Mycotoxins have been widely studied by many research groups but further multidisciplinary research is needed to better understand and clarify many issues. This study describes the use of ...high-performance liquid chromatography coupled with ion trap mass spectrometry (HPLC-MS) to measure T-2 toxin and its metabolites, such as HT-2 toxin, neosolaniol (NEO) and diacetoxyscirpenol (DAS), as well as masked glucosylated mycotoxins in Fusarium-infected Czech spring barley. In total, 152 spring barley samples from the 2018 harvest were analyzed by the ELISA screening method for the presence of T-2 toxin. The most contaminated samples (15), which exceeded the recommended maximum level set by the EU for the sum of T-2 and HT-2 toxin in unprocessed cereals (200 μg/kg), were analyzed by HPLC-MS/MS and microbiological testing. Isolated fungi were evaluated microscopically and identified by polymerase chain reaction (PCR) assays. The prevalence of Fusarium species in spring barley across the Czech Republic in 2018 showed a predominance of F. poae (12 barley samples) and F. tricinctum (9 barley samples). Other strains (F. sporotrichioides and F. langsethiae) were present at a lower frequency, in 1 and 2 samples, respectively. The average concentration of T-2 plus HT-2 toxin was 107.7 μg/kg, while NEO and DAS were found in a few samples at values close to their limit of quantification. HT-2 glucoside was identified in all samples.
•In total 152 barley samples were analyzed by ELISA for the presence of T2 toxin.•Fifteen of them exceeded the recommended maximum level set by the EU for the sum of T-2 and HT-2 toxin.•T-2 toxin and its metabolites including masked forms were identified and quantified by HPLC-MS/MS.•Cross-reactivity and overestimation of ELISA results compared to HPLC-MS/MS was confirmed.•In the most contaminated samples Fusarium tricinctum and Fusarium poae were predominant.
Wheat root diseases can seriously reduce yields and quality of wheat. 1,2,4-Triazole benzoyl arylamine derivatives previously showed good activities against some wheat root fungal pathogens. To ...further systematically disclose the structure–activity relationship, a series of benzoyl arylamines were designed and prepared. Their structures were characterized and fungicidal activities against Gaeumannomyces graminis var. tritici and Fusarium graminearum were evaluated. The results indicated that the structure of the N-heterocyclic group and the substituted group and their position on the benzamide scaffold had an important influence on the activities, as predicted. Finally, compound 18f was found to show excellent activities against G. graminis var. tritici, F. graminearum, Fusarium culmorum, Fusarium pseudograminearum, and Fusarium moniliforme with half-maximum effective concentrations of 0.002, 0.093, 0.011, 0.881, and 0.287 μg/mL, respectively. These results proposed that compound 18f deserved serious consideration as a novel fungicide candidate for the control of wheat root diseases.
Relevance
. Tomato root rot is a complex disease caused by a variety of soil-borne fungal pathogens, among which Fusarium oxysporum,
F. solani
and
F. gibbosum
occur with the greatest frequency in the ...conditions of the Republic of Moldova. The originality of the work consists in identifying the differentiated influence of pathogens of
Fusarium
root rot and temperature on the variability and heritability of the organs of growth and development of tomato plants.
Material and methods
. Two varieties and 3 lines of tomatoes with good economically valuable characteristics were used as material for the study. To test the response of plants to pathogens of fusarium root rot, we used culture filtrates of 6 –
F. oxysporum
isolates, 6 –
F. solani
, and 4 –
F. gibbosum
, prepared in a standard liquid Czapek medium. The plants were grown at the optimum temperature (23...24°C) and with alternating temperatures of 23...24°C and 10...11°C for two days each. Seed germination and root length were used as indicators of growth and development. The genetic parameters of the variability and heritability of the studied traits were studied.
Results
. An analysis of the reaction based on seeds germination and root growth showed its significant differentiation in the
tomato
genotype x type of fungus x isolate of the fungus x temperature
system. A factor analysis of the interaction of the
tomato genotype x Fusarium fungus
revealed a significant role of the plant genotype in response to the pathogens. A significant effect of Fusarium fungi and temperature on the genetic and phenotypic variance of signs of growth and development of tomato plants, heritability in a broad sense, genotypic and phenotypic coefficient of variation, and genetic progress have been established. It is concluded that it is advisable to use the reaction of signs of growth and development of tomato to
Fusarium
pathogens in order to identify genotypes with good inheritance of the resistance trait.
In this study, twenty of the most common
species were molecularly characterized and inoculated on potato dextrose agar (PDA), rice and maize medium, where thirty three targeted mycotoxins, which ...might be the secondary metabolites of the identified fungal species, were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Statistical analysis was performed with principal component analysis (PCA) to characterize the mycotoxin profiles for the twenty fungi, suggesting that these fungi species could be discriminated and divided into three groups as follows. Group I, the fusaric acid producers, were defined into two subgroups, namely subgroup I as producers of fusaric acid and fumonisins, comprising of
,
,
and
, and subgroup II considered to only produce fusaric acid, including
,
,
,
,
,
,
,
,
. Group II, as type A trichothecenes producers, included
,
,
, while Group III were found to mainly produce type B trichothecenes, comprising of
,
,
and
. A comprehensive picture, which presents the mycotoxin-producing patterns by the selected fungal species in various matrices, is obtained for the first time, and thus from an application point of view, provides key information to explore mycotoxigenic potentials of
species and forecast the
infestation/mycotoxins contamination.
Fusarium head blight (FHB) is a major disease on wheat crop leading to significant yield losses and poor quality of infected grains worldwide. From a breeder's point of view, a simple and reliable ...test for assessing this disease would enhance our capacity in identifying wheat resistance sources and highly pathogenic isolates. To achieve this objective, a test involving the inoculation of a detached head (DHT) maintained in vitro was used to determine the reaction of six durum and bread wheat cultivars to disease and pathogenicity of four Fusarium species. The estimation of disease incidence and disease severity detected using spray and point inoculation on detached wheat heads, respectively, enabled discrimination among wheat cultivars differing in their susceptibility to the pathogen and 16 FHB isolates of contrasting pathogenicity. Significant correlations were found between in vitro DHT values in seedlings and adult plants, highlighting that this testing procedure was reliable. The established assay using in vitro DHT in this first in-depth report enables a simple, fast and reliable screening of the susceptibility of durum and bread wheat to FHB pathogens and pathogenicity of diverse Fusarium species and should be useful for many types of studies on this disease.
Wheat grains collected in three regions of Russia-Volga, Ural, and West Siberia-were analyzed for triangulation of methods in analysis of toxigenic
species. The presence of fungi and quantitative ...content of their biomass were detected by using various analytical methods, including a mycological and immunochemical methods, and quantitative PCR. Additionally, an enzyme-linked immunosorbent assay and high-performance liquid chromatography with tandem mass spectrometry were applied for determination of mycotoxins. Regional differences were found regarding the contamination of wheat grain by
fungi and their toxins. The most important observation was the detection of
in the Ural and West Siberian regions, where this pathogen had not been found previously. A maximum damaged grains by
and
was found in the grain samples from West Siberia. The DNA of
was detected in 19.2% and DNA of
was found in 84.1% of the analyzed grain samples. The amount of
antigens in the grain samples from the West Siberian region was 7-8 times higher than in the grain samples from the other two regions. Significant contamination of the grain with deoxynivalenol and T-2/HT-2 toxins (maximum contents were 2239 ppb and 199 ppb, respectively) was detected in the West Siberian region.
The developing resistance of plant pathogenic fungi to commercial fungicides has become a serious problem for efficient plant disease control. The use of antifungal preparations based on living ...microorganisms or their metabolites represents one of the possible environmentally friendly approaches. However, since a complete rejection of chemical fungicides is impossible, the combining of biopreparations and fungicides may be considered a promising biocontrol approach. Promising strains for the development of antifungal biopreparations include Penicillium fungi producing various biologically active compounds with antimicrobial and antiviral activities. A dry biomass of the P. chrysogenum F-24-28 strain (DMP) obtained from the P. chrysogenum VKPM F-1310 strain by induced mutagenesis possessed a high antifungal efficiency. According to in vitro experiments, supplementation of agarized medium with DMP (7.5–10 g/L) resulted in a significant growth inhibition in several plant pathogenic Fusarium fungi. The combination of DMP with a commercial azoxystrobin-based fungicide resulted in a prolonged growth inhibition in F. oxysporum, F. graminearum and F. culmorum even at fungicide concentrations significantly below the recommended level (0.5–2.5 mg/L or 2.5–12.5 g/ha vs. the recommended 100–275 g/ha). These results demonstrate a possibility to develop an efficient environmentally friendly biopreparation suitable to control crop diseases caused by a wide range of plant pathogens, and to prevent a possible selection and spreading of resistant pathogen strains.
PDF
