentricum (46.01% inhibition).

Conclusions: The findings of present study would be benevolent for antifungal drug development to control Fusariumconcentricum causing fruit and vegetable rot.

Two Unrecorded Apiospora Species Isolated from Marine Substrates in Korea with Eight New Combinations (A. piptatheri and A. rasikravindrae)

Although Apiospora Sacc. has previously been considered a sexual morph of Arthrinium species on the basis of phylogenetic, morphological, and ecological diagnoses, a recent study delimited these as different species. Recently, 14 species, including eight new species, of marine Arthrinium have been reported from Korea. Six known species have previously been renamed as species in the genus Apiospora (A. arundinis, A. marii, A. piptatheri, A. rasikravindrae, A. sacchari, and A. saccharicola). However, the eight new species of marine Arthrinium (Ar. agari, Ar. arctoscopi, Ar. fermenti, Ar. koreanum, Ar. marinum, Ar. pusillispermum, Ar. sargassi, and Ar. taeanense) are yet to be studied, and thus the taxonomic status of these species remains to be clarified. In this study, we conducted phylogenetic analyses using the internal transcribed spacer, 28S large subunit ribosomal RNA gene, translation elongation factor 1-alpha, and beta-tubulin regions to confirm the phylogenetic position of these eight species. Based on these analyses, we re-identified the eight Arthrinium species as new combinations in Apiospora. Additionally, among the six known Apiospora species, two (A. piptatheri and A. rasikravindrae) have not previously been recorded in Korea. On the basis of morphological and molecular analyses, we report these as new species in Korea. Herein, we present scanning electron micrographs detailing the morphologies of these species, along with phylogenetic trees and detailed descriptions.

Weeds Harbor Fusarium Species that Cause Malformation Disease of Economically Important Trees in Western Mexico

Mango malformation disease (MMD) caused by Fusarium spp. is an important limiting factor in most production areas worldwide. Fusarium mexicanum and F. pseudocircinatum have been reported as causing MMD in Mexico. These two pathogens also cause a similar disease in Swietenia macrophylla (big-leaf mahogany malformation disease) in central western Mexico, and F. pseudocircinatum was recently reported as causing malformation disease in Tabebuia rosea (rosy trumpet) in the same region. These studies suggest that additional plant species, including weeds, might be hosts of these pathogens. The role that weed hosts might have in the disease cycle is unknown. The objectives of this work were to recover Fusarium isolates from understory vegetation in mango orchards with MMD, identify the Fusarium isolates through DNA sequence data, and determine whether F. mexicanum is capable of inducing disease in the weedy legume Senna uniflora (oneleaf senna). Additional objectives in this work were to compare Fusarium isolates recovered from weeds and mango trees in the same orchards by characterizing their phylogenetic relationships, assessing in vitro production of mycotoxins, and identifying their mating type idiomorph. A total of 59 Fusarium isolates from five species complexes were recovered from apical and lateral buds from four weed species. Two of the species within the F. fujikuroi species complex are known to cause MMD in Mexico. Trichothecene production was detected in five isolates, including F. sulawense and F. irregulare in the F. incarnatum-equiseti species complex and F. boothii in the F. sambucinum species complex. Both mating types were present among mango and weed isolates. This is the first report of herbaceous hosts harboring Fusarium species that cause mango malformation in Mexico. The information provided should prove valuable for further study of the epidemiological role of weeds in MMD and help manage the disease.

Patterns of Diversity of Fusarium Fungi Contaminating Soybean Grains

Soybean is an important, high protein source of food and feed. However, like other agricultural grains, soybean may pose a risk to human and animal health due to contamination of the grains with toxigenic Fusaria and associated mycotoxins. In this study, we investigated the diversity of Fusaria on a panel of 104 field isolates obtained from soybean grains during the growing seasons in 2017-2020. The results of species-specific PCR analyses showed that Fusarium avenaceum was the most common (n = 40) species associated with soybean grains in Poland, followed by F. equiseti (n = 22) and F. sporotrichioides (11 isolates). A set of isolates, which was not determined based on PCR analyses, was whole genome sequenced. Multiple sequence analyses using tef-1α, top1, rpb1, rpb2, tub2, pgk, cam and lsu genes showed that most of them belonged to Equiseti clade. Three cryptic species from this clade: F. clavum, F. flagelliforme and FIESC 31 (lacking Latin binomial) were found on soybean for the first time. This is the first report demonstrating the prevalence of Fusaria on soybean grains in Poland.

Fungal diversity notes 1387-1511: taxonomic and phylogenetic contributions on genera and species of fungal taxa

This article is the 13th contribution in the Fungal Diversity Notes series, wherein 125 taxa from four phyla, ten classes, 31 orders, 69 families, 92 genera and three genera incertae sedis are treated, demonstrating worldwide and geographic distribution. Fungal taxa described and illustrated in the present study include three new genera, 69 new species, one new combination, one reference specimen and 51 new records on new hosts and new geographical distributions. Three new genera, Cylindrotorula (Torulaceae), Scolecoleotia (Leotiales genus incertae sedis) and Xenovaginatispora (Lindomycetaceae) are introduced based on distinct phylogenetic lineages and unique morphologies. Newly described species are Aspergillus lannaensis, Cercophora dulciaquae, Cladophialophora aquatica, Coprinellus punjabensis, Cortinarius alutarius, C. mammillatus, C. quercoflocculosus, Coryneum fagi, Cruentomycena uttarakhandina, Cryptocoryneum rosae, Cyathus uniperidiolus, Cylindrotorula indica, Diaporthe chamaeropicola, Didymella azollae, Diplodia alanphillipsii, Dothiora coronicola, Efibula rodriguezarmasiae, Erysiphe salicicola, Fusarium queenslandicum, Geastrum gorgonicum, G. hansagiense, Helicosporium sexualis, Helminthosporium chiangraiensis, Hongkongmyces kokensis, Hydrophilomyces hydraenae, Hygrocybe boertmannii, Hyphoderma australosetigerum, Hyphodontia yunnanensis, Khaleijomyces umikazeana, Laboulbenia divisa, Laboulbenia triarthronis, Laccaria populina, Lactarius pallidozonarius, Lepidosphaeria strobelii, Longipedicellata megafusiformis, Lophiotrema lincangensis, Marasmius benghalensis, M. jinfoshanensis, M. subtropicus, Mariannaea camelliae, Melanographium smilaxii, Microbotryum polycnemoides, Mimeomyces digitatus, Minutisphaera thailandensis, Mortierella solitaria, Mucor harpali, Nigrograna jinghongensis, Odontia huanrenensis, O. parvispina, Paraconiothyrium ajrekarii, Parafuscosporella niloticus, Phaeocytostroma yomensis, Phaeoisaria synnematicus, Phanerochaete hainanensis, Pleopunctum thailandicum, Pleurotheciella dimorphospora, Pseudochaetosphaeronema chiangraiense, Pseudodactylaria albicolonia, Rhexoacrodictys nigrospora, Russula paravioleipes, Scolecoleotia eriocamporesi, Seriascoma honghense, Synandromyces makranczyi, Thyridaria aureobrunnea, Torula lancangjiangensis, Tubeufia longihelicospora, Wicklowia fusiformispora, Xenovaginatispora phichaiensis and Xylaria apiospora. One new combination, Pseudobactrodesmium stilboideus is proposed. A reference specimen of Comoclathris permunda is designated. New host or distribution records are provided for Acrocalymma fici, Aliquandostipite khaoyaiensis, Camarosporidiella laburni, Canalisporium caribense, Chaetoscutula juniperi, Chlorophyllum demangei, C. globosum, C. hortense, Cladophialophora abundans, Dendryphion hydei, Diaporthe foeniculina, D. pseudophoenicicola, D. pyracanthae, Dictyosporium pandanicola, Dyfrolomyces distoseptatus, Ernakulamia tanakae, Eutypa flavovirens, E. lata, Favolus septatus, Fusarium atrovinosum, F. clavum, Helicosporium luteosporum, Hermatomyces nabanheensis, Hermatomyces sphaericoides, Longipedicellata aquatica, Lophiostoma caudata, L. clematidis-vitalbae, Lophiotrema hydei, L. neoarundinaria, Marasmiellus palmivorus, Megacapitula villosa, Micropsalliota globocystis, M. gracilis, Montagnula thailandica, Neohelicosporium irregulare, N. parisporum, Paradictyoarthrinium diffractum, Phaeoisaria aquatica, Poaceascoma taiwanense, Saproamanita manicata, Spegazzinia camelliae, Submersispora variabilis, Thyronectria caudata, T. mackenziei, Tubeufia chiangmaiensis, T. roseohelicospora, Vaginatispora nypae, Wicklowia submersa, Xanthagaricus necopinatus and Xylaria haemorrhoidalis. The data presented herein are based on morphological examination of fresh specimens, coupled with analysis of phylogenetic sequence data to better integrate taxa into appropriate taxonomic ranks and infer their evolutionary relationships.

Phylogeny and pathogenicity of Fusarium solani species complex (FSSC) associated with potato tubers

Potato (Solanum tuberosum L.) is one of the known five crops cultivated throughout the world after corn, barley, cereals, rice, and wheat, due to its content of high carbohydrates. In developing countries, potatoes are especially had valuable contents as a rich source of starch, vitamins C and B6, and essential amino acids. Fusarium solani species complex (FSSC) is one of the prevalent pathogens of potato, causing dry rot in Upper Egypt. In this study, FSSC were isolated and identified from potato tubers based on the morphological and molecular characteristics. F. solani isolates (187) were isolated from infected and noninfected potato tubers collected from various markets in Upper Egypt. Based on the morphology observations, sequence data from amplifying β-tubulin, and specific translation elongation factor (TEF-1α) genes, all of the chosen 88 FSSC isolates were grouped into three major groups (F. keratoplasticum, F. falciforme, and F. solani). All the tested FSSC were able to produce amylases. The selected isolates were examined for their pathogenic ability on healthy potato tubers, which exhibited pathogenic effects; with lesions sizes were quite variable. F. solani SVUFs73 showed a highly virulent effect.

Pest categorisation of Fusarium brachygibbosum

The EFSA Plant Health Panel performed a pest categorisation of Fusarium brachygibbosum Padwick. F. brachygibbosum is a well-characterised fungal plant pathogen with opportunistic behaviour, mostly isolated along with other fungal pathogens in symptomatic hosts. It has been reported from Africa, America, Asia and Oceania where it is has been associated with a wide range of symptoms on approximately 25 cultivated and non-cultivated plant species. The pathogen has been reported in Italy in soil/marine sediments and in quinoa (Chenopodium quinoa) and durum wheat (Triticum turgidum subsp. durum) seeds. The pathogen is not included in the EU Commission Implementing Regulation 2019/2072. This pest categorisation focused on a selected range of host plant species on which F. brachygibbosum fulfilled Koch's postulates and was formally identified by multilocus gene sequencing analysis. Host plants for planting, seed of host plants and soil and other substrates originating in infested third countries are main pathways for the entry of the pathogen into the EU. There are no reports of interceptions of F. brachygibbosum in the EU. Host availability and climate suitability factors occurring in the EU are favourable for the establishment of the pathogen in Member States (MSs). Phytosanitary measures are available to prevent the introduction of the pathogen into the EU. Additional measures are available to mitigate the risk of entry and spread of the pathogen in the EU. Despite the low aggressiveness observed in some reported hosts, it has been shown that, in the areas of its present distribution, the pathogen has a direct impact on certain hosts (e.g. almond, onion, soybean, tobacco) that are also relevant for the EU. The Panel concludes that F. brachygibbosum satisfies all the criteria to be regarded as a potential Union quarantine pest. However, high uncertainty remains regarding the distribution of the pathogen in the EU and some uncertainty exists about its potential impact in the EU. Specific surveys and re-evaluation of Fusarium isolates in culture collections could reduce these uncertainties.

Fungal burn wound infection caused by Fusarium dimerum: A case series on a rare etiology

Introduction

Fusarium dimerum is a filamentous mold associated with poor outcomes in immunocompromised hosts and burn victims. It can be acquired via inhalation or through skin dehiscence.

Methods

Our work presents a Case series of 8 patients from ages 3–57 years who were admitted with multiple burn wounds over the past 6 months. After initial stabilization measures, they all underwent debridement for the lesions after negative initial fungal cultures. The 44-year-old male was the first patient to develop punched-out eruptions on burn areas 7 days after admission; all the other patients experienced similar lesions during the next 6 days. Tissue cultures of the lesions exhibited Fusarium dimerum growth. The patients were managed accordingly with amphotericin B or voriconazoles. All the patients recovered except the 11-year-old boy, who expired on day 9 due to ARDS and sepsis complications.

Outcomes

Infection with Fusarium dimerum carries a high risk of dissemination in burn infections. Hence, appropriate screening should be carried out via histologic and mycologic diagnostics early in the disease course.

Conclusion

Considering the sparse literature that is available regarding Fusarium infection in burn victims, this study aims to improve the knowledge surrounding different facets of this disease including its epidemiology, diagnosis, management, and the need to maintain high suspicion of this fungal disease in burn patients.

•

Fusarium dimerum is a filamentous mold associated with poor outcomes in immunocompromised hosts and burn victims. It can be acquired via inhalation or through skin dehiscence.

•

Our work presents a Case series of 8 patients from ages 3–57 years who were admitted with multiple burn wounds over the past 6 months. After initial stabilization measures, they all underwent debridement for the lesions after negative initial fungal cultures.

•

Infection with Fusarium dimerum carries a high risk of dissemination in burn infections. Hence, appropriate screening should be carried out via histologic and mycologic diagnostics early in the disease course.

Species Diversity and Toxigenic Potential of Fusarium incarnatum-equiseti Species Complex Isolates from Rice and Soybean in China

Fusarium incarnatum-equiseti species complex (FIESC) strains are generally considered moderately virulent to many agricultural crops and produce a variety of mycotoxins, which represent a serious threat to food safety and public health. The occurrence of the FIESC strain in agricultural crops has been reported in various climatic regions, but detailed information on the species composition and toxigenic ability is rare in China. In this study, phylogenetic analyses were performed with combined sequences of EF-1a and RPB2 of 186 Fusarium isolates obtained from rice (Oryza sativa) and soybean (Glycine max). Twelve species were identified and 156 of the isolates were resolved within the Incarnatum clade of the FIESC species. Host influenced the population composition: rice isolates belonged to 12 species, among which FIESC 16, 18, and 24 strains were predominant; whereas five species were found among soybean isolates and FIESC 1, 16, and 18 strains dominated. Forty-three isolates were arbitrarily selected and analyzed for their Tri gene sequences and mycotoxigenic potential. Phylogenetic results based on the combined Tri5, Tri7, and Tri13 sequences were coincident with those from housekeeping markers. Type-A and -B trichothecenes were the main metabolites. Diacetoxyscirpenol was detected in all strains at varying concentrations. Nivalenol, 4-acetyl nivalenol, 3-acetyl deoxynivalenol, and neosolaniol were produced in members of the FIESC 1, 3, 7, 8, 15, 16, 17, and 18 strains. Our findings contribute valuable phylogenetic and toxigenic information necessary for the risk evaluation of mycotoxins in agricultural products.

Phylogeny and mycotoxin profile of Fusarium species isolated from sugarcane in Southern Iran

Sugarcane is an important crop in Southern Iran for agri-food, energy, and pharmaceutical industries. Among the pathogens that colonize sugarcane, mycotoxigenic Fusarium species are reason of serious concern for both their pathogenicity on plants and ability to produce harmful mycotoxins to humans and animals. We studied 104 Fusarium strains, selected within a wider Fusarium set isolated from sugarcane in Southern Iran, for molecular identification, phylogeny and mycotoxin analyses. Most of Fusarium strains belonged to Fusarium fujikuroi Species Complex (FFSC) and identified mainly as F. proliferatum, at minor extent as F. sacchari, and rarely as F. thapsinum, and F. verticillioides. Moreover, 14 strains identified as FFSC could not be assigned to any known species, although they were phylogenetically closely related to F. andiyazi, likely representing a new phylogenetic species. A subset of FFSC strains were analyzed for in vitro production of fumonisins (FBs), beauvericin (BEA), and enniatins (ENNs). Fusarium proliferatum strains produced FBs at high amount, and, at a lesser extent, BEA, and ENNs; F.sacchari produced only BEA and B ENNs at very low level; Fusarium sp. strains produced only B ENNs. The paper provides new insights on the genetic diversity of Fusarium species and their mycotoxin profile occurring on sugarcane in Iran.

Mycotoxin Production in Fusarium According to Contemporary Species Concepts

Fusarium is one of the most important genera of plant-pathogenic fungi in the world and arguably the world's most important mycotoxin-producing genus. Fusarium species produce a staggering array of toxic metabolites that contribute to plant disease and mycotoxicoses in humans and other animals. A thorough understanding of the mycotoxin potential of individual species is crucial for assessing the toxicological risks associated with Fusarium diseases. There are thousands of reports of mycotoxin production by various species, and there have been numerous attempts to summarize them. These efforts have been complicated by competing classification systems based on morphology, sexual compatibility, and phylogenetic relationships. The current depth of knowledge of Fusarium genomes and mycotoxin biosynthetic pathways provides insights into how mycotoxin production is distributedamong species and multispecies lineages (species complexes) in the genus as well as opportunities to clarify and predict mycotoxin risks connected with known and newly described species. Here, we summarize mycotoxin production in the genus Fusarium and how mycotoxin risk aligns with current phylogenetic species concepts.

Genetic Diversity of the Fusarium oxysporum Complex Isolated from the Grassland Biome of South Africa

The genetic diversity of pathogenic members of the Fusarium oxysporum species complex (FOSC) has been intensively studied worldwide, yet strains occurring in native soils with low anthropogenic disturbance remain poorly understood. This study focused on 355 F. oxysporum isolates from soils with low anthropogenic activity obtained from the grassland biome of South Africa. Analysis of the translation elongation factor 1-alpha (tef-1α) gene revealed high levels of sequence type diversity within the soil population in comparison with the global dataset. Phylogenetic relationships of the South African isolates revealed that four nested within FOSC clade 1. This is the first report of members of the basal clade recovered from ecosystems with low anthropogenic disturbance from Sub-Saharan Africa. The remaining strains nested within clades 2 to 5. This study contributes significantly to our understanding of the distribution of the FOSC in natural systems as we show that FOSC populations in the South African grassland biome are genetically diverse. This fills in our knowledge gap because previous studies reported only on the occurrence and diversity of the FOSC isolated from plant debris in South Africa. This is the first comprehensive survey of fusaria from grassland soils with low anthropogenic disturbance in South Africa.

Fusarium incarnatum-equiseti Species Complex Causing Root Rot Disease on Leymus chinensis in China

Leymus chinensis (Trin.) Tzvel. is a rhizomatous grass widely grown in the grasslands of Eurasia. With strong fertility and stress resistance, L. chinensis makes an excellent pasture and mowing grass, contributing to animal husbandry and thus playing an important role in the local economy of the northern grassland area in China (Baoyin et al. 2014). During August to September 2019, diseased roots of L. chinensis were collected from an artificially planted grassland (40°47'44" N, 111°43'58″ E, alt. 1049 m) in Shaerqin County, Hohhot, China. Infected plants were scattered across the field with disease incidence up to 2%. Symptoms observed were wilted plants and rotten roots. In order to identify the causal pathogen of root rot on L. chinensis, symptomatic pieces (5 × 5 mm) of grass roots were excised and surface sterilized with 75% ethanol for 3-5 s followed by 1% NaClO for 2-3 min, rinsed three times with sterile distilled water, and placed on water agar and incubated at 25°C for 3 days. The mycelia were cut and transferred onto potato dextrose agar (PDA) for subculture. A fungus was consistently isolated, and a strain, named LCH054, was obtained by hyphal tip culture. Culture developed as white and fluffy aerial mycelia, with diffused pink pigment on the reverse side of PDA after culturing at 25℃ for 7 days. A culture of LCH054 was transferred to carnation leaf agar (CLA) (Li et al. 2014) and incubated at 25°C for 10 days. Microconidia were absent but macroconidia were produced. Macroconidia were hyaline, sickle-shaped, and had 4 to 7 septa, 19.8 to 63.6 (mean 43.8) × 1.8 to 5.7 (mean 3.2) μm (n = 100). Chlamydospores were ellipsoidal or subglobose, with thick walls in clumps or chains. All morphological characteristics of LCH054 resembled Fusarium equiseti (Leslie and Summerell 2006). The primers of the internal transcribed spacer (ITS) region (White et al. 1990) and translation elongation factor 1α gene (TEF-1α) (O'Donnell et al. 1998) were used to amplify the isolate, and the fragments were sequenced. BLASTn search in the NCBI database using the ITS and TEF-1α sequences revealed 99 to 100% similarities with F. equiseti. BLAST analysis of the ITS and TEF-1α sequencies in the FUSARIUM-ID database showed them to have 99.21% (500 bp out of 504 bp) and 99.52% (622 bp out of 625 bp) similarities with the Fusarium incarnatum-equiseti species complex (FIESC) (strain NRRL 45997) (O'Donnell et al. 2009), respectively. The ITS and TEF1-α sequences were deposited in GenBank as accession numbers MT937067 and MT947530, respectively. The strain LCH054 was identified as a member of the FIESC based on morphological and molecular characteristics. For the pathogenicity test, one hundred of L. chinensis seeds were planted into five pots (12 cm [diameter]) × 15 cm [high]) and kept in a greenhouse under a 16-h photoperiod with temperatures of 20-25°C and 40% relative humidity. The conidial suspension of LCH054 was prepared by washing 7-day old fungal culture grown on CLA medium using sterile deionized water. Conidia were filtered through three layers of sterile cheese cloth, counted, and adjusted to 1 × 105 conidia/ml with a hemocytometer. Forty 1-month-old healthy plants (four pots) were inoculated with 400 ml of conidia suspension using the root drenching method, whereas the inoculum was replaced with 100 ml sterile water on control plants (one pot). Fourteen days after inoculation, all inoculated plants showed the typical symptoms of root rot identical to those observed in the field, whereas the control plants remained healthy. LCH054 was re-isolated from the inoculated plants and identified by the morphological and molecular approaches as described above. To the best of our knowledge, this is the first report of root rot caused by F. incarnatum-equiseti on L. chinensis in China as well as worldwide. The presence of the pathogen could cause significant economic losses in L. chinensis production. For this reason, strategies for the management and control of this disease should be developed and implemented.

Identification and Description of a New Pathogen Causing Flower Dry Rot on Passiflora edulis in China

Passiflora edulis Sims (passion fruit) is an economically important fruit crop. However, a new flower dry rot has occurred in orchards located in Zhanjiang, China, and has led to serious production loss. Its disease incidence is approximately 30 to 40%. A total of 221 isolates of Fusarium sp. were obtained from samples of three types of symptomatic flowers. Three representative single-spore isolates (PaB-1, PaB-2, and PaB-3) from each type were used for pathogenicity tests, multilocus phylogenetic analyses, and morphological descriptions. Pathogenicity tests of buds of 5-month-old P. edulis plants showed symptoms similar to those observed in nature, and Koch's postulates were achieved. By comparing 36 typical species from the FUSARIUM-ID database, multilocus phylogenetic analyses showed that the sequences of TEF1, RPB2, and ITS of these isolates belong to the Incarnatum clade of the F. incarnatum-equiseti species complex (FIESC-17-a) with an independent branch. Therefore, the pathogenic isolates were identified as F. pernambucanum (FIESC-17-a). Moreover, in this study, the conidial anastomosis tubes were first observed in the FIESC. This is the first report of flower dry rot on P. edulis caused by F. pernambucanum. Further studies should be performed to determine effective disease management strategies.

Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.

Fungicolous Fusarium Species: Ecology, Diversity, Isolation, and Identification

Fusarium species can have different lifestyles, including those of endophytes, parasites, or pathogens of plants, as well as pathogens or mutualists of animals. Fungicolous Fusarium species have been also reported in some studies, however, the information on the Fusarium interactions with other fungi is still unclear and the diversity of fungicolous Fusarium species is poorly known. In this study, we provide a survey of fungicolous Fusarium species and their hosts, and instructions for their isolation and identification. According to the survey, 80 fungicolous Fusarium isolates were reported associated with 36 host species and 32 fungal genera. The fungicolous isolates belong to 24 species grouped in nine species complexes (SC)-Fusarium chlamydosporum SC, Fusarium fujikuroi SC, F. heterosporum SC, F. lateritium SC, F. oxysporum SC, F. incarnatum-equiseti SC, F. sambucinum SC, F. solani SC (=Neocosmospora genus), and F. tricinctum SC. Fusarium associations with other fungi were predominantly necrotrophic. The prevalent fungal hosts for fungicolous Fusarium isolates were members of the sub-kingdom Dikarya, mostly microfungi. Other hosts belong to the sub-kingdom Mucoromyceta of the kingdom Fungi and to the phylum Oomycota (fungal-like organisms) of kingdom Straminipila. With this review, we hope to highlight the fungicolous associations of Fusarium, and to expand the understanding of the ecology and diversity of these fungi.

Species diversity and mycotoxin production by members of the Fusarium tricinctum species complex associated with Fusarium head blight of wheat and barley in Italy

Fusarium head blight (FHB) is a global cereal disease caused by a complex of Fusarium species. In Europe, the main species responsible for FHB are F. graminearum, F. culmorum and F. poae. However, members of the F. tricinctum species complex (FTSC) have become increasingly important. FTSC fusaria can synthesize mycotoxins such as moniliformin (MON), enniatins (ENNs) and several other biologically active secondary metabolites that could compromise food quality. In this study, FTSC isolates primarily from Italian durum wheat and barley, together with individual strains from four non-graminaceous hosts, were collected to assess their genetic diversity and determine their potential to produce mycotoxins in vitro on rice cultures. A multilocus DNA sequence dataset (TEF1, RPB1 and RPB2) was constructed for 117 isolates from Italy and 6 from Iran to evaluate FTSC species diversity and their evolutionary relationships. Phylogenetic analyses revealed wide genetic diversity among Italian FTSC isolates. Among previously described FTSC species, F. avenaceum (FTSC 4) was the most common species in Italy (56/117 = 47.9%) while F. tricinctum (FTSC 3), and F. acuminatum (FTSC 2) accounted for 11.1% (13/117) and the 8.5% (10/117), respectively. The second most detected species was a new and unnamed Fusarium sp. (FTSC 12; 32/117 = 19%) resolved as the sister group of F. tricinctum. Collectively, these four phylospecies accounted for 111/117 = 94.9% of the Italian FTSC collection. However, we identified five other FTSC species at low frequencies, including F. iranicum (FTSC 6) and three newly discovered species (Fusarium spp. FTSC 13, 14, 15). Of the 59 FTSC isolates tested for mycotoxin production on rice cultures, 54 and 55 strains, respectively, were able to produce detectable levels of ENNs and MON. In addition, we confirmed that the ability to produce bioactive secondary metabolites such as chlamydosporol, acuminatopyrone, longiborneol, fungerin and butanolide is widespread across the FTSC.

Recent developments in less known and multi-resistant fungal opportunists

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

Water distribution systems in Sardinian hospitals host invasive clonal lineages of the Fusarium oxysporum and Fusarium solani species complexes

Several Fusarium species cause disease on human hosts, including commonly fatal infections in immunocompromised individuals. Recently, cases of hospitalized patients affected by fusaria were reported in the Tyrrhenian Island of Sardinia, Italy. To precisely characterize the Fusarium species and haplotypes present in hospitals of the region, a multilocus DNA sequence typing (MLST) approach was applied. Water distribution systems in four departments belonging to four Sardinian hospitals were sampled. Fusarium species and sequence types (STs) were identified using MLST based on sequences of the elongation factor 1-alpha (EF-1α) gene, the nuclear ribosomal DNA intergenic spacer region (IGS rDNA), and/or a portion of the second-largest subunit of RNA polymerase (RPB2) gene. The majority of isolates obtained from Sardinian hospitals (90.7%) were identified as representatives of the Fusarium oxysporum species complex (FOSC), followed by those of the F. solani species complex (FSSC) (8.2%), and F. dimerum (1.1% of all isolates). Ten STs were found among the FOSC and FSSC, with more than 60% of the isolates identified as either FOSC ST 33 or FSSC 1 (F. petroliphilum). More than half of the FOSC isolates obtained from the water systems in all four hospitals belonged to the worldwide distributed clonal lineage ST 33. This haplotype is the most prevalent among the FOSC in different countries, being responsible for the vast majority of cases of human fusariosis.

Disinfectants in a Hemodialysis Setting: Antifungal Activity Against Aspergillus and Fusarium Planktonic and Biofilm Cells and the Effect of Commercial Peracetic Acid Residual in Mice

Aspergillus and Fusarium cause a broad spectrum of infections in humans, mainly in immunocompromised patients. Among these, patients undergoing hemodialysis are highly susceptible to infections, requiring a constant and adequate environmental disinfection program. Nevertheless, monitoring the residual disinfectants can contribute to the morbidity and mortality reduction in these patients. Here, we evaluated the susceptibility of Aspergillus spp. (n=19) and Fusarium spp. (n=13) environmental isolates against disinfectants (acetic acid, citric acid, peracetic acid, sodium hypochlorite, and sodium metabisulphite) at different concentrations and time exposures. Also, we investigated the in vivo toxicity of the peracetic acid residual concentration in mice. Fusarium isolates were identified by F. equiseti, F. oxysporum and F. solani while Aspergillus presented clinically relevant species (A. fumigatus, A. niger and A. terreus) and environmental ones. Against planktonic cells, only two disinfectants (acetic acid and sodium hypochlorite) showed a fungicidal effect on Fusarium spp., while only one (sodium hypochlorite) was effective against Aspergillus spp. Both fungi formed robust in vitro biofilms with large amounts of the extracellular matrix, as evidenced by electron micrographs. Exposure of fungal biofilms to disinfectants showed sensitivity to three (acetic, citric, and peracetic acids), although the concentrations and times of exposure varied according to the fungal genus. Mice exposure to the residual dose of peracetic acid during 60 weeks showed anatomopathological, hematological, and biochemical changes. The implementation of news control measures and those that already exist can help reduce infections, the second cause of death and morbidity in these patients, besides providing safety and well-being to them, a priority of any quality health program.

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).

Screening for Susceptibility of Macadamia to Euwallacea fornicatus and its Fungal Symbiont Fusarium euwallaceae

The polyphagous shothole borer (Euwallacea fornicatus, PSHB), an ambrosia beetle, with its fungal symbiont, Fusarium euwallaceae, is responsible for Fusarium dieback (FD) in a wide range of woody hosts. In 2019, the first suspected case of E. fornicatus was reported in macadamia in South Africa. The aims of this study were to confirm the E. fornicatus report and thereafter to assess the susceptibility of commercially planted macadamia cultivars to FD caused by F. euwallaceae. The identities of the beetle and associated fungal symbionts were confirmed by means of DNA sequence analysis of the 28S ribosomal large subunit gene for beetles and the internal transcribed spacer region for fungi. Isolates identified as Fusarium species were further characterized by phylogenetic analysis of the translation elongation factor 1α and the β-tubulin gene regions. Thereafter, Koch's postulates regarding F. euwallaceae were fulfilled on a mature Macadamia integrifolia tree planted at the experimental farm of the University of Pretoria. In order to determine susceptibility against FD, additional cultivar screening was conducted on nine commercially planted cultivars by means of pathogenicity trials using sterilized or inoculated toothpicks inserted into detached branches. Detached branch inoculations showed no significant lesion development six weeks post inoculation, except for cultivar 816. The restricted growth of F. euwallaceae observed in macadamia tissues therefore suggests that macadamia may not be a suitable host for F. euwallaceae and that the threat of FD in macadamia in the event of E. fornicatus infestation is less than for other E. fornicatus hosts. Future work on beetle attraction to macadamia is recommended for a more comprehensive understanding of the interaction between E. fornicatus and its fungal symbionts and macadamia.

Seed Banks as Incidental Fungi Banks: Fungal Endophyte Diversity in Stored Seeds of Banana Wild Relatives

Seed banks were first established to conserve crop genetic diversity, but seed banking has more recently been extended to wild plants, particularly crop wild relatives (CWRs) (e.g., by the Millennium Seed Bank (MSB), Royal Botanic Gardens Kew). CWRs have been recognised as potential reservoirs of beneficial traits for our domesticated crops, and with mounting evidence of the importance of the microbiome to organismal health, it follows that the microbial communities of wild relatives could also be a valuable resource for crop resilience to environmental and pathogenic threats. Endophytic fungi reside asymptomatically inside all plant tissues and have been found to confer advantages to their plant host. Preserving the natural microbial diversity of plants could therefore represent an important secondary conservation role of seed banks. At the same time, species that are reported as endophytes may also be latent pathogens. We explored the potential of the MSB as an incidental fungal endophyte bank by assessing diversity of fungi inside stored seeds. Using banana CWRs in the genus Musa as a case-study, we sequenced an extended ITS-LSU fragment in order to delimit operational taxonomic units (OTUs) and used a similarity and phylogenetics approach for classification. Fungi were successfully detected inside just under one third of the seeds, with a few genera accounting for most of the OTUs-primarily Lasiodiplodia, Fusarium, and Aspergillus-while a large variety of rare OTUs from across the Ascomycota were isolated only once. Fusarium species were notably abundant-of significance in light of Fusarium wilt, a disease threatening global banana crops-and so were targeted for additional sequencing with the marker EF1α in order to delimit species and place them in a phylogeny of the genus. Endophyte community composition, diversity and abundance was significantly different across habitats, and we explored the relationship between community differences and seed germination/viability. Our results show that there is a previously neglected invisible fungal dimension to seed banking that could well have implications for the seed collection and storage procedures, and that collections such as the MSB are indeed a novel source of potentially useful fungal strains.