32 research outputs found

    The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

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    © 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity

    Fluctuations and Ice-Flow Velocity of the Northeast and McClary Glacier on the Antarctic Peninsula Derived from Remote Sensing Data and SAR Interferometry

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    Entwicklung und Anwendung von Methoden für einen frühen Nachweis der Flugbranderreger Ustilago nuda und U. tritici in Gerste und Weizen

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    Infestation of barley (Hordeum vulgare) and wheat (Triticum aestivum) with loose smut (pathogen: Ustilago nuda and U. tritici, resp.) is not visible until the appearance of the smutted head. Both the development of seed treatment products for loose smut control and the breeding for loose smut resistance could be accelerated if it were possible to earlier detect and quantify an infestation with loose smut. In the present work the development of the fungus in its host plant was monitored by fluorescence microscopy with the aim to test and establish such methods. Mycelium which invaded the shoot apical meristem (SAM) and the leaf primordia could be observed in hand sections stained with the fluorophore Blankophor, within a few days after sowing. At the one node stage the ear primordia were already heavily affected and the fungus was regularly present in the nodes as well. Furthermore, with a polyclonal antibody-based DAS-ELISA it was possible to detect the fungus inside the host plant. U. nuda protein content in the area of the SAM could be reliably quantified in spring barley already at the three leaf stage (10-14 days after sowing), and future ear symptoms could be predicted. For winter wheat a sufficient prediction was not possible until the one node stage. After application of efficient seed treatments (chemical treatment with Sedaxane or Raxil [active ingredient: tebuconazole] and warm or hot water treatment, resp.) amounts of the U. nuda protein were generally below 500 ng/ml and thus in a similar range as in plants grown from healthy grains. Microscopic analyses performed in parallel suggested that the mycelium, depending on the method applied, died off rapidly (seed treatment with Sedaxane) or temporarily persisted in a damaged condition (seed treatment with tebuconazole, hot water treatment). After seed treatment with extracts of rhubarb (Rheum rhabarbarum) root or butterbur (Petasites officinales) at the three leaf and one node stage partially lower amounts of U. nuda resp. U. tritici protein were determined than in the controls, suggesting an activity of these agents. However, the treatment had no or only little effect on the incidence of smutted heads. Moreover, a protocol for specific amplification and quantification of U. nuda resp. U. tritici DNA (real-time PCR) was established. DNA was extracted from infected plants and amplified with fungus-specific primers. Also with this method a prediction of an infestation with loose smut was possible already at the three leaf stage. Overall, there were good matches concerning the results of microscopy, DAS-ELISA and real-time PCR. The latter, however, was more sensitive by a factor of 250 than the immunological approach. The results of this work showed that the development of early test systems for predicting loose smut infestation is possible with various methods, indeed. Though, for routine use optimizations are necessary, as in the case of DAS-ELISA, a safer assess of the U. nuda protein content (threshold), at which an ear infestation is to be expected or, when using all of the methods, the use of seed stocks that are germinating unabatedly well in spite of high infection rates

    Entwicklung und Anwendung von Methoden für einen frühen Nachweis der Flugbranderreger Ustilago nuda und U. tritici in Gerste und Weizen

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    Infestation of barley (Hordeum vulgare) and wheat (Triticum aestivum) with loose smut (pathogen: Ustilago nuda and U. tritici, resp.) is not visible until the appearance of the smutted head. Both the development of seed treatment products for loose smut control and the breeding for loose smut resistance could be accelerated if it were possible to earlier detect and quantify an infestation with loose smut. In the present work the development of the fungus in its host plant was monitored by fluorescence microscopy with the aim to test and establish such methods. Mycelium which invaded the shoot apical meristem (SAM) and the leaf primordia could be observed in hand sections stained with the fluorophore Blankophor, within a few days after sowing. At the one node stage the ear primordia were already heavily affected and the fungus was regularly present in the nodes as well. Furthermore, with a polyclonal antibody-based DAS-ELISA it was possible to detect the fungus inside the host plant. U. nuda protein content in the area of the SAM could be reliably quantified in spring barley already at the three leaf stage (10-14 days after sowing), and future ear symptoms could be predicted. For winter wheat a sufficient prediction was not possible until the one node stage. After application of efficient seed treatments (chemical treatment with Sedaxane or Raxil [active ingredient: tebuconazole] and warm or hot water treatment, resp.) amounts of the U. nuda protein were generally below 500 ng/ml and thus in a similar range as in plants grown from healthy grains. Microscopic analyses performed in parallel suggested that the mycelium, depending on the method applied, died off rapidly (seed treatment with Sedaxane) or temporarily persisted in a damaged condition (seed treatment with tebuconazole, hot water treatment). After seed treatment with extracts of rhubarb (Rheum rhabarbarum) root or butterbur (Petasites officinales) at the three leaf and one node stage partially lower amounts of U. nuda resp. U. tritici protein were determined than in the controls, suggesting an activity of these agents. However, the treatment had no or only little effect on the incidence of smutted heads. Moreover, a protocol for specific amplification and quantification of U. nuda resp. U. tritici DNA (real-time PCR) was established. DNA was extracted from infected plants and amplified with fungus-specific primers. Also with this method a prediction of an infestation with loose smut was possible already at the three leaf stage. Overall, there were good matches concerning the results of microscopy, DAS-ELISA and real-time PCR. The latter, however, was more sensitive by a factor of 250 than the immunological approach. The results of this work showed that the development of early test systems for predicting loose smut infestation is possible with various methods, indeed. Though, for routine use optimizations are necessary, as in the case of DAS-ELISA, a safer assess of the U. nuda protein content (threshold), at which an ear infestation is to be expected or, when using all of the methods, the use of seed stocks that are germinating unabatedly well in spite of high infection rates

    Assessment of the loose smut fungi (Ustilago nuda and U. tritici) in tissues of barley and wheat by fluorescence microscopy and real-time PCR

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    Loose smut fungi of barley and wheat (Ustilago nuda and U. tritici, respectively) colonize the plant without causing obvious disease symptoms before heading. The availability of diagnostic methods to detect and follow the growth of these pathogens in the plant would therefore be highly advantageous for both resistance breeding and the development of effective seed treatments. Using seed lots of barley and wheat highly infected with loose smut, we studied the early establishment of the loose smut pathogens in the plant by fluorescence microscopy. In hand-cut sections stained with the fluorochrome Blankophor®, fungal hyphae were observed to invade the shoot apical meristem and leaf primordia during the first days after the onset of germination. At the first node stage the ear and leaf primordia were generally extensively colonized. Hyphae of U. nuda were also regularly observed in high density in the nodes. A protocol was developed for the specific amplification of U. nuda and U. tritici DNA extracted from infected plant tissue. PCR screening of U nuda in seedlings from infected and healthy seed lots was compared to ELISA, microscopy and ultimately head infection of mature plants derived from tillers of the tested seedlings. The results indicated that a prediction of loose smut infection by real-time PCR is possible at the second leaf stage, and that the assay is equally suited for use with spring and winter varieties of barley and wheat
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