Fusarium Species Complex Research Articles

Morphological characterization, pathogenicity screening, and molecular identification of Fusarium spp. isolates causing post-flowering stalk rot in maize.

Post flowering stalk rot (PFSR) of maize caused by the Fusarium species complex is a serious threat to maize production worldwide. The identification of Fusarium species causing PFSR based on morphology traditionally relies on a small set of phenomic characteristics with only minor morphological variations among distinct Fusarium species. Seventy-one isolates were collected from 40 sites in five agro-climatic zones of India to assess the diversity of Fusarium spp. associated with maize crops showing symptoms of PFSR in the field. To investigate the pathogenicity of Fusarium spp. causing PFSR sixty isolates were toothpick inoculated between the first and second node at 55 days after sowing during the tassel formation stage of the crop in Kharif (Rainy season), and Rabi (Winter season) season field trials. Ten most virulent Fusarium isolates, based on the highest observed disease index, were identified by homology and phylogenetic analyses of partial sequences of the translation elongation factor 1 α (Tef-1α). Based on morphological traits such as mycelial growth patterns and mycelial pigmentation, Fusarium isolates were divided into nine clusters. The isolates were judged to be virulent based on their ability to decrease seedling vigour in in-vivo situations and high disease severity in field experiments. Pathogenicity test during the Kharif season showed 12 isolates with virulent disease symptoms with a mean severity ranging between 50 to 67 percent disease index (PDI) whereas in Rabi season, only five isolates were considered virulent, and the mean severity ranged between 52 to 67 PDI. Based on pathological characterization and molecular identification, 10 strains of Fusarium species namely, Fusarium acutatum (2/10), Fusarium verticillioides (Syn. Gibberella fujikuroi var. moniliformis) (7/10), Fusarium andiyazi (2/10) recorded the highest diseases index. All these species are part of the Fusarium fujikuroi species complex (FFSC). The distribution of virulent isolates is specific to a geographical location with a hot humid climate. Increased knowledge regarding the variability of Fusarium spp. responsible for PFSR of maize occurring across wide geographical locations of India will enable more informed decisions to be made to support the management of the disease, including screening for resistance in maize-inbred lines.

Morphological and cultural characterization of two Fusarium isolates causing wheat fusarium head blight in Algeria

In Algeria, fusarium head blight is a serious fungal disease of wheat caused by Fusarium genus. The study of the epidemiological cycle of the disease in the field is always hampered by a major problem which is the identification of the parasitic complex of Fusarium species. These species can only be identified after Petri dish culture and observation of a set of morphological criteria such as color, cultural aspect of colonies, growth rate of mycelium and the form of isolate macroconidia. To this end, the objective of this present study is to identify two Fusarium isolates based on a set of morphological and cultural criteria mentioned above. The results obtained for all the morphological characters studied show phenotypic variability between the two isolates. Based on these results, we were able to characterize these two isolates as F. graminearum and F. culmorum. Indeed, morphological and cultural characterization, although important, remains insufficient. It should therefore be further investigated by molecular characterization, in order to highlight any differences between the two isolates studied.

Seedling growth promotion and potential biocontrol against phytopathogenic Fusarium by native rhizospheric Pseudomonas spp. strains from Amarillo Zamorano maize landrace

Maize is one of the most important staple crops around the word. In Mexico, Los Altos de Jalisco is an agricultural region with the highest production of maize with rainfed irrigation, an agronomic management based on the use of no longer sustainable agrochemicals, and sowing of coated seeds of different commercial origin. Nowadays, the microbiota associated to the rhizosphere of native landraces is considered a reservoir of microbial resources with the potential to promote plant growth and control diseases. With the aim to find ecofriendly and cost-effective alternatives that can reduce the use of agrochemicals at seed germination and seedling growth of maize crop in Los Altos de Jalisco, this study focused on the search of fluorescent Pseudomonas strains as germination and seedlings growth promoters and biocontrol agents of fusariosis in maize, and highlight the importance of Mexican maize landraces as natural reservoirs of plant growth-promoting microorganisms. Samples of rhizospheric soil and seeds were collected from ten maize landraces and a pure line. Pseudomonas and Fusarium strains were isolated and selected by its antagonistic and pathogenic potential, respectively. Pseudomonas strains were phylogenetically identified by a 16S rRNA gene analysis, and Fusarium strains by the phylogenetic analysis of ITS region. The potential of Pseudomonas strains to promote seed germination and seedling/plant growth was explored through metabolic profiles and bioassays to evaluate bacteria-plant-fungus interactions. A total of 57 Fusarium spp. strains were grouped into four different Fusarium species complexes and 14 fluorescent Pseudomonas strains were classified into four Pseudomonas fluorescens subgroups. Pseudomonas strains displayed plant growth promotion and biocontrol capacity by increasing 38%–66% the dry weight of maize seedlings (p < 0.05), 23%–63% growth-inhibition of different Fusarium strains in dual cultures, and a range of 4.5–20 inhibition score based on a rate scale when inoculated in seeds. Pseudomonas spp. metabolic profiles were diverse, but all the strains proved to be innocuous, and Pseudomonas sp. 4L, 10L and 11L showed desirable enzymatic capacities from an agrobiotechnological approach. Additionally, Pseudomonas sp. 4L increased germination and seedling growth of maize, by increasing 20–51% the number of germinated seeds, 16–38% the length of seedling aerial part, 30–140% seedling length of roots, 15–32% seedling fresh weight, and 21–33% seedling dry weight, and reduced 75–96% the damage generated by Fusarium spp. on naturally infected seeds. This study revealed that Pseudomonas sp. 4L and 11L are regional promising ecofriendly and cost-effective alternatives as adjuvants in the nutritional and phytosanitary management at seed germination and seedling growth of maize crop in Los Altos de Jalisco region, and highlight the importance of the rhizosphere microbiome of Mexican maize landrace as natural reservoir of plant growth-promoting microorganisms.

S4.1d In vitro activity of eight antifungals against 3343 filamentous pathogenic fungi collected during 18 years at the French National Reference Center for invasive mycosis and antifungals

S4.1 Treatment of rare mold infections in 2021: the role of new and old antifungals, September 22, 2022, 10:30 AM - 12:00 PM Background & ObjectivesThe NRCMA oversees the surveillance of invasive fungal diseases in France. As part of our expertise, we perform antifungal susceptibility testing based on European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology on all isolates. The antifungal profiles help us monitor the emergence of resistant isolates, determine the susceptibility pattern of wild-type strains to new antifungals, and in specific cases, determine the relationship between clinical failure and selection/emergence of a less susceptible isolate.We review the Minimum inhibitory concentrations (MIC) distribution of eight antifungals on clinical isolates of filamentous fungi identified at the NRCMA from 2003 to 2021.MethodsSpecies identification was performed by a combination of morphological features and multilocus sequencing. Only strains that produced enough conidia or spores were tested. In vitro susceptibility testing was performed according to the EUCAST procedure. Eight antifungal agents were used: triazoles [itraconazole, voriconazole, posaconazole, isavuconazole (since 2015)], echinocandins (caspofungin, micafungin), amphothericin B, and terbinafine. The concentrations inhibiting 50% (MIC50) and 90% (MIC90) of the isolates were determined for species with at least 5 and 10 isolates, respectively. For Aspergillus fumigatus isolates exhibiting high azole MICs, we sequenced the cyp51A gene for mutation screening.ResultsMICs were obtained for 3343 pathogenic strains. We identified Aspergillus spp. including cryptic species (32%), Fusarium spp. (21%), Mucorales (18%), phaeohyphomycetes (10%), i.e., Alternaria spp., Curvularia spp., Fonsecaea, Exophiala, Phaeoacremonium, rare hyphomycetes (9%), i.e., Rasamsonia, Paecilomyces, Trichoderma, Scopulariopsis. Scedosporium spp. (7%) and emergent pathogens such as Nannizziopsis obscura (1%), dimorphic fungi (1%), or to a less extent basidiomycetous molds. Examples of MIC results are presented in Table 1.For the nine genera of the order Mucorales, amphotericin B (AmB) exhibited low MICs except for Cunninghamella species and Saksenaea vasiformis. Posaconazole had variable activity depending on the species (high MIC values were observed for Mucor species) while voriconazole and echinocandins had none.In section Fumigati, amphotericin B MIC values were high due to the intrinsic resistance of cryptic species Aspergillus lentulus and A. udagawae. Other cryptic species were identified such as A. hiratsukae isolates which exhibited low MICs to all antifungals.Members of Aspergillus section Nidulantes such as A. nidulans and A. quadrilineatus showed variable MICs to caspofungin and amphotericin B.Among melanized fungi, Alternaria infectoria and A. alternata species group displayed low MICs of all azoles with the exception of voriconazole.Four Exophiala species were analyzed and had similar azole MICs, E. spinifera being the species with the lowest values.Multi-drug resistant profiles were observed especially in species belonging to Microascales such as Lomentospora prolificans, Microascus cirrosus, and Scopulariopsis brevicaulis. Members of Fusarium species complexes had predictably high MIC values to all antifungals including isavuconazole. Only Fusarium dimerum species complex had low MICs to amphotericin B.Further distribution analysis is ongoing. These large datasets provide a baseline for monitoring the emergence of antifungal resistance in our country and supports the fact that MIC determination should be performed for rare/emergent species and also in case of infections due to cryptic species, which would benefit patient management.

Deoxynivalenol and T-2 Toxin as Major Concerns in Durum Wheat from Italy.

Fusarium Head Blight is a devastating disease of wheat caused by a complex of Fusarium species producing a wide range of mycotoxins. Fusarium species occurrence is variable in different geographical areas and subjected to a continuous evolution in their distribution. A total of 141 durum wheat field samples were collected in different regions of Italy in three years, and analyzed for Fusarium species and related mycotoxin occurrence. Mycotoxin contamination varied according to year and geographical origin. The highest mycotoxin contamination was detected in 2014. Deoxynivalenol was detected with an average of 240 µg/kg only in Central and Northern Italy; and T-2 and HT-2 toxins with an average of 150 µg/kg in Southern Italy. Approximately 80% of samples from Southern Italy in 2013/2014 showed T-2 and HT-2 levels over the EU recommended limits. Fusarium graminearum occurred mostly in Northern Italy, while F. langsethiae occurred in Southern Italy. These data showed that a real mycotoxin risk related to Fusarium exists on the whole in Italy, but varies according with geographical areas and environmental conditions. Consistent monitoring of Fusarium species and related mycotoxin distribution on a long period is worthwhile to generate more accurate knowledge on Fusarium species profile and mycotoxins associated and better establish the climatic change impact on wheat Fusarium epidemiology.

Detection of circulating DNA for the diagnosis of invasive fusariosis: retrospective analysis of 15 proven cases.

Fusariosis ranks third among invasive mould infections. It is frequently diagnosed late due to the lack of specific tools. We designed and evaluated a new qPCR assay with high sensitivity and specificity allowing detection of Fusarium DNA in serum samples up to 18 days before conventional diagnosis.

Diversity of Fusarium Species Isolated from Symptomatic Plants Belonging to a Wide Range of Agri-Food and Ornamental Crops in Lebanon.

Lebanon is a small Mediterranean country with different pedoclimatic conditions that allow the growth of both temperate and tropical plants. Currently, few studies are available on the occurrence and diversity of Fusarium species on Lebanese crops. A wide population of Fusarium strains was isolated from different symptomatic plants in the last 10 years. In the present investigation, a set of 134 representative strains were molecularly identified by sequencing the translation elongation factor, used in Fusarium as a barcoding gene. Great variability was observed, since the strains were grouped into nine different Fusarium Species Complexes (SCs). Fusarium oxysporum SC and Fusarium solani SC were the most frequent (53% and 24%, respectively). Members of important mycotoxigenic SCs were also detected: F. fujikuroi SC (7%), F. sambucinum SC (5%), F. incarnatum-equiseti SC (3%), and F. tricinctum SC (4%). Two strains belonging to F. lateritium SC, a single strain belonging to F. burgessii SC, and a single strain belonging to F. redolens SC were also detected. This paper reports, for the first time, the occurrence of several Fusarium species on Lebanese host plants. The clear picture of the Fusarium species distribution provided in this study can pose a basis for both a better understanding of the potential phytopathological and toxicological risks and planning future Fusarium management strategies in Lebanon.

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.

Fusarium and allied fusarioid taxa (FUSA). 1.

Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced here. Citation: Crous PW, Sandoval-Denis M, Costa MM, Groenewald JZ, van Iperen AL, Starink-Willemse M, Hernández-Restrepo M, Kandemir H, Ulaszewski B, de Boer W, Abdel-Azeem AM, Abdollahzadeh J, Akulov A, Bakhshi M, Bezerra JDP, Bhunjun CS, Câmara MPS, Chaverri P, Vieira WAS, Decock CA, Gaya E, Gené J, Guarro J, Gramaje D, Grube M, Gupta VK, Guarnaccia V, Hill R, Hirooka Y, Hyde KD, Jayawardena RS, Jeewon R, Jurjević Ž, Korsten L, Lamprecht SC, Lombard L, Maharachchikumbura SSN, Polizzi G, Rajeshkumar KC, Salgado-Salazar C, Shang Q-J, Shivas RG, Summerbell RC, Sun GY, Swart WJ, Tan YP, Vizzini A, Xia JW, Zare R, González CD, Iturriaga T, Savary O, Coton M, Coton E, Jany J-L, Liu C, Zeng Z-Q, Zhuang W-Y, Yu Z-H, Thines M (2022). Fusarium and allied fusarioid taxa (FUSA). 1. Fungal Systematics and Evolution 9: 161-200. doi: 10.3114/fuse.2022.09.08.

Fusarium Keratitis in Taiwan: Molecular Identification, Antifungal Susceptibilities, and Clinical Features.

We performed molecular identification and antifungal susceptibilities of pathogens and investigated clinical features of 43 culture-proven Fusarium keratitis cases from 2015–2020 in Taiwan. The pathogens were identified by sequencing of their internal transcribed spacer regions of ribosomal DNA and translation elongation factor 1α gene; their antifungal susceptibilities (to seven agents) were determined by broth microdilution method. We also collected clinical data to compare the drug susceptibilities and clinical features of Fusarium solani species complex (FSSC) isolates with those of other Fusarium species complexes (non-FSSC). The FSSC accounted for 76.7% pathogens, among which F. falciforme (32.6%) and F. keratoplasticum (27.9%) were the most common species. Among clinically used antifungal agents, amphotericin B registered the lowest minimal inhibitory concentration (MIC), and the new azoles efinaconazole, lanoconazole and luliconazole, demonstrated even lower MICs against Fusarium species. The MICs of natamycin, voriconazole, chlorhexidine, lanoconazole, and luliconazole were higher for the FSSC than the non-FSSC, but no significant differences were noted in clinical outcomes, including corneal perforation and final visual acuity. In Taiwan, the FSSC was the most common complex in Fusarium keratitis; its MICs for five tested antifungal agents were higher than those of non-FSSC, but the clinical outcomes did not differ significantly.

Current Classification and Diversity of Fusarium Species Complex, the Causal Pathogen of Fusarium Wilt Disease of Banana in Malaysia

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.

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.

Effect and Compatibility of Phosphite with Trichoderma sp. Isolates in the Control of the Fusarium Species Complex Causing Pokkah Boeng in Sugarcane

Sugarcane, a highly productive crop, is frequently challenged by different biotic agents, such as the pokkah boeng disease that can cause drastic yield losses of up to 40%. This airborne fungal disease is caused by various Fusarium species integrated into a complex. Integrating novel compounds and biological control agents is of paramount importance to cope with these fungi in sustainable systems. In this study, we aimed to evaluate the effect and compatibility of phosphite (Phi) and Trichoderma sp. in the control of Fusarium sp., in vitro and in planta. Using in vitro tests, we evaluated the effects of Phi (0, 500, 1000, 2000, 4000, and 8000 µg mL−1) and the compatibility of Phi + Trichoderma (isolates Taz 001, 013, and 016) on the pathogen complex. Using in planta tests, we evaluated the compatibility of Phi + Trichoderma (Taz-016) in the control of Fusarium in sugarcane plants under greenhouse conditions. A synergistic effect of Phi + Trichoderma was observed in vitro on the control of the pathogen, especially when combining 1000 µg mL−1 + Trichoderma Taz-016. In the in planta trial, combining 4000 µg mL−1 Phi + Trichoderma Taz-016 showed the best control of Fusarium infection, improving plant height, culm length and leaf dry weight.

English

Abstract Eroded swimmeret syndrome (ESS) was first described in 2014 from Swedish signal crayfish (Pacifastacus leniusculus (Dana)), and later also from Finland, with gross symptoms and disease agent candidates identified and described by 2015. The ESS was first discovered affecting alien signal crayfish in Fennoscandia. The ESS is caused by a multiple infection involving Aphanomyces astaci (Schikora) and Fusarium species complex (SC). The ESS symptoms include first melanised spots in swimmerets, then partial swimmeret erosion and finally loss of a swimmeret. There could be a total loss of all swimmerets in the most severe cases. Both females and males can be affected by the ESS. In females, the ESS lowers reproductive success while in males the ESS often causes erosion of the gonopods and thus possible partial failure in mating. The ESS is more frequent among mature females that have reproduced once compared to immature females or those that are mature but have not yet reproduced. The proportion of females with ESS has ranged from 10 to 50% among Lake Saimaa signal crayfish in Finland and in a wider survey from Sweden the range was from 0 to 38%. Among Lake Saimaa male signal crayfish, the ESS proportion has been less than 10%, while it was only 0.6% in the Swedish data. The ESS has also been observed among alien signal crayfish in Switzerland. There are recent observations of ESS affecting narrow-clawed crayfish, Pontastacus leptodactylus (Eschscholtz), in Croatia and Romania (i.e., among native European crayfish stocks). Here, we summarise current knowledge about the ESS and speculate on a few potentially crucial impacts of this syndrome.

High-Quality Genome Sequence Resource for Fusarium andiyazi Causing Pokkah Boeng Disease of Sugarcane in China

Sugarcane pokkah boeng disease (PBD) is emerging as a prevalent foliar disease in China. This airborne disease is caused by the Fusarium species complex. To investigate the diversity and evolution of Fusarium spp., we performed whole-genome sequencing of Fusarium andiyazi YN28 using a combination of Oxford Nanopore and Illumina technology. The F. andiyazi YN28 genome was sequenced, assembled, and annotated. A high-quality genome was assembled into 24 contigs with an N50 of 2.80 Mb. The genome assembly generated a total size of 44.1 Mb with a GC content of 47.64%. In total, 15,508 genes were predicted, including 794 genes related to the carbohydrate-active enzymes, 397 noncoding RNA, 155 genes associated with transporter classification, 4,550 genes linked to pathogen–host interactions, and 269 genes involved in effector proteins. Collectively, our results will provide insight into the host–pathogen interactions and will facilitate the breeding of new varieties of sugarcane resistant to PBD. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Maize landrace rhizospheric fungi with biocontrol potential against four different Fusarium species complexes

ABSTRACT Maize is an important crop worldwide having vital nutritional, medicinal, and economic significance. It is vulnerable to a broad spectrum of emerging infections and diseases caused by Fusarium species which are collectively termed fusariosis. The negative consequences of fusariosis can stimulate a considerable economic loss in the food chain. With this context, this study evaluated the biological control potential of 127 fungal strains that were sampled from the rhizosphere of five different Mexican maize landraces. Results showed that the strain Trichoderma sp. CM-CNRG 444 was able to inihbit the growth of maize-pathogenic strains of Fusarium fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes by colonisation and mycoparasitism on dual culture assays. The colonisation of Trichoderma sp. CM-CNRG 444 in seeds (42.5%), roots (67.5%), and crown tissue (75.5%) during maize germination reduces the tissues rot of Fusarium strains by 50%–100%. Additionally, plants co-inoculated with Trichoderma sp. CM-CNRG 444 and Fusarium strains were statistically similar to the control plants in the number of leaves, root system, stem length, and biomass accumulation. It is concluded that the fungal strain Trichoderma sp. CM-CNRG 444 protects maize seed germination, seedlings and plants development against fusariosis. Based on the findings, Trichoderma sp. CM-CNRG 444 can be used to develop an agent to control fusariosis in maize crop.

Pathogenic Fusarium species complexes associated to seeds of indigenous Brazilian forest tree Aspidosperma polyneuron

‘Peroba rosa’ (Aspidosperma polyneuron Muell. Arg.) is a forest species native to Brazil, which is threatened of extinction due to intense predatory exploitation. Knowing the physiological and sanitary aspects of the seeds or seedlings of native species is essential to determine the viability of the establishment of seedlings and natural regeneration. In tropical regions such as Brazil, the susceptibility of phytopathogens in native forest species is still poorly understood. In this work, we report for the first time Fusarium species associated with pathogenicity in Aspidosperma polyneuron. We identified a diverse group of crop pathogens Fusarium species - F. solani, F. oxysporum, F. verticillioides, F. equiseti, F. fujikuroi, F. pseudocircinatum and F. subglutinans from seeds, able to cause darkening of the leaf limb of inoculated seedlings. These results provide valuable information on the pathogenic association of Fusarium with an indigenous forest tree and possible risks these fungi might pose to the forest species.

Effect of Single and Combined Inoculations of Potato Plants with Four Fusarium Species on Wilt Severity, Plant Growth, and Production

Potato (Solanum tuberosum L.) Fusarium wilt is an increasingly serious disease in many potato-growing regions worldwide and notably in Tunisia. Fusarium sambucinum, F. oxysporum, F. solani, and F. graminearum are the main causal agents with F. oxysporum being the most aggressive on plants. Co-infection with this Fusarium species complex is frequently observed. Cultivar responses to different pathogen mixtures can give additional information on the relative aggressiveness of the different complexes. This study may lead to a better understanding of how interactions between the four Fusarium species may affect disease incidence and severity. Interactions between these Fusarium species was evaluated using single and combined inoculations (15 different Fusraium inocula) onto potato the two cultivars Spunta and Oceania. The tested inocula were evaluated for their effects on leaf yellowing and necrosis, vascular discoloration severity, potato growth and production. Necrosis severity noted 75 days post-planting induced by three different inocula C2-1 (F. sambucinum + F. solani), C2-2 (F. solani + F. oxysporum), and C3-3 (F. sambuinum+F. oxysporum +F. graminearum) were found to be the highly aggressive inoculation treatments. Overall, all mixed inocula including F. sambucinum showed increased aggressiveness levels. The two cultivars exhibited differential response to the different tested Fusarium mixtures and behaved in the majority as sensitive to moderately sensitive to C1-1, C1- 4, C2-1, C2-2, C2-3, C2-4, C2-5, C2-6, C3-1, C3-3, C3-4 and C4 treatments. This study clearly demonstrated that Fusarium wilt of potato is expected to be more severe when more than one Fusarium species is present. The relative predominance of F. sambucinum may reflect its competitive potential in mixture and its significant involvement in potato Fusarium wilt severity.

Fusarium Species and Fusarium oxysporum Species Complex Genotypes Associated With Yam Wilt in South-Central China.

Chinese yam (Dioscorea polystachya Thunb.) is an important root crop. Wilt caused by Fusarium is among the most important emerging diseases on yams. However, there is currently limited information on the molecular epidemiology of Fusarium causing yam wilt. Here, we investigated wilted yam samples from six regions in South-Central China. A total of 117 Fusarium isolates were obtained from diseased tissues of 37 wilted yam plants. These yam plants belonged to two varieties characterized by white and purple fleshy tubers, respectively. Analyses of ef1-α sequences identified that these 117 Fusarium isolates belonged to 11 putative species, with F. aff. commune being the most common (31.6%), followed by F. aff. cugenangense (29.1%), a potential undescribed species Fusarium aff. sp. (11.1%), F. aff. gossypinum (9.4%), F. aff. fujikuroi (8.5%), F. aff. nirenbergiae (6%), and one isolate each (0.85%) of F. aff. asiaticum, F. aff. curvatum, F. aff. odoratissimum, F. aff. solani, and F. aff. verticillioides. Six of these species were recently described as new species within the Fusarium oxysporum species complex (FOSC). Interestingly, 18 of the 37 yam plants were infected by two or more Fusarium species each and there was evidence for differential Fusarium species distributions based on geographic location and/or yam host variety. Multilocus microsatellite genotyping of the 67 FOSC isolates revealed that isolates of the same species from the same diseased plants often belonged to different genotypes. Interestingly, several FOSC microsatellite genotypes were shared among distinct geographic regions, consistent with long-distance dispersal. However, population genetic analyses revealed significant contributions of geographic separation to the overall genetic variation of FOSC with several pairs of geographic populations showing significant genetic differentiations, consistent with differential geographic distribution of the species within FOSC. The implications of our results to the managements of Fusarium wilt in yams were discussed.

Fusarium infections: Epidemiological aspects over 10 years in a university hospital in France

BackgroundFusarium is an environmental mold that causes deep or superficial mycosis in immunocompromised or immunocompetent patients respectively. MethodsThis epidemiological study evaluated the frequency of Fusarium infections in our university hospital center in France over a decade from 2007 to 2016 and its representativeness in the main clinical infections. ResultsA total of 715 Fusarium sp. were isolated from various sampling sites. Fusarium was detected in 0.47% of blood cultures, 31.1% of ophthalmic samples, and 8.48% of nail samples. The frequency of Fusarium infections was stable over this decade. ConclusionsThe main Fusarium species complexes recorded in this study were Fusarium oxysporum species complex and Fusarium solani species complex, indicating the importance of Fusarium as a fungal agent that should be considered in clinical practice. A focus on invasive fusarioses shows that they all occur in hematology patients.