TY - JOUR A1 - Müller, M.E.H. A1 - Steier, I. A1 - Köppen, Robert A1 - Proske, Matthias A1 - Korn, U. A1 - Koch, Matthias A1 - Siegel, David T1 - Cocultivation of phytopathogenic Fusarium and Alternaria strains affects fungal growth and mycotoxin production N2 - Aims: A laboratory study was conducted to evaluate the influence of cocultivation of toxigenic Fusarium (F.) and Alternaria (A.) fungi with respect to growth and mycotoxin production. Methods and Results: Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were simultaneously or consecutively co-incubated on wheat kernels in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (DON, NIV and ZON) and three Alternaria toxins (AOH, AME and ALT) were analysed by a newly developed HPLC/MS/MS method. In simultaneous cocultures, the fungal biomass was enhanced up to 460% compared with individual cultures; Alternaria toxins were considerably depressed down to <5%. Combining At18 and At220 with Fg23 inhibited the toxin production of both fungal partners. In contrast, Fc13 increased its DON and ZON production in competitive interaction with both A. strains. Conclusions: The interfungal competitive effects aid the understanding of the processes of competition of both fungi in natural environments and the involvement of mycotoxins as antifungal factors. Significance and Impact of Study: Cocultivation significantly affects fungal growth and mycotoxin production of phytopathogenic Alternaria and Fusarium strains. The impact of mycotoxins on the interfungal competition is highlighted. KW - Alternaria KW - Cocultivation KW - Ergosterol KW - Fusarium KW - Interfungal competition KW - Multimycotoxin analysis PY - 2012 U6 - https://doi.org/10.1111/j.1365-2672.2012.05388.x SN - 1364-5072 VL - 113 IS - 4 SP - 874 EP - 887 PB - Wiley-Blackwell CY - Malden, Mass., USA AN - OPUS4-26932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schiro, G. A1 - Müller, T. A1 - Verch, G. A1 - Sommerfeld, Thomas A1 - Mauch, Tatjana A1 - Koch, Matthias A1 - Grimm, V. A1 - Müller, M.E.H. T1 - The distribution of mycotoxins in a heterogeneous wheat field in relation to microclimate, fungal and bacterial abundance N2 - Aim: To observe the variation in accumulation of Fusarium and Alternaria mycotoxins across a topographically heterogeneous field and tested biotic (fungal and bacterial abundance) and abiotic (microclimate) parameters as explanatory variables. Methods and Results: We selected a wheat field characterized by a diversified topography, to be responsible for variations in productivity and in canopy-driven microclimate. Fusarium and Alternaria mycotoxins where quantified in wheat ears at three sampling dates between flowering and harvest at 40 points. Tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), deoxynivalenol (DON), zearalenone (ZEN) and deoxynivalenol-3-Glucoside (DON.3G) were quantified. In canopy temperature, air and soil humidity were recorded for each point with data-loggers. Fusarium spp. as trichothecene producers, Alternaria spp. and fungal abundances were assessed using qPCR. Pseudomonas fluorescens bacteria were quantified with a culture based method. We only found DON, DON.3G, TeA and TEN to be ubiquitous across the whole field, while AME, AOH and ZEN were only occasionally detected. Fusarium was more abundant in spots with high soil humidity, while Alternaria in warmer and drier spots. Mycotoxins correlated differently to the observed explanatory variables: positive correlations between DON accumulation, tri 5 gene and Fusarium abundance were clearly detected. The correlations among the others observed variables, such as microclimatic conditions, varied among the sampling dates. The results of statistical model identification do not exclude that species coexistence could influence mycotoxin production. Conclusions: Fusarium and Alternaria mycotoxins accumulation varies heavily across the field and the sampling dates, providing the realism of landscapescale studies. Mycotoxin concentrations appear to be partially explained by biotic and abiotic variables. Significance and Impact of the Study: We provide a useful experimental design and useful data for understanding the dynamics of mycotoxin biosynthesis in wheat. KW - Alternaria KW - Deoxynivalenol KW - Food Safety KW - Fusarium KW - Pseudomonas fluorescens KW - Tenuazonic acid PY - 2019 U6 - https://doi.org/10.1111/jam.14104 SN - 1365-2672 SN - 1364-5072 VL - 126 IS - 1 SP - 177 EP - 190 PB - Wiley AN - OPUS4-47161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -