203 research outputs found

    DNA polymorphism among barley NILs of cv. Pallas, carrying genes for resistance to powdery mildew (Blumeria graminis f. sp. hordei)

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    Abstract. Barley powdery mildew, caused by the pathogen Blumeria graminis f. sp. hordei is an important disease of barley (Hordeum vulgare L.). The random amplified polymorphic DNA (RAPD) method was used to detect DNA polymorphism among 7 Pallas near-isogenic lines (NILs) carrying Mla3, Mla12, Mlk, Mlp, Mlat, Mlg and MlLa genes for resistance to B. graminis f. sp. hordei. From among 500 random 10-mer primers tested, 3 were specific for NIL P2 (Mla3), 1 for P10 (Mla12), 6 for P17 (Mlk), 46 for P19 (Mlp), 4 for P20 (Mlat), 6 for P21 (Mlg), and 4 for P23 (MlLa). The results of this study demonstrated that the RAPD technique is a useful tool for detecting DNA polymorphism among Pallas NILs

    Backloading – zmiana zasad aukcji uprawnień do emisji

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    The energy and climate package which was approved in 2009 defined ambitious target for reducing greenhouse gas emissions at least by 2020. The basis of the reformed EU ETS has become the auction of emissions allowances which is based on market mechanism. The financial crisis led to a significant reduction in greenhouse gas emissions and lower prices of the emission allowances. In order to raise of the EUAs price and improve the profitability of investment in renewable energy sources Commission aims to the adoption of the legislation that modifies the energy and climate package. The proposed administrative solutions consisting of change auctioning schedule seem to violate the treaty law and the principles on which was based EU ETS. This article presents the arguments against the adoption of the draft this legislation.Przyjęty w roku 2009 pakiet energetyczno-klimatyczny określił ambitne cele w zakresie redukcji emisji co najmniej do roku 2020. Podstawą zreformowanego EU ETS stała się aukcja uprawnień do emisji będąca wyrazem rynkowego charakteru tego systemu. Kryzys finansowy przyczynił się do znacznego ograniczenia emisji gazów cieplarnianych oraz spadku cen uprawnień do emisji. W celu podniesienia ich ceny oraz poprawienia opłacalności inwestycji w odnawialne źródła energii Komisja dąży do przyjęcia środków modyfikujących regulacje pakietu energetyczno-klimatycznego. Proponowane rozwiązania administracyjne polegające na zmianie harmonogramu aukcji uprawnień wydają się naruszać jednak prawo traktatowe oraz zasady na których oparty został system handlu uprawnieniami do emisji. Artykuł przedstawia argumenty przemawiające przeciwko przyjęciu projektu tej regulacji

    Novel induced mlo mutant alleles in combination with site-directed mutagenesis reveal functionally important domains in the heptahelical barley Mlo protein

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    <p>Abstract</p> <p>Background</p> <p>Recessively inherited natural and induced mutations in the barley <it>Mlo </it>gene confer durable broad-spectrum resistance against the powdery mildew pathogen, <it>Blumeria graminis </it>f.sp. <it>hordei</it>. <it>Mlo </it>codes for a member of a plant-specific family of polytopic integral membrane proteins with unknown biochemical activity. Resistant barley <it>mlo </it>mutant alleles identify amino acid residues that are critical for Mlo function in the context of powdery mildew susceptibility.</p> <p>Results</p> <p>We molecularly analyzed a novel set of induced barley <it>mlo </it>mutants and used site-directed mutagenesis in combination with transient gene expression to unravel novel amino acid residues of functional significance. We integrate these results with previous findings to map functionally important regions of the heptahelical Mlo protein. Our data reveal the second and third cytoplasmic loop as being particularly sensitive to functional impediment by mutational perturbation, suggesting that these regions are critical for the susceptibility-conferring activity of the Mlo protein. In contrast, only mutations in the second but not the third cytoplasmic loop appear to trigger the Endoplasmic Reticulum-localized quality control machinery that ensures the biogenesis of properly folded membrane proteins.</p> <p>Conclusion</p> <p>Our findings identify functionally important regions of the polytopic barley Mlo protein and reveal the differential sensitivity of individual protein domains to cellular quality control.</p

    Differences in Ear Rot Resistance and Fusarium verticillioides-Produced Fumonisin Contamination Between Polish Currently and Historically Used Maize Inbred Lines

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    Poland is the fifth largest European country, in terms of maize production. Ear rots caused by Fusarium spp. are significant diseases affecting yield and causing grain mycotoxin contamination. Inbred lines, which are commonly used in Polish breeding programs, belong, mostly, to two distinct genetic categories: flint and dent. However, historically used lines belonging to the heterotic Lancaster, IDT and SSS groups were also present in previous Polish breeding programs. In the current study, 98 inbred lines were evaluated across a 2-year-long experiment, after inoculation with F. verticillioides and under natural infection conditions. Lancaster, IDT, SSS and SSS/IDT groups were characterized as the most susceptible ones and flint as the more resistant. Based on the results obtained, the moderately resistant and most susceptible genotypes were defined to determine the content of fumonisins (FBs) in kernel and cob fractions using the HPLC method. Fumonisin's content was higher in the grain samples collected from inoculated plants than in cobs. The association of visible Fusarium symptoms with fumonisin concentration in grain samples was significant. Conversely, the cobs contained more FB1 under natural infection, which may be related to a pathogen's type of growth, infection time or presence of competitive species. Using ddRADseq genome sampling method it was possible to distinguish a basal relationship between moderately resistant and susceptible genotypes. Genetic distance between maize genotypes was high. Moderately resistant inbreed lines, which belong to IDT and IDT/SSS belong to one haplotype. Genotypes which belong to the flint, dent or Lancaster group, and were characterized as moderately resistant were classified separately as the same susceptible one. This research has demonstrated that currently grown Polish inbred lines, as well the ones used in the past are a valid source of resistance to Fusarium ear rot. A strong association was observed between visible Fusarium symptoms with fumonisin concentration in grain samples, suggesting that selection in maize for reduced visible molds should reduce the risk of mycotoxin contamination. NGS techniques provide new tools for overcoming the long selection process and increase the breeding efficiency

    Resistance to Powdery Mildew in Barley Recombinant Lines Derived from Crosses between Hordeum vulgare and Hordeum bulbosum

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    Barley recombinant lines obtained from crosses and backcrosses of common barley (Hordeum vulgare L.) cultivars Emir and Golden Promise with bulbosus barley grass (H. bulbosum L.) were tested against differential set of 14 Blumeria graminis D.C. Golovin ex Speer f. sp. hordei – synamorph Erysiphe graminis DC. f. sp. hordei Em Marchall isolates, pathogenic fungus causing powdery mildew. Powdery mildew resistance was found in 22 from 24 lines tested. Presence of unknown genes was postulated in 13 lines. In six of these lines the unknown genes were postulated present besides Mla12 allele originated from H. vulgare parent (cv. Emir). The only line resistant to infection, from all isolates used, was 181P94/1/3/1/1/1-2. Four other lines could be considered highly resistant, because they were susceptible to only one powdery mildew isolate. The possibilities to use the hybrid lines with identified resistance to powdery mildew, especially line 181P94/1/3/1/1/1-2 in barley breeding programs were discussed

    Pathotype variation of barley powdery mildew in Western Australia

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    Barley powdery mildew caused by the fungus Blumeria graminis f. sp. hordei (Bgh) has emerged as the most damaging disease of barley in Western Australia (WA). Many of the available cultivars display high levels of disease in the field when climatic conditions are conducive. As a result, fungicides have become the main method of disease control in the last 10 years. Different types and sources of genetic disease resistance are available but to optimise their deployment it is necessary to evaluate the spectrum of pathotypes present in the pathogen population. Sixty isolates of Bgh were collected in the 2009 season from 9 locations, single spored and characterised by infection on reference barley lines and cultivars. Eighteen unique pathotypes were resolved. Virulence against many of the R-genes in the reference lines was present in at least one pathotype. Isolates were virulent against 16 out of a total of 23 resistance gene combinations. Undefeated resistance genes included the major R-genes Mla-6, Mla-9, Ml-ra and the combinations of Mla-1 plus Mla-A12 and Mla-6 plus Mla-14 and Mla-13 plus Ml-Ru3 together with the recessive resistance gene mlo-5. There was significant pathotype spatial differentiation suggesting limited gene flow between different regions with WA or localised selection pressures and proliferation. On the basis of the results we recommend a number of strategies to manage powdery mildew disease levels within WA

    Resistance of (Aegilops tauschii × Secale cereale) × Triticosecale Hybrids to Leaf Rust (Puccinia triticina) Determined on the Macroscopic and Microscopic Level

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    Leaf rust caused by Puccinia triticina Eriks belongs to the most important fungal pathogens of wheat (Triticum aestivum L.) and triticale (× Triticosecale). Effective resistance to leaf rust is both, cost-effective and environmentally safe. Many wild Aegilops species carry unknown resistances against fungal diseases and are characterized by a high genetic variability. The main goal of this work was to examine the resistance of (Aegilops tauschii × Secale cereale) × Triticosecale hybrids to leaf rust in inoculation tests with different races of P. triticina. Hybrid plants were selected for the presence of 2D chromosome/s in the triticale background using fluorescence and genomic in situ hybridization. The presence of leaf rust resistance genes was confirmed with closely linked molecular markers, i.e., Xgdm35 and Xgwm296. 14 genotypes of BC2F4 – BC2F6 hybrid plants with the monosomic addition of chromosome 2D (M2DA) were analyzed together with nine control lines. Resistance was determined at the macroscopic and microscopic level at the seedling and adult plant stage (flag leaf). In general, results revealed limited resistance of hybrid plants at the seedling stage, followed by an increase of the resistance level at later stages of plant development. This indicates that respective hybrid plants may exhibit APR resistance conferred by Lr22a introgressed from Ae. tauschii. On the basis of the macroscopic and microscopic analysis, this kind of resistance turned out to be additive and race-specific. We selected four monosomic 2D addition triticale genotypes highly resistant to P. triticina infection at the two main stages of plant development. From the selected genotypes, we obtained 26 doubled haploid lines among which two lines with doubled additional chromosomes 2D of Ae. tauschii can be used for further breeding to increase leaf rust resistance of cultivated triticale

    Global genomic analyses of wheat powdery mildew reveal association of pathogen spread with historical human migration and trade

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    The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization.Centro de Investigaciones AgropecuariasFil: Sotiropoulos, Alexandros G. University of Zurich. Department of Plant and Microbial Biology; SuizaFil: Arango-Isaza, Epifanía. University of Zurich. Department of Evolutionary Biology and Environmental Studies; SuizaFil: Ban, Tomohiro. Yokohama City University. Kihara Institute for Biological Research; JapónFil: Barbieri, Chiara. University of Zurich. Department of Evolutionary Biology and Environmental Studies; SuizaFil: Barbieri, Chiara. Max Planck Institute for Evolutionary Anthropology. Department of Linguistic and Cultural Evolution; AlemaniaFil: Bourras, Salim. University of Zurich. Department of Plant and Microbial Biology; SuizaFil: Bourras, Salim. University of Agricultural Sciences. Department of Forest Mycology and Plant Pathology; SueciaFil: Cowger, Christina. North Carolina State University; Estados Unidos. USDA-ARS Department of Plant Pathology; Estados UnidosFil: Czembor, Paweł C. National Research Institute. Plant Breeding and Acclimatization Institute; PoloniaFil: Ben-David, Roi. ARO-Volcani Center. Institute of Plant Sciences. Department of Vegetables and Field Crops; IsraelFil: Dinoor, Amos. University of Jerusalem. The Robert H. Smith Faculty of Agriculture, Food & Environment. Department of Plant Pathology and Microbiology; IsraelFil: Ellwood, Simon R. Curtin University. School of Molecular and Life Sciences. Centre for Crop and Disease Management; AustraliaFil: Graf, Johannes. University of Zurich. Department of Plant and Microbial Biology; SuizaFil: Hatta, Koichi. National Agricultural Research Organization. Hokkaido Agricultural Research Center Field Crop Research and Development; JapónFil: Helguera, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias; ArgentinaFil: Wicker, Thomas. University of Zurich. Department of Plant and Microbial Biology; Suiz

    Wheat Stem Rust Back in Europe: Diversity, Prevalence and Impact on Host Resistance

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    The objective of this study was to investigate the re-emergence of a previously important crop pathogen in Europe, Puccinia graminis f.sp. tritici, causing wheat stem rust. The pathogen has been insignificant in Europe for more than 60 years, but since 2016 it has caused epidemics on both durum wheat and bread wheat in local areas in southern Europe, and additional outbreaks in Central- and West Europe. The prevalence of three distinct genotypes/races in many areas, Clade III-B (TTRTF), Clade IV-B (TKTTF) and Clade IV-F (TKKTF), suggested clonal reproduction and evolution by mutation within these. None of these genetic groups and races, which likely originated from exotic incursions, were detected in Europe prior to 2016. A fourth genetic group, Clade VIII, detected in Germany (2013), was observed in several years in Central- and East Europe. Tests of representative European wheat varieties with prevalent races revealed high level of susceptibility. In contrast, high diversity with respect to virulence and Simple Sequence Repeat (SSR) markers were detected in local populations on cereals and grasses in proximity to Berberis species in Spain and Sweden, indicating that the alternate host may return as functional component of the epidemiology of wheat stem rust in Europe. A geographically distant population from Omsk and Novosibirsk in western Siberia (Russia) also revealed high genetic diversity, but clearly different from current European populations. The presence of Sr31-virulence in multiple and highly diverse races in local populations in Spain and Siberia stress that virulence may emerge independently when large geographical areas and time spans are considered and that Sr31-virulence is not unique to Ug99. All isolates of the Spanish populations, collected from wheat, rye and grass species, were succesfully recovered on wheat, which underline the plasticity of host barriers within P. graminis. The study demonstrated successful alignment of two genotyping approaches and race phenotyping methodologies employed by different laboratories, which also allowed us to line up with previous European and international studies of wheat stem rust. Our results suggest new initiatives within disease surveillance, epidemiological research and resistance breeding to meet current and future challenges by wheat stem rust in Europe and beyond.info:eu-repo/semantics/publishedVersio
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