Population genetic analysis and trichothecene profiling of Fusarium graminearum from wheat in Uruguay

Fusarium graminearum sensu stricto (F. graminearum s.s.) is the major causal agent of Fusarium head blight of wheat worldwide, and contaminates grains with trichothecene mycotoxins that cause serious threats to food safety and animal health. An important aspect of managing this pathogen and reducing mycotoxin contamination of wheat is knowledge regarding its population genetics. Therefore, isolates of F. graminearum s.s. from the major wheat-growing region of Uruguay were analyzed by amplified fragment length polymorphism assays, PCR genotyping, and chemical analysis of trichothecene production. Of the 102 isolates identified as having the 15-ADON genotype via PCR genotyping, all were DON producers, but only 41 strains were also 15-ADON producers, as determined by chemical analysis. The populations were genotypically diverse but genetically similar, with significant genetic exchange occurring between them. Analysis of molecular variance indicated that most of the genetic variability resulted from differences between isolates within populations. Multilocus linkage disequilibrium analysis suggested that the isolates had a panmictic population genetic structure and that there is significant recombination occurs in F. graminearum s.s. In conclusion, tour findings provide the first detailed description of the genetic structure and trichothecene production of populations of F. graminearum s.s. from Uruguay, and expands our understanding of the agroecology of F. graminearum and of the correlation between genotypes and trichothecene chemotypes.Fil: Pan, D.. Universidad de la República; UruguayFil: Mionetto, A.. Universidad de la República; UruguayFil: Calero, N.. Universidad de la República; UruguayFil: Reynoso, Maria Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Torres, Adriana Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Bettucci, L.. Universidad de la República; Urugua

Characterization and Identification of the Basidiomycetous Fungus Associated with 'hoya de malvón' Grapevine Disease in Argentina

Inocutis jamaicensis (Murrill) Gottlieb, J.E. Wright & Moncalvo was identified as the basidiomycetous species associated with ‘hoja de malvón’ grapevine disease in Argentina. Macro and micro-morphological characteristics of fruit bodies corresponded to those described for the white-rotting fungus associated with native plant species and Eucalyptus globulus Labill. planted in Uruguay. Monokariotic isolates were obtained from basidiospores produced by fruit bodies of I. jamaicensis collected from Vitis vinifera L. and E. globulus. Dikaryons and fruit bodies produced by pairing monokaryotic mycelium suggest that all these isolates belong to the same species. The analysis of RFLP of the dikaryon produced by pairing monokaryons derived from V. vinifera and E. globulus revealed fragments that corresponded to each monokaryon, confirming that isolates from Vitis mated with those from Eucalyptus. In order to compare grapevine and Uruguayan isolates, RFLPs from ITS region generated by restriction digestion with Alu I, Hae III, Hha I, Msp I and Taq I were performed. Differences found in some restriction pattern could reflect a certain degree of variability between dikariotic isolates, probably related with a particular lifestyle, host specificity or geographic origin

Beta-blocker migraine prophylaxis affects the excitability of the visual cortex as revealed by transcranial magnetic stimulation

The objective of this study is to assess effects of beta-blocker migraine prophylaxis on cortical excitability determined by transcranial magnetic stimulation (TMS). Phosphene and motor thresholds (PT, MT) were investigated in 29 patients with migraine, in 15 of them prior to and following preventive medication with metoprolol and in 14 patients without prophylaxis. Following prophylaxis headache frequency significantly decreased (p = 0.005) and mean PT were significantly increased (51.5 ± 7.5 vs. 63.6 ± 8.4%) compared to patients without preventive treatment (53.7 ± 5.3 vs. 52.3 ± 6.3%; p = 0.040). Mean MT did not significantly differ either between groups or due to treatment. In the group of all patients, a significant inverse correlation between headache frequency and the level of PT was found (R = −0.629; p < 0.01). There was, however, no significant correlation in the subgroups of patients. We conclude that (a) clinical efficacy of beta-blocker treatment in migraine could be (at least partly) linked to its ability to modulate the excitability of the visual cortex and (b) the PT determined by TMS appears suitable to assess the effects of prophylaxis on cortical excitability in the individual patient. This may be useful in clinical trials investigating migraine preventive drugs