Distribution Of Fusarium Species Research Articles

Fusarium Species Shifts in Maize Grain as a Response to Climatic Changes in Poland

Maize, along with wheat and rice, is the most important crop for food security. Ear rots caused by Fusarium species are among the most important diseases of maize. The distribution of Fusarium species provides essential epidemiological information for disease management. The effect of weather conditions, climate change and geographic localization on the Fusarium population in Poland was evaluated between 2015 and 2018. Grain samples (n = 233) were collected from hybrids at 16 locations (L1–L16). The differences in altitude between locations ranged from 39 to 243 m above sea level, longitude varied between 15°55′ and 23°12′ E, and latitude spanned from 50°12′ to 54°01′ N. Isolates were identified using molecular techniques. The highest Fusarium species frequency was recorded for 2016 (30.70%) and 2017 (28.18%), and the lowest for 2018 (5.36%). F. verticillioides and F. temperatum were the most frequent. Altitude has an effect on F. vericillioides frequency: F. graminearum showed a negative correlation with both latitude and longitude. In Polish conditions, from silking to harvesting, the number of days with higher precipitation and lower temperatures is associated with an increased frequency of F. verticillioides, F. temperatum, F. graminearum and F. avenaceum. This suggests that the Fusarium presence in Poland is significantly influenced not only by climate change but also by extreme weather changes.

Effectiveness of Species- and Trichothecene-Specific Primers in Monitoring Fusarium graminearum Species Complex in Small Grain–Pea Intercropping Systems

Tracking the distribution of Fusarium species and the detection of changes in toxin production provides epidemiological information that is essential for Fusarium head blight (FHB) management. Members of Fusarium graminearum species complex (FGSC) were characterized using species and trichothecene-specific primers. Associations between members of the FGSC, cereal crop species (wheat, rye, triticale, and oat), seeding time (winter and spring), type of cultivation (monocrop and intercrop) and chemotype grouping were investigated with multiple correspondence analysis and multiple regression modeling. We found that triticale and oat were more related to isolates classified into F. graminearum s. lato than with other isolates. In contrast, wheat and rye were more associated with F. graminearum s. stricto. Cereal crop species affected the frequencies of F. graminearum s. stricto (p = 0.003) and F. graminearum s. lato (p = 0.08) and unidentified isolates with morphological characteristics like those of FGSC members (p = 0.02). The effectiveness of species-specific primers was 60.3% (Fg16F/R) and 76.2% (FgrF/FgcR), and the effectiveness of primer sets for the trichothecene genotyping of the Tri5 and Tri3 genes was 100% and 90.6%, respectively. The decrease in Fusarium-damaged kernel values in the wheat–pea intercropping system indicated that intercropping systems have the potential to control FHB.

A Nutritional Survey of Local Barley Populations Based on the Mineral Bioavailability, Fatty Acid Profile, and Geographic Distribution of Fusarium Species and the Mycotoxin Zearalenone (ZEN)

Knowledge about the extent of nutrient variability in local barley germplasm is an important prerequisite for efficient crop improvement. The present study is one of the first to assess the potential of Tunisian barley populations (named Testour, Gergis, and Enfidha) as sources of desirable traits for barley improvement and for the prevalence of Fusarium species and the mytoxin zearalenone (ZEN). Analysis of variance revealed highly significant differences between barley populations for nutrients density. The lowest phytate/zinc molar ratios were observed in Testour and Enfidha populations with 7.23 and 9.97, respectively. However, the bioavailability of iron of most barley populations (95.4%) was inhibited mainly by the high phytate content. Oleic acid (15.2–18.7%), linoleic acid (13.8–16.01%), and palmitoleic acid (4.7–14.2%) were identified as predominant fatty acid constituents in all three barley populations. Based on morphologic and molecular characterization, Fusarium graminearum and Fusarium culmorum were the predominant species that infected Testour, Gergis, and Enfidha populations. The concentration of zearalenone ranged between 0 and 140 µg kg−1. The highest levels of zearalenone, 92 μg kg−1 and 60 μg kg−1, were detected in Testour populations that were infected with F. graminearum and F. culmorum, respectively. These relatively low amounts of zearalenone in barley populations can be attributed to the Tunisian climate and the resistance of local genotypes. Testour and Enfidha barley populations could potentially be used to improve breeding programs for biofortification.

Isolation of Fusarium and identification of its toxins from tuberous root of Pseudostellaria heterophylla

Fusarium is the major pathogen of root rot of Pseudostellaria heterophylla. This study aims to explain the possible distribution of Fusarium species and the contamination of its toxin-chemotypes in tuberous root of P. heterophylla. A total of 89 strains of fungi were isolated from the tuberous root of P. heterophylla. Among them, 29 strains were identified as Fusarium by ITS2 sequence, accounting for 32.5%. They were identified as five species of F. avenaceum, F. tricinctum, F. fujikuroi, F. oxysporum, and F. graminearum based on β-Tubulin and EF-1α genes. LC-MS/MS detected 18, 1, and 5 strains able to produce ZEN, DON, and T2, which accounted for 62.1%, 3.4%, and 17.2%, respectively. Strain JK3-3 can produce ZEN, DON, and T2, while strains BH1-4-1, BH6-5, and BH16-2 can produce ZEN and T2. PCR detected six key synthase genes of Tri1, Tri7, Tri8, Tri13, PKS14, and PKS13 in strain JK3-3, which synthesized three toxins of ZEN, DON, and T2. Four key synthase genes of Tri8, Tri13, PKS14, and PKS13 were detected in strains BH1-4-1, BH6-5, and BH16-2, which were responsible for the synthesis of ZEN and T2. The results showed that the key genes of toxin biosynthesis were highly correlated with the toxins produced by Fusarium, and the biosynthesis of toxin was strictly controlled by the genetic information of the strain. This study provides a data basis for the targeted prevention and control of exo-genous mycotoxins in P. heterophylla and a possibility for the development of PCR for rapid detection of toxin contamination.

Fusarium fujikuroi Species Complex Associated With Rice, Maize, and Soybean From Jiangsu Province, China: Phylogenetic, Pathogenic, and Toxigenic Analysis.

Species belonging to the Fusarium fujikuroi species complex (FFSC) are of vital importance and are a major concern for food quantity and quality worldwide, as they not only cause serious diseases in crops but also produce various mycotoxins. To characterize the population structure and evaluate the risk of poisonous secondary metabolites, a total of 237 candidate strains were isolated from rice, maize, and soybean samples in Jiangsu Province, China. Species identification of the individual strain was accomplished by sequencing the translation elongation factor 1α gene (TEF-1α) and the fumonisin (FB) synthetic gene (FUM1). The distribution of Fusarium species among the different crops was observed. The maize seeds were dominated by F. proliferatum (teleomorph, Gibberella intermedia) and F. verticillioides (teleomorph, G. moniliformis), whereas F. fujikuroi (teleomorph, G. fujikuroi) was the most frequently isolated species from rice and soybean samples. In addition, phylogenetic analyses of these strains were performed, and the results suggested clear groups showing no obvious relationship with the origin source. FFSC species pathogenicity and toxigenicity were studied. All of the species reduced the rice seed germination rate, with no significant differences. F. fujikuroi showed two distinct patterns of influencing the length of rice seedlings, which were correlated with FBs and gibberellic acid synthesis. FBs were mainly produced by F. verticillioides and F. proliferatum. F. proliferatum and F. fujikuroi also produced moniliformin and beauvericin. The toxigenicity of F. andiyazi (teleomorph, G. andiyazi) was extremely low. Further analysis indicated that the sequence variations in TEF-1α and the differences in the expression levels of the toxin synthesis genes were associated with the diversity of secondary metabolites in F. fujikuroi strains. These findings provide insight into the population-level characterization of the FFSC and might be helpful in the development of strategies for the management of diseases and mycotoxins.

Survey for toxigenicFusarium species on maize kernels in China

Maize is currently the most important crop in China. A major concern in maize production is maize ear rot caused byFusarium spp., which results in yield losses, reduction of seed quality and the accumulation of mycotoxins in the harvested grains. To identify the importance of the differentFusarium species in maize infection, we performed a comprehensive survey on 9,000 asymptomatic and randomly collected maize kernels. Seeds were collected from 12 different provinces covering all major maize growing areas in China and included five maize varieties. In total 1,022Fusarium isolates were retrieved that were identified based on morphological characteristics, by species specific diagnostic PCRs and by EF1-α gene sequencing. Eight different species were identified:Fusarium verticillioides (75.34%),Fusarium graminearum (8.32%),Fusarium proliferatum (7.14%),Fusarium subglutinans (4.11%),Fusarium meridionale (1.57%),Fusarium oxysporum (1.37%),Fusarium semitectum (1.17%), andFusarium asiaticum (0.98%). The distribution ofFusarium species was found to be different in different regions with the largest diversity observed in Hubei province, where all eightFusarium species were isolated. Genetic chemotyping within theF. graminearum species complex indicated that all of the 85F. graminearum isolates showed the 15-acetyldeoxynivalenol chemotype, whereas allF. asiaticum (n=10) andF. meridionale (n=16) isolates had the nivalenol chemotype even when isolated from the same maize field. To our knowledge this is the largest collection ofFusarium isolates from maize and further exploitations of this collection are discussed.

Indoor Plumbing Drains Are Important Sources for Invasive Fusariosis in Patients with Hematological Disorders: Culture-Based and Metagenomic Analysis

Despite the advances in antifungal drugs, the number of invasive fusariosis (IF) has been increasing in patients with hematological disorders, especially hematopoietic stem cell transplantation (HSCT) patients. IF is still a severe infection and refractory to treat because Fusarium is naturally resistant to most of the antifungal drugs. Therefore, prior to infection, avoidance of contact with Fusarium would be critical in immunocompromised patients. However, little is known about the source of Fusarium infection. The purpose of this study is to investigate the epidemiology of IF in patients with hematological disorders in Japan and to find out the infectious source of Fusarium and the relationship between Fusarium species isolated from clinical samples and the ones from environment using culture-based and metagenomic methods. In our center, a total of 99 clinically isolated Fusarium were stored and maintained. They were obtained from hospitals in 33 prefectures in Japan. 50 and 49 strains were recovered from IF patients and superficial fusariosis (SF) patients, respectively. In this study, we analyzed 42 IF cases which developed in patients with hematological disorders. The most common underlying disease was AML (35.7%), followed by ALL (23.8%). About 60% of the patients received HSCT, and most of them became infected with Fusarium in the early phase after HSCT (within eight weeks). This result indicated that IF infection mostly occurred in indoor environments. As the next step, we performed the surveys in indoor environments such as air and plumbing drains in medical institutions and residences to figure out the source of infection. Few Fusarium species were collected from air samples. From the indoor air, we collected 142 filamentous fungi isolates. Only 2/142 strains (1.4%) were Fusarium species (Fusarium fujikuroi species complex 1, F. nisikadoi 1). In contrast, among the 72 drain port samples collected from 6 medical institutions (hematology wards, including bone marrow transplantation units, and ICU/NICU) and 15 residences, Fusarium species were positive at 26 (36.1%) sampling points. One hundred and eight filamentous fungi were isolated from the drain samples, and 29/108 isolates (27%) were Fusarium species. In details, 20 strains were Fusarium solani species complex (F. petroliphilum 7, F. keratoplasticum 4, F. sensu stricto 4, F. falciforme 1, others 4) and nine strains were Fusarium oxysporum species complex. Interestingly, the FSSC compositions of drain port samples were similar to those of IF samples from patients with hematological disorders and different from those of SF samples. In contrast, no Fusarium strains were detected in the places where the regular sink-cleaning was performed. Likewise, the samples for the metagenomic analysis were obtained in the places where the culture samples were collected. DNA extraction from samples was performed by the PowerLyzer Powersoil Kit (QIAGEN, Hilden, Germany). Fungal ITS regions were amplified with modified ITS1F and ITS2 primer set and sequenced with Illumina Miseq platform. After filtering and denoising, we were able to analyze 8 air samples and 23 drain samples (10 culture-positive samples and 13 culture-negative samples). It is also revealed that a lot of Fusarium live indoor plumbing drains but few Fusarium spp. inhabit indoor air (less than 0.1%). In summary, we investigate the epidemiology of IF in patients with hematological disorders in Japan and the distribution of Fusarium species in indoor environments. Our survey has demonstrated that a lot of Fusarium inhabits the indoor plumbing drains, not the indoor air using the culture-based and metagenomic methods. The similarity of FSSC distribution between the drain samples and causative species of IF cases indicated that the indoor plumbing drains would be potential sources of IF infection. We suggested that regular sink-cleaning was critical to prevent patients with hematological disorders from Fusarium infection. Disclosures No relevant conflicts of interest to declare.

The Prevalence and Distribution of Fusarium species in Norwegian Cereals: a Survey

In the period 1994–1996 a post-harvest survey was conducted in wheat, barley and oats to assess the occurrence and geographic distribution of Fusarium species in Norwegian cereals. The number of samples investigated was adjusted proportionally to the production of each cereal species within the regions. A total of 695 grain samples were analysed. The amount of Fusarium infection varied with cereal species and region of origin. The most frequently isolated Fusarium spp. from all samples were F. avenaceum, F. poae, F. tricinctum and F. culmorum. Other important toxigenic Fusarium spp. were F. graminearum, “powdery F. poae”, F. equiseti and F. sporotrichioides. A north-south gradient was valid for F. tricinctum, F. poae and in 1994 for “powdery F. poae”. In 1994 “powdery F. poae” was the most abundant potential producer of HT-2 and T-2 toxins in Norwegian cereals. Distribution of F. graminearum and F. culmorum demonstrated in this study, corresponded to previously reported DON-distribution, although DON seems to be produced by different species in different regions. Distribution of the isolated Fusarium species and comparison between cereals and locations are discussed.

Occurrence and distribution of Fusarium species in maize fields in New Zealand.

Fusarium populations were investigated in maize grains and their husks about six weeks before harvest in three maize fields in the Manawatu region of New Zealand. The role of litter and soil as reservoirs for these fungi was also examined. Two techniques were used to examine populations, dilution plating and direct plating. Using the dilution plating technique the highest overall populations were found in husks (mean 2.2 x 10(5)/g) and litter (mean 1.4 x 10(5)/g), while similar lower numbers of viable propagules were obtained from grain (mean 2.1 x 10(3)/g) and soil (2.8 x 10(3)/g). With this technique five Fusarium spp. were commonly isolated; F. graminearum (Gibberella zeae), F. culmorum, F. subglutinans, F. oxysporum and F. acuminatum, of which F. graminearum was the most abundant. With the direct plating technique 87% of grains were infected with Fusarium spp., with some grains being infected with more than one species. Segments from husks and litter, 70% and 43% respectively, were colonised by Fusariumr spp. F. graminearum was the most frequent species isolated from maize grain and husk segments (48.3 and 37.7% colonisation respectively). Other species, particularly F. culmorum and F. acuminatum, were also found to be common contaminants. A total of 15 Fusarium spp. was recovered from all material examined by both techniques. Cultures with characteristics resembling those of F. moniliforme were rarely observed.

Mycological evaluation of a sorghum grain of Argentina, with emphasis on the characterization of Fusarium species

Characterization of the internal mycota of sorghum grain from the Santa Fe Province of Argentina was performed, particularly for those species considered potentially toxigenic. The prevalence of these species in the grains was recorded. The distribution of Fusarium species and the percentage of colonized kernels was also recorded. Observations were made using a light field microscope and a stereomicroscope. Isolation was carried out by direct plating on potato-dextrose agar+chloramphenicol. For identification and confirmation, specific media and culturing regimes were followed according to the literature. Total fungal counts by dilution plate on dichloran-rose Bengal-chloramphenicol agar, and moisture content measures were also performed. Total fungal counts were in the range of 2·4×104–2·5×105cfu g−1. Investigation of the internal mycota revealed a prevalence of species of Fusarium, Alternaria andCurvularia , which were present first in the total of samples. The most important potentially toxigenic species belonged toFusarium, Alternaria and Penicillium, but potentially toxigenic species of Aspergillus andPhoma were also present. Species of Fusarium were F. moniliforme Sheldon, F. chlamydosporum Wollenw. & Reinking, F. semitectum Berk. & Ravenel and F. subglutinans (Woll. & Rein.) Nel., Touss. & Mar., in order of frequency of occurrence. The highest percentages of colonized kernels corresponded to the first two species. A close association was observed between F. moniliforme and A. alternata in 90% of the samples.

Occurrence and distribution ofFusariumspecies in barley and oat seed from Manitoba in 1993 and 1994

Occurrence and distribution of<i>Fusarium</i>species in barley and oat seed from Manitoba in 1993 and 1994

Fusarium and Fumonisin Occurrence in Argentinian Corn at Different Ear Maturity Stages

The distribution of Fusarium species (Liseola section) and fumonisins B 1 , B 2 , and B 3 (FB 1 , FB 2 , and FB 3 ) in corn at the field stage to harvest time has been investigated. Corn samples were obtained from the 45th day after flowering to harvest stage, with 15 day intervals. A good correlation between fungal species and fumonisin contamination was observed. In particular, fumonisin contamination was higher in samples with fungal infection represented mainly by Fusarium moniliforme and Fusarium proliferatum, two well-known producers of fumonisins. Low levels of fumonisins were detected at the first and second samplings, when mainly Fusarium subglutinans, a fumonisin nonproducer species, was recorded. The three samplings after physiological maturity showed predominant F. moniliforme and F. proliferatum infection and a considerable contamination with fumonisins. In these samples the levels of FB 1 averaged above 1 μg/g and FB 2 and FB 3 levels showed similar values but lower than FB 1 values. This is the first report of fumonisins in Argentinian corn at field stages.

The distribution ofFusarium species in soils planted to millet and sorghum in Lesotho, Nigeria and Zimbabwe

Samples from soils planted to millet and sorghum from Lesotho, Nigeria, and Zimbabwe were processed and a total of 3,291Fusarium cultures were recovered. Of these 1,296 cultures were isolated from plant debris and 1,995 cultures were recovered from soil dilutions. The most prevalent species recovered wereF. oxysporum (37%),F. equiset (30%),F. solani (14%),F. moniliforme (6%),F. compactum (5%),F. nygamai (4%), andF. chlamydosporum (2%). OtherFusarium species isolated wereF. merismoides, F. polyphialidicum, F. graminearum, F. subglutinans, F. sambucinum, F. longipes, F. semitectum, F. dimerum, F. lateritium, and a group of cultures designated as population A which resembleF. camptoceras. Fusarium equiseti was the predominant species in soil samples from Nigeria and Zimbabwe, whileF. oxysporum was the predominant species recovered from soil from Lesotho.

Distribution of Fusarium Species in Sections Roseum, Arthrosporiella, Gibbosum and Discolor Recovered from Grassland, Pasture and Pine Nursery Soils of Eastern Australia

Fusarium species in sections Roseum, Arthrosporiella, Gibbosum, and Discolor were common in grassland, pasture, and pine nursery soils of eastern Australia. The grasslands consisted of grazing land...

Studies into the occurrence of some trichothecene mycotoxins in UK home‐grown wheat and in imported wheat

AbstractA total of 199 UK home‐grown wheat samples collected over three harvests (1980–82 inclusive) and 33 imported wheat samples were analysed for the presence of seven trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon‐x, neosolaniol, diacetoxyscirpenol, HT‐2 toxin and T‐2 toxin). Analysis was performed by a gas–liquid chromatographic method and positive results greater than 0.1 mg kg−1 were confirmed by mass spectrometry. The only mycotoxin detected in any of the samples was deoxynivalenol (vomitoxin) which occurred in 32 out of 199 UK home‐grown wheats at levels ranging from 0.02 to 0.40 mg kg−1 and 23 out of 33 imported wheats at levels ranging from 0.02 to 1.32 mg kg−1. Microbiological evidence suggests that the lower incidence and levels of deoxynivalenol in UK, other EEC and Western Canadian wheat compared with Eastern Canadian and Midwest US wheat may be caused by a geographical variation in the distribution of Fusarium species.