Helminthosporium Maydis
Mostrando 1-12 de 36 artigos, teses e dissertações.
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1. Ocorrência de Bipolaris maydis causando mancha foliar em Paspalum atratum cv. Pojuca no Brasil
Bipolaris maydis was consistently isolated from infected Paspalum atratum cv. Pojuca plants showing leaf spot symptoms in the Cerrado of Brazil, in 2002. Pathogenicity tests under greenhouse conditions and subsequent reisolations of B. maydis from artificially inoculated Pojuca seedlings confirmed the hypothesis that this fungus was the causal agent of the d
Fitopatologia Brasileira. Publicado em: 2004-12
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2. Variação genética entre patógenos agentes da doença de "Helminthosporium" de arroz, milho e trigo
Vinte amostras de espécies de fungos, agentes da helmintosporiose em cereais, foram obtidas de diferentes regiões geográficas, sendo nove constituídas de Bipolarisoryzae, isoladas de cultura do arroz (Oryza sativa), sete de B.sorokiniana coletadas de trigo (Triticum aestivum), duas de B.maydis e duas de Exserohilumturcicum provenientes de milho (Zea mays
Fitopatologia Brasileira. Publicado em: 2002-11
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3. Lack of Toxicity of Helminthosporium maydis-Invaded Corn and Culture Filtrates to Chicks and Mice 1
Six isolates of Helminthosporium maydis, obtained from southern leaf blight-damaged corn, were grown separately on autoclaved corn and fed to chicks and mice to evaluate their toxigenicity. Two-, three-, and four-week-old culture filtrates from three pathogenic isolates grown separately on modified Fries medium were also evaluated for toxigenicity. None of t
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4. Evaluation of a Chemical Method for Assay of Helminthosporium maydis Race T Toxin 1
A chemical test reported by Karr et al. (Plant Physiol. 55:727) to assay for host-specific toxin produced by Helminthosporium maydis race T was evaluated. Preparations from culture filtrates of both race T isolates, containing host-specific toxin, and similar preparations from race O isolates, containing no detectable host-specific toxin, gave positive react
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5. Electrophoretic Comparison of Mitochondrial Polypeptides from Maize Lines Susceptible and Resistant to Helminthosporium maydis Race T 1
The mitochondrial polypeptides from maize lines susceptible and resistant to Helminthosporium maydis were studied by single- and two-dimensional gel electrophoresis. Approximately 120 polypeptides were detected by two-dimensional gel electrophoresis. However, it was not possible to detect qualitative differences between the mitochondrial polypeptides of the
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6. Assay for Helminthosporium maydis Toxin-binding Activity in Plants 1
A relatively rapid and sensitive assay is described for assessing the binding of Helminthosporium maydis Race T14 C-toxins I and II to plant components. The technique is a modification of the one of Haddad and Birge (J. Biol. Chem. 250: 299-303, 1975), and utilizes dextran-coated charcoal as an adsorbent for the unreacted toxin and employs a Millipore filter
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7. Effect of Thiamine on Ethanol and Pyruvate Production in Helminthosporium maydis12
Growth of the fungus Helminthosporium maydis race T in a basal glucose-l-asparagine liquid medium, pH 5, is inhibited by thiamine-HCl. Analysis of the media for organic acids reveals that the extracellular pyruvate concentration decreases as the thiamine-HCl concentration of the medium increases. Extracellular ethanol, in contrast to pyruvate, increases in c
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8. Studies of the Toxicity of Helminthosporium maydis1
Isolates of Helminthosporium maydis from blighted corn were tested for toxicity in mice, rats, swine, rabbits, microorganisms, and tissue culture. Extracts of grains, mycelia, and culture supernatant fluids killed mice on intraperitoneal (ip) injection, but were nontoxic on administration by mouth to swine. The toxin was partially purified and appears to be
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9. Force Required to Detach Conidia of Helminthosporium maydis
The force required to break the conidium-conidiophore attachment in Helminthosporium maydis was measured by centrifugation and by a small jet of air. The force which removed half the spores from their stalks was found by both methods to be about 1 × 10−2 dynes. The corresponding speed of the air jet was about 10 m/sec. Although spores are removed over a r
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10. Influence of Helminthosporium maydis, Race T, Toxin on Potassium Uptake in Maize Roots 12
The effect of a toxin extract of Helminthosporium maydis, race T on K+ (86Rb) uptake by excised root segments of normal (N) and Texas cytoplasmic male-sterile (T) versions of corn inbred W64A was investigated. The uptake of K+ was inhibited in both N and T roots by the toxin. This was true for both basal (freshly excised) and augmented (pretreated with aerat
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11. Effects of Purified Helminthosporium maydis Race T Toxin on the Structure and Function of Corn Mitochondria and Protoplasts
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12. The Toxins of Helminthosporium maydis (Race T) 1: A Colorimetric Determination of the Toxins, Their Appearance in Culture and in Infected Plants
Host-specific toxins produced by Helminthosporium maydis, race T, are measured quantitatively by a chemical assay procedure involving reaction of the toxins with a sulfuric acidacetic anhydride reagent and measurement of the absorbance of the product at 330 nm. The assay was shown to measure total toxin concentrations after only limited fractionation of the