176 research outputs found

    Polymorphism of mycotoxin biosynthetic genes among Fusarium equiseti isolates from Italy and Poland

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    Fusarium equiseti (Corda) Saccardo is a soil saprophyte and a weak pathogen, associated with several diseases of fruit and other crops in subtropical and tropical areas, but also in countries with temperate climate. A wide range of secondary metabolites has been identified among natural F. equiseti populations, with zearalenone (ZEA), fusarochromanone and fusarenon-X being the most common. In present study, the genetic diversity of strains from two populations (from Italy and Poland) was evaluated by analysing the translation elongation factor 1α (tef-1α) sequences, two polyketide synthases from the ZEA biosynthetic pathway (PKS13 and PKS4) and the TRI5 gene from the trichothecene biosynthetic pathway. ZEA was produced in rice cultures by 20 of the 27 tested isolates in concentrations ranging from 1.34 ng/g to 34,000 ng/g). The ability to produce enniatins and trichothecenes was evaluated in all strains by identifying esyn1, TRI13 and TRI4 genes. The presence of PKS4 and PKS13 genes was confirmed by polymerase chain reaction (PCR) in only some ZEA-producing isolates. Similarly, the TRI5 gene was found in 14 of the 27 isolates tested. This is likely to have been caused by the divergence of those genes between F. equiseti and F. graminearum (the latter species was used for the primers design) and can be exploited in phylogenetic studies. The analysis of the mycotoxin biosynthetic gene sequences can be used to differentiate the studied genotypes even more precisely than the analysis of the non-coding regions (like tef-1α)

    Fumonisins and related Fusarium species in pre-harvest maize ear rot in Poland

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    Two Fusarium species were identified in mouldy maize ears with the highest frequency during 2005–2014 in 7 seasons: F. subglutinans (3.1–42.0%) and F. verticillioides (44.1–70.3%). Two other species were also found but with lower frequency: F. graminearum (1.0–13.0%) and F. poae (1–45.7%). In 2005 fumonisin FB1, and in 2013 and 2014 three fumonisins (FBs) – FB1, FB2 and FB3 — were identified in harvest samples. The Fusarium-damaged kernel (FDK) fraction contained almost the totality of mycotoxins (90.0–95.0%), while healthy looking kernels (HLK) contained only below 5.0 to 10.0%. Kernels naturally infected by F. verticillioides and F. proliferatum contained (in mg kg−1) up to 710.00 of fumonisin B1, up to 209.72 of fumonisin B2 and up to 35.72 of fumonisin B3

    Preliminary studies of fungi in the Biebrza National Park (NE Poland). Part III. Micromycetes – new data

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    Ecological information concerning 292 fungal taxa is reported as a result of two surverys in the Biebrza National Park. Most data presented come from the 5-day all-fungi inventory of the Polish Mycological Society in 2013, and 47 species were recorded during studies in the Biele Suchowolskie fen in 2008/2009. In total, 27 species of zygomycetes, 232 ascomycetes (including anamorphs) and 27 basidiomycetes (mainly Pucciniales). Additionaly some representatives of fungi-like organisms from Stramenopiles (4 species) and Dictyostelia (2) were identified. Fungal groups included were the same as in the previous survey in 2012: 190 taxa associated with plants, 15 with animals, 8 with fungi and 71 isolated from soil, plant debris and animal excrements. The most numerous were anamorphic ascomycetes (159 species). Nineteen species have not been previously known from Poland and 31 species are rare (1–3 localities). For the Biebrza National Park 197 species (67.5%) are new

    Aegilops-Secale amphiploids: chromosome categorisation, pollen viability and identification of fungal disease resistance genes

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    The aim of this study was to assess the potential breeding value of goatgrass-rye amphiploids, which we are using as a “bridge” in a transfer of Aegilops chromatin (containing, e.g. leaf rust resistance genes) into triticale. We analysed the chromosomal constitution (by genomic in situ hybridisation, GISH), fertility (by pollen viability tests) and the presence of leaf rust and eyespot resistance genes (by molecular and endopeptidase assays) in a collection of 6× and 4× amphiploids originating from crosses between five Aegilops species and Secale cereale. In the five hexaploid amphiploids Aegilops kotschyi × Secale cereale (genome UUSSRR), Ae. variabilis × S. cereale (UUSSRR), Ae. biuncialis × S. cereale (UUMMRR; two lines) and Ae. ovata × S. cereale (UUMMRR), 28 Aegilops chromosomes were recognised, while in the Ae. tauschii × S. cereale amphiploid (4×; DDRR), only 14 such chromosomes were identified. In the materials, the number of rye chromosomes varied from 14 to 16. In one line of Ae. ovata × S. cereale, the U-R translocation was found. Pollen viability varied from 24.4 to 75.4%. The leaf rust resistance genes Lr22, Lr39 and Lr41 were identified in Ae. tauschii and the 4× amphiploid Ae. tauschii × S. cereale. For the first time, the leaf rust resistance gene Lr37 was found in Ae. kotschyi, Ae. ovata, Ae. biuncialis and amphiploids derived from those parental species. No eyespot resistance gene Pch1 was found in the amphiploids

    Metabolic profiles in five high-producing Swedish dairy herds with a history of abomasal displacement and ketosis

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    <p>Abstract</p> <p>Background</p> <p>Body condition score and blood profiles have been used to monitor management and herd health in dairy cows. The aim of this study was to examine BCS and extended metabolic profiles, reflecting both energy metabolism and liver status around calving in high-producing herds with a high incidence of abomasal displacement and ketosis and to evaluate if such profiles can be used at herd level to pinpoint specific herd problems.</p> <p>Methods</p> <p>Body condition score and metabolic profiles around calving in five high-producing herds with high incidences of abomasal displacement and ketosis were assessed using linear mixed models (94 cows, 326 examinations). Cows were examined and blood sampled every three weeks from four weeks ante partum (ap) to nine weeks postpartum (pp). Blood parameters studied were glucose, fructosamine, non-esterified fatty acids (NEFA), insulin, β-hydroxybutyrate, aspartate aminotransferase, glutamate dehydrogenase, haptoglobin and cholesterol.</p> <p>Results</p> <p>All herds had overconditioned dry cows that lost body condition substantially the first 4–6 weeks pp. Two herds had elevated levels of NEFA ap and three herds had elevated levels pp. One herd had low levels of insulin ap and low levels of cholesterol pp. Haptoglobin was detected pp in all herds and its usefulness is discussed.</p> <p>Conclusion</p> <p>NEFA was the parameter that most closely reflected the body condition losses while these losses were not seen in glucose and fructosamine levels. Insulin and cholesterol were potentially useful in herd profiles but need further investigation. Increased glutamate dehydrogenase suggested liver cell damage in all herds.</p

    Species diversity of Trichoderma in Poland

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    In the present study, we reinvestigate the diversity of Trichoderma in Poland utilizing a combination of morphological and molecular/phylogenetic methods. A total of 170 isolates were collected from six different substrata at 49 sites in Poland. These were divided among 14 taxa as follows: 110 of 170 Trichoderma isolates were identified to the species level by the analysis of their ITS1, ITS2 rDNA sequences as: T. harzianum (43 isolates), T. aggressivum (35), T. citrinoviride (11), T. hamatum (9), T. virens (6), T. longibrachiatum (4), T. polysporum (1), and T. tomentosum (1); 60 isolates belonging to the Viride clade were identified based on a fragment of the translation-elongation factor 1-alpha (tef1) gene as: T. atroviride (20 isolates), T. gamsii (2), T. koningii (17), T. viridescens (13), T. viride (7), and T. koningiopsis (1). Identifications were made using the BLAST interface in TrichOKEY and TrichoBLAST (http://www.isth.info). The most diverse substrata were soil (nine species per 22 isolates) and decaying wood (nine species per 75 isolates). The most abundant species (25%) isolated from all substrata was T. harzianum

    Impact of food processing and detoxification treatments on mycotoxin contamination

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