Fusarium species and mycotoxins associated with oat in southwestern Ontario, Canada

2010 ◽  
Vol 90 (2) ◽  
pp. 211-216 ◽  
Author(s):  
L. Tamburic-Ilincic

Fusarium graminearum Schwabe [teleomorph: Gibberella zeae Schwein. Petch] is the predominant Fusarium species pathogenic to wheat, barley and corn in Ontario and produces the mycotoxin deoxynivalenol (DON) in grain. The first objective of this study was to determine the Fusarium spp. and mycotoxin concentrations (DON, HT-2, and T-2) from commercial oat (Avena sativa L.) fields grown in the same area as wheat, corn and barley in Ontario. The second objective was to measure DON level across cultivars grown in the Ontario Performance Trial (OPT) after spray-inoculation with F. graminearum. Fusarium sporotrichioides, F. graminearum and F. poae were the predominant species identified in oat. The highest level of DON in commercial oat fields were 0.3, 0.1, 0.2 and 1.2 ppm in 2005, 2006, 2007 and 2008, respectively. The highest concentrations of HT-2, and T-2 in 2006 were 0.5 and 0.2 ppm, respectively, whereas the levels in 2007 were both under 0.2 ppm. The relatively low level of DON in commercial oat fields confirmed that oat is in general less affected with F. graminearum than other cereals. However, this study supports the importance of monitoring Fusarium spp. and concentrations of mycotoxins in oat in Ontario, especially during growing conditions, as experienced in 2008, which favored Fusarium infection and DON accumulation. Differences in percent of Fusarium spp. infected kernels and DON level (ppm) were identified amongst the cultivars in the OPT in naturally infected oat samples and after inoculation, respectively. Key words: Oat, Fusarium spp., mycotoxins

2021 ◽  
Vol 22 (24) ◽  
pp. 13542
Author(s):  
Kosuke Matsui ◽  
Hirone Takeda ◽  
Koki Shinkai ◽  
Takao Kakinuma ◽  
Yoshiaki Koizumi ◽  
...  

The t-type trichothecene producers Fusarium sporotrichioides and Fusarium graminearum protect themselves against their own mycotoxins by acetylating the C-3 hydroxy group with Tri101p acetylase. To understand the mechanism by which they deal with exogenously added d-type trichothecenes, the Δtri5 mutants expressing all but the first trichothecene pathway enzymes were fed with trichodermol (TDmol), trichothecolone (TCC), 8-deoxytrichothecin, and trichothecin. LC-MS/MS and NMR analyses showed that these C-3 unoxygenated trichothecenes were conjugated with glucose at C-4 by α-glucosidic linkage. As t-type trichothecenes are readily incorporated into the biosynthetic pathway following the C-3 acetylation, the mycotoxins were fed to the ΔFgtri5ΔFgtri101 mutant to examine their fate. LC-MS/MS and NMR analyses demonstrated that the mutant conjugated glucose at C-4 of HT-2 toxin (HT-2) by α-glucosidic linkage, while the ΔFgtri5 mutant metabolized HT-2 to 3-acetyl HT-2 toxin and T-2 toxin. The 4-O-glucosylation of exogenously added t-type trichothecenes appears to be a general response of the ΔFgtri5ΔFgtri101 mutant, as nivalenol and its acetylated derivatives appeared to be conjugated with hexose to some extent. The toxicities of 4-O-glucosides of TDmol, TCC, and HT-2 were much weaker than their corresponding aglycons, suggesting that 4-O-glucosylation serves as a phase II xenobiotic metabolism for t-type trichothecene producers.


1990 ◽  
Vol 70 (4) ◽  
pp. 1057-1069 ◽  
Author(s):  
R. M. CLEAR ◽  
S. K. PATRICK

The Fusarium spp. associated with samples of wheat seed containing tombstone kernels were identified for 454 samples collected in 1986 and 1987, representing six wheat classes from three provinces. The results indicate that the frequencies and distribution of the 13 species isolated were influenced by geographic location, growing conditions and wheat class. In 1986 and 1987, F. graminearum infected the most seeds and samples of Ontario-grown wheats. It was also the most frequently recovered species from Manitoba wheats in 1986, but was absent from the Saskatchewan wheats. In 1987, F. avenaceum was isolated from the greatest percentage of seeds from Manitoba and Saskatchewan. The greatest percentage of Manitoba samples in 1986 and 1987 were infected by F. sporotrichioides whereas F. acuminatum infected the most Saskatchewan samples. Only F. graminearum infected more than 7% of the seeds of any sample of Canada Western Red Spring, Canada Prairie Spring, Canada Eastern White Winter, Canada Eastern Red Winter, or Canada Eastern Red Spring class of wheat (to a maximum of 52%), whereas five species (F. acuminatum, F. avenaceum, F. equiseti, F. poae, and F. sporotrichioides) exceeded that level in one or more samples of the Canada Western Amber Durum class. The other seven Fusarium spp. (F. compactum, F. crookwellense, F. culmorum, F. proliferatum, F. oxysporum, F. pallidoroseum, and F. subglutinans) combined accounted for <5% of isolates. Overall, the lowest frequency of Fusarium spp. was found in the Canada Western Red Spring class of wheats, and the highest in the Canada Western Amber Durum class.Key words: Fusarium, wheat, disease, graminearum, avenaceum, scab


2009 ◽  
Vol 89 (1) ◽  
pp. 103-106 ◽  
Author(s):  
L. Tamburic-Ilincic ◽  
A. W. Schaafsma

Gibberella zeae, Fusarium verticillioides and F. subglutinans are the most important causes of Fusarium stalk rot in corn (Zea mays L.). Gibberella zeae also causes fusarium head blight in wheat (Triticum aestivum L.) and gibberella ear rot in corn. The objectives of this study were to investigate prevalence of Fusarium species in the stalks of seed corn over time and to investigate the influence of sampling time and internode position on Fusarium spp. and G. zeae, particularly. Fusarium subglutinans and G. zeae were the most frequently recovered species from asymptomatic host tissue and from pink discoloration on stalks, respectively. More G. zeae was isolated from the basal internode of stalks than from the higher ones closer to harvest time. Other species isolated from seed corn stalks over time included F. verticillioides, F. oxysporum, F. sporotrichioides and F. equiseti. A similar spectrum of Fusarium species was identified from corn ears and from winter wheat across southwestern Ontario. Key words: Zea mays L., Fusarium spp.


2015 ◽  
Vol 30 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Sonja Tancic ◽  
Slavica Stankovic ◽  
Jelena Levic ◽  
Vesna Krnjaja

A total of 39 Fusarium graminearum, F. sporotrichioides, F. semitectum and F. equiseti isolates, originating from wheat and maize samples collected at 10 locations in Serbia, were analyzed by ELISA method for their potential of deoxynivalenol (DON) and zearalenone (ZEA) production under optimal laboratory conditions. Fusarium graminearum isolates with the highest intraspecies variability were the best producers of both deoxynivalenol and zearalenone. In contrast, F. equiseti isolates were the weakest producers of these two toxins. Considering the plant origin of the isolates, wheat-originating F. sporotrichioides isolates were better deoxynivalenol producers, while the maize-originating isolates produced more zearalenone. There was no clear difference in ZEA production between wheat- and maizeoriginating isolates of F. graminearum, while higher average DON concentrations were produced by F. graminearum wheat-originating isolates. Negative correlation was detected between the production of deoxynivalenol and zearalenone by various Fusarium spp.


2012 ◽  
Author(s):  
◽  
Gisele Kikot

La Fusariosis de la espiga de trigo (FET) es una compleja enfermedad fúngica que afecta tanto al rendimiento y calidad de la producción granaria como a la salud por acción de la micotoxina asociada. Diversas especies de Fusarium pueden relacionarse con la FET. La distribución y predominancia de estos patógenos están determinadas en gran parte por factores climáticos como la temperatura y la humedad. En Argentina, el agente fúngico dominante asociado a la FET es Fusarium graminearum (Schwabe) anamorfo de Gibberella zeae (Schw.) Petch. La enfermedad es el resultado de la acción individual o combinada de diferentes mecanismos de patogénesis, como la producción y liberación de enzimas extracelulares que degradan los principales constituyentes de la pared celular y permiten la colonización de los tejidos. Una vez establecida la infección se produce la liberación de micotoxinas que interfieren con el metabolismo o que afectan la integridad estructural de la célula hospedera o bien sus procesos fisiológicos, lo cual da como resultado pérdida en el rendimiento y calidad de las cosechas. La investigación se basó en el aislamiento e identificación de aislados de Fusarium spp. asociados con FET a partir de muestras de trigo provenientes de 15 localidades distribuidas en las provincias de Buenos Aires, Entre Ríos, Santa Fe y Córdoba durante las campañas trigueras 2006 y 2007. Se analizó la diversidad genética entre aislamientos de F. graminearum con marcadores moleculares ISSR y RFLP, así como la diversidad química y estructural mediante espectroscopía vibracional FT-IR. Determinada la distancia genética entre aislamientos, se analizó la agresividad de los mismos sobre trigo en invernáculo a partir del análisis de diversas variables patométricas. Además, se detectaron y caracterizaron actividades enzimáticas relacionadas con el proceso de colonización y daño sobre los granos, las cuales serían responsables de cambios estructurales y de composición de los mismos. Se seleccionó un aislamiento de F. graminearum con elevada actividad enzimática poligalacturonasa, como estimativo de agresividad, para evaluar resistencia a la penetración del patógeno en la espiga. La patogenicidad se evaluó sobre diversos genotipos de trigo a campo bajo condiciones de temperatura y humedad parcialmente controladas. Este tipo de evaluación permite identificar nuevas fuentes de resistencia.


2000 ◽  
Vol 78 (4) ◽  
pp. 497-505 ◽  
Author(s):  
W GD Fernando ◽  
J D Miller ◽  
W L Seaman ◽  
K Seifert ◽  
T C Paulitz

Spores were sampled during 2 years over wheat plots at Ottawa, Ontario. Plots were treated with corn colonized with Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum Schwabe). In 1994, viable spores were sampled with four Burkard high-throughput jet samplers. Gibberella zeae ascospores were recovered mostly at night and showed four main release events during the 20-day sampling period, 1-3 days after rain events. Highest density of G. zeae spores (1500 spores/m3) were sampled 1.5 m away from the inoculum source, with fewer spores 5 m away. Recovery of otherFusarium species was sporadic. For all species, there were no statistical differences among the daily sampling times, although for most species, morning counts were the lowest. Other Fusarium species detected, in decreasing order of spore density, were F. crookwellense, F. sporotrichioides, F. moniliforme, F. equiseti, F. subglutinans, and F. culmorum. Most spore release events did not correlate with rainfall events. In 1995, a Burkard continuous 7-day spore sampler was used to investigate the release of ascospores and macroconidia of G. zeae. Ascospores, but not macroconidia, showed a daily periodicity. Daily average densities of macroconidia were an order of magnitude less than ascospores. Ascospore release was correlated with rainfall events and the time of day.Key words: spore sampling,Gibberella zeae, Fusarium graminearum, Fusarium sp. ascospores, macroconidia.


Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 438
Author(s):  
Mary E. Ridout ◽  
Bruce Godfrey ◽  
George Newcombe

Fusarium species coexist as toxigenic, systemic pathogens in sweet corn seed production in southwestern Idaho, USA. We hypothesized that fungal antagonists of seedborne Fusarium would differentially alter production of Fusarium mycotoxins directly and/or systemically. We challenged the Fusarium complex by in vitro antagonism trials and in situ silk and seed inoculations with fungal antagonists. Fungal antagonists reduced growth and sporulation of Fusarium species in vitro from 40.5% to as much as 100%. Pichia membranifaciens and Penicillium griseolum reduced fumonisin production by F. verticillioides by 73% and 49%, respectively, while P. membranifaciens and a novel Penicillium sp. (WPT) reduced fumonisins by F. proliferatum 56% and 78%, respectively. In situ, pre-planting inoculation of seeds with Penicillium WPT systemically increased fumonisins in the resulting crop. Morchella snyderi applied to silks of an F1 cross systemically reduced deoxynivalenol by 47% in mature seeds of the F2. Antagonists failed to suppress Fusarium in mature kernels following silk inoculations, although the ratio of F. verticillioides to total Fusarium double with some inoculants. Fusarium mycotoxin concentrations in sweet corn seed change systemically, as well as locally, in response to the presence of fungal antagonists, although in Fusarium presence in situ was not changed.


Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 724-730 ◽  
Author(s):  
S. A. Pereyra ◽  
R. Dill-Macky ◽  
A. L. Sims

Survival and inoculum production of Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum (Schwabe)), the causal agent of Fusarium head blight of wheat and barley, was related to the rate of wheat (Triticum aestivum L.) residue decomposition. Infested wheat residue, comprising intact nodes, internodes, and leaf sheaths, was placed in fiberglass mesh bags on the soil surface and at 7.5- to 10-cm and 15- to 20-cm depths in chisel-plowed plots and 15 to 20 cm deep in moldboard-plowed plots in October 1997. Residue was sampled monthly from April through November during 1998 and every 2 months through April to October 1999. Buried residue decomposed faster than residue placed on the soil surface. Less than 2% of the dry-matter residue remained in buried treatments after 24 months in the field, while 25% of the residue remained in the soil-surface treatment. Survival of G. zeae on node tissues was inversely related to the residue decomposition rate. Surface residue provided a substrate for G. zeae for a longer period of time than buried residue. Twenty-four months after the initiation of the trial, the level of colonization of nodes in buried residue was half the level of colonization of residue on the soil surface. Colonization of node tissues by G. zeae decreased over time, but increased for other Fusarium spp. Ascospores of G. zeae were still produced on residue pieces after 23 months, and these spores were capable of inducing disease. Data from this research may assist in developing effective management strategies for residues infested with G. zeae.


2010 ◽  
Vol 16 (3) ◽  
pp. 266-276 ◽  
Author(s):  
G. Cano-Sancho ◽  
S. Marin ◽  
A.J. Ramos ◽  
V. Sanchis

Fusarium species are probably the most prevalent toxin-producing fungi of the northern temperate regions and are commonly found on cereals grown in the temperate regions of America, Europe and Asia. Among the toxins formed by Fusarium we find trichothecenes of the A-type or B-type, zearalenone, fumonisins or nivalenol. The current exposure assessment consists of the qualitative and/or quantitative evaluation based on the knowledge of the mycotoxin occurrence in the food and the dietary habits of the population. This process permits quantifying the mycotoxin dietary intake through deterministic or probabilistic methods. Although these methods are suitable to assess the exposure of populations to contaminants and to identify risk groups, they are not recommended to evaluate the individual exposition, due to a low accuracy and sensitivity. On the contrary, the use of biochemical indicators has been proposed as a suitable method to assess individual exposure to contaminants. In this work, several techniques to biomonitor the exposure to fumonisins, deoxynivalenol, zearalenone or T-2 toxin have been reviewed.


2003 ◽  
Vol 33 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Edivan Panisson ◽  
Walter Boller ◽  
Erlei Melo Reis ◽  
Laércio Hoffmann

Durante muitos anos, a giberela, causada pelo fungo Gibberella zeae (anamorfo Fusarium graminearum), foi considerada de importância secundária no sul do Brasil. O aumento da intensidade e da freqüência de ocorrência, tornou a giberela uma das doenças de maior importância na cultura do trigo. A giberela é uma doença de infecção floral e mesmo os fungicidas sistêmicos recomendados apresentam apenas efeito protetor das anteras. Os objetivos do presente trabalho foram avaliar a eficiência de controle e os efeitos nos grãos colhidos, de dois tipos de pontas de pulverização (leque e duplo leque), diferentes arranjos dos bicos na barra de aplicação e dois volumes de calda. A desuniformidade da antese aparece como um dos principais fatores envolvidos com a baixa eficiência dos fungicidas. Nos experimentos, realizados no ano 2000, a aplicação dos tratamentos reduziu significativamente a incidência, o número de espiguetas gibereladas e a severidade da doença, aumentando o rendimento de grãos. As pontas de pulverização, seus arranjos na barra e os volumes de calda utilizados comportaram-se de maneira semelhante em todas as variáveis avaliadas. O incremento no rendimento de grãos, obtido em relação à testemunha, sugere que se deve recomendar a aplicação de fungicidas para o controle da giberela, utilizando pontas que geram gotas finas a médias com volume de calda de 200 L.ha-1.


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