945 resultados para Rust fungi


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A series of flooding events occurred in Queensland, Australia during December 2010 and January 2011. The state’s capital city of Brisbane experienced major flooding in January 2011, when the Brisbane River broke its bank and inundated low lying areas.

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Many fungi, lichens, and bacteria produce xanthones (derivatives of 9H-xanthen-9-one, “xanthone” from the Greek “xanthos”, for “yellow”) as secondary metabolites. Xanthones are typically polysubstituted and occur as either fully aromatized, dihydro-, tetrahydro-, or, more rarely, hexahydro-derivatives. This family of compounds appeals to medicinal chemists because of their pronounced biological activity within a notably broad spectrum of disease states, a result of their interaction with a correspondingly diverse range of target biomolecules. This has led to the description of xanthones as “privileged structures”.(1) Historically, the total synthesis of the natural products has mostly been limited to fully aromatized targets. Syntheses of the more challenging partially saturated xanthones have less frequently been reported, although the development in recent times of novel and reliable methods for the construction of the (polysubstituted) unsaturated xanthone core holds promise for future endeavors. In particular, the fascinating structural and biological properties of xanthone dimers and heterodimers may excite the synthetic or natural product chemist.

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Filamentous fungi are important organisms for basic discovery, industry, and human health. Their natural growth environments are extremely variable, a fact reflected by the numerous methods developed for their isolation and cultivation. Fungal culture in the laboratory is usually carried out on agar plates, shake flasks, and bench top fermenters starting with an inoculum that typically features fungal spores. Here we discuss the most popular methods for the isolation and cultivation of filamentous fungi for various purposes with the emphasis on enzyme production and molecular microbiology.

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As a large, isolated and relatively ancient landmass, New Zealand occupies a unique place in the biological world, with distinctive terrestrial biota and a high proportion of primitive endemic forms. Biology Aotearoa covers the origins, evolution and conservation of the New Zealand flora, fauna and fungi. Each chapter is written by specialists in the field, often working from different perspectives to build up a comprehensive picture. Topics include: the geological history of our land origins, and evolution of our plants, animals and fungi current status of rare and threatened species past, present and future management of native species the effect of human immigration on the native biota. Colour diagrams and photographs are used throughout the text. This book is suitable for all students of biology or ecology who wish to know about the unique nature of Aotearoa New Zealand and its context in the biological world.

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Elevated levels of fungi in indoor environments have been linked with mould/moisture damage in building structures. However, there is a lack of information about “normal” concentrations and flora as well as guidelines of viable fungi in the school environment in different climatic conditions. We have reviewed existing guidelines for indoor fungi and the current knowledge of the concentrations and flora of viable fungi in different climatic areas, the impact of the local factors on concentrations and flora of viable fungi in school environments. Meta-regression was performed to estimate the average behaviour for each analysis of interest, showing wide variation in the mean concentrations in outdoor and indoor school environments (range: 101-103 cfu/m3). These concentrations were significantly higher for both outdoors and indoors in the moderate than in the continental climatic area, showing that the climatic condition was a determinant for the concentrations of airborne viable fungi. The most common fungal species both in the moderate and continental area were Cladosporium spp. and Penicillium spp. The suggested few quantitative guidelines for indoor air viable fungi for school buildings are much lower than for residential areas. This review provides a synthesis, which can be used to guide the interpretation of the fungi measurements results and help to find indications of mould/moisture in school building structures.

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There is currently a lack of reference values for indoor air fungal concentrations to allow for the interpretation of measurement results in subtropical school settings. Analysis of the results of this work established that, in the majority of properly maintained subtropical school buildings, without any major affecting events such as floods or visible mould or moisture contamination, indoor culturable fungi levels were driven by outdoor concentration. The results also allowed us to benchmark the “baseline range” concentrations for total culturable fungi, Penicillium spp., Cladosporium spp. and Aspergillus spp. in such school settings. The measured concentration of total culturable fungi and three individual fungal genera were estimated using Bayesian hierarchical modelling. Pooling of these estimates provided a predictive distribution for concentrations at an unobserved school. The results indicated that “baseline” indoor concentration levels for indoor total fungi, Penicillium spp., Cladosporium spp. and Aspergillus spp. in such school settings were generally ≤ 1450, ≤ 680, ≤ 480 and ≤ 90 cfu/m3, respectively, and elevated levels would indicate mould damage in building structures. The indoor/outdoor ratio for most classrooms had 95% credible intervals containing 1, indicating that fungi concentrations are generally the same indoors and outdoors at each school. Bayesian fixed effects regression modeling showed that increasing both temperature and humidity resulted in higher levels of fungi concentration.

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Nine new species of smut fungi, belonging to eight genera, are described from Australia: Dermatosorus schoenoplecti Vánky & R.G. Shivas, on Schoenoplectus mucronatus, Entyloma grampiansis Vánky & R.G. Shivas, on Hydrocotyle laxiflora, Macalpinomyces brachiariae Vánky, C. Vánky & R.G. Shivas, on Brachiaria holosericea, M. digitariae Vánky & R.G. Shivas, on Digitaria gibbosa, Restiosporium baloskionis Vánky & R.G. Shivas, on Baloskion tetraphyllum, Thecaphora maireanae R.G. Shivas & Vánky, on Maireana pentagona, Tilletia cape yorkensis Vánky & R.G. Shivas, on Whiteochloa airoides, Urocystis chorizandrae J. Cunnington, R.G. Shivas & Vánky, on Chorizandra enodis, and Ustanciosporium tenellum R.G . Shivas & Vánky, on Cyperus tenellus. New combinations are: Macalpinomyces ordensis(R.G. Shivas & Vánky) Vánky & R.G. Shivas (based on Sporisorium ordense, type on Brachiaria pubigera, Australia), and Sporisorium setariae (McAlpine) Vánky & R.G. Shivas (based on Sorosporium setariae, type on Setaria glauca, Australia).

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There are about 250 species of smut fungi known from Australia of which 95 are endemic. Fourteen of these endemic species were first collected in the period culminating with the publication of Daniel McAlpine's revision of Australian smut fungi in 1910. Of the 68 species treated by McAlpine, 10 were considered to be endemic to Australia at that time. Only 23 of the species treated by McAlpine have names that are currently accepted . During the following eighty years until 1990, a further 31 endemic species were collected and just 11 of these were named and described in that period. Since 1990, 50 further species of endemic smut fungi have been collected and named in Australia . There are 115 species that are restricted to either Australia or to Australia and the neighbouring countries of Indonesia, New Zealand, Papua New Guinea and the Philippines . These 115 endemic species occur in 24 genera, namely Anthracoidea (1 species), Bauerago (1), Cintractia (3), Dermatosorus (1), Entyloma (3), Farysporium (1), Fulvisporium (1), Heterotolyposporium (1), Lundquistia (1), Macalpinomyces (4), Microbotryum (2), Moreaua (20), Pseudotracya (1), Restiosporium (5), Sporisorium (26), Thecaphora (2), Tilletia (12), Tolyposporella (1), Tranzscheliella (1), Urocystis (2), Ustanciosporium (1), Ustilago (22), Websdanea (1) and Yelsemia (2). About a half of these local and regional endemic species occur on grasses and a quarter on sedges . The northern tropical savannah region of Australia offers most promise for the discovery of new endemic species . The agricultural, quarantine and environmental significance to Australia of some introduced species is discussed.

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As part of a comparative mapping study between sugarcane and sorghum, a sugarcane cDNA clone with homology to the maize Rp1-D rust resistance gene was mapped in sorghum. The cDNA probe hybridised to multiple loci, including one on sorghum linkage group (LG) E in a region where a major rust resistance QTL had been previously mapped. Partial sorghum Rp1-D homologues were isolated from genomic DNA of rust-resistant and -susceptible progeny selected from a sorghum mapping population. Sequencing of the Rp1-D homologues revealed five discrete sequence classes: three from resistant progeny and two from susceptible progeny. PCR primers specific to each sequence class were used to amplify products from the progeny and confirmed that the five sequence classes mapped to the same locus on LG E. Cluster analysis of these sorghum sequences and available sugarcane, maize and sorghum Rp1-D homologue sequences showed that the maize Rp1-D sequence and the partial sugarcane Rp1-D homologue were clustered with one of the sorghum resistant progeny sequence classes, while previously published sorghum Rp1-D homologue sequences clustered with the susceptible progeny sequence classes. Full-length sequence information was obtained for one member of a resistant progeny sequence class ( Rp1-SO) and compared with the maize Rp1-D sequence and a previously identified sorghum Rp1 homologue ( Rph1-2). There was considerable similarity between the two sorghum sequences and less similarity between the sorghum and maize sequences. These results suggest a conservation of function and gene sequence homology at the Rp1 loci of maize and sorghum and provide a basis for convenient PCR-based screening tools for putative rust resistance alleles in sorghum.

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An annotated checklist of the smut fungi (Ustilaginomycetes) from Thailand has been compiled after an examination of the scientific literature, previously deposited herbarium specimens and specimens collected by the authors during a survey in December 2005. Fifty-two species of smut fungi are listed, including 11 species which were newly discovered during our survey. Most of these smut fungi are reported for the first time from Thailand. Several species are very rare, being known only from the type material or a limited number of collections.

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Six new smut fungi, Sporisorium rarum (type on Eulalia aurea), S. vermiculum (type on Sarga plumosa), S. xerofasciculatum (type on Xerochloa laniflora), Tilletia xerochloae (type on Xerochloa laniflora), T. yakirrae (type on Yakirra majuscula) and Ustilago lunata (type on Triodia longiceps), are described and illustrated from central and western Australia. Keys are provided for the smut fungi on Sarga and Xerochloa.

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In contrast to a published report [Wali et al. Arch Microbiol 118:49–53 (1978)], an organic acid is not essential for the growth of thermophilic fungi. The thermophilic fungus, Thermomyces lanuginosus, grows satisfactorily in a synthetic medium containing glucose as carbon source if the pH of the medium is controlled. The control of pH is essential for the concentration of carbon dioxide in the growth medium and the activity of anaplerotic enzyme, pyruvate carboxylase.

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Aims: To assay sago starch from Papua New Guinea (PNG) for important mycotoxins and to test fungal isolates from sago for mycotoxin production in culture. Methods and Results: Sago starch collected from Western and East Sepik Provinces was assayed for aflatoxins, ochratoxin A, cyclopiazonic acid, sterigmatocystin, citrinin and zearalenone and all 51 samples were negative. Frequently isolated species of Penicillium (13), Aspergillus (five) and Fusarium (one) were cultured on wheat grain, and tested for the production of ochratoxin A, cyclopiazonic acid, sterigmatocystin, citrinin, patulin and penicillic acid. All 12 isolates of P. citrinin and one of two A. flavipes isolates produced citrinin. A single isolate of A. versicolor produced sterigmatocystin. No other mycotoxins were detected in these cultures. Conclusions: No evidence was found of systemic mycotoxin contamination of sago starch. However, the isolation of several mycotoxigenic fungi shows the potential for citrinin and other mycotoxins to be produced in sago stored under special conditions. Significance and Impact of the study: Sago starch is the staple carbohydrate in lowland PNG and the absence of mycotoxins in freshly prepared sago starch is a positive finding. However, the frequent isolation of citrinin-producing fungi indicates a potential health risk for sago consumers, and food safety is dependant on promoting good storage practices.

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A new smut fungus, Ustilago lituana, is described and illustrated on the grass Triodia epactia from Western Australia. It is compared with the three known smut fungi on Triodia and a key for identifying these species is given.