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Sample records for phytophthora nicotianae van

  1. Citroenzuur- en nicotinegehalte in enkele variëteiten van Nicotiana tabacum en Nicotiana rustica

    NARCIS (Netherlands)

    Fatton, Numa Edouard

    1939-01-01

    Van technisch rijpe bladen van verschillende varieteiten van Nicotiana rustica en Nicotiana Tabacum werden het citroenzuuren het nicotinegehalte bepaald, uitgedrukt in % op de droge stof. Hetzelfde werd gedaan van bladmoes en hoofdnerf afzonderlijk, verder van de wortel, de stengel, de bloemen en de

  2. E-beam irradiation for the control of Phytophthora nicotianae var. nicotianae in stonewool cubes

    Directory of Open Access Journals (Sweden)

    Ptaszek Magdalena

    2015-09-01

    Full Text Available Effectiveness of electron beam irradiation was evaluated against Phytophthora nicotianae var. nicotianae, the causal agent of stem base and root rot of tomato. In laboratory trials, irradiation of 7-day-old Phytophthora cultures growing on potato-dextrose-agar (PDA medium with 1 kGy resulted in the disintegration of the pathogen’s hyphae. Increasing the irradiation dose to 3 kGy caused decay of the hyphae. Irradiation of infested stonewool with 5 kGy caused decrease of the pathogen population about 5 times. Application of 20 kGy completely eliminated the pathogen from stonewool. Irradiation of substratum resulted in significant increase of tomato seedlings healthiness, especially when the dose 20 kGy was applied.

  3. De rol van heterotrimere G-eiwitten in de ontwikkeling en virulentie van Phytophthora infestans

    NARCIS (Netherlands)

    Latijnhouwers, M.

    2003-01-01

    Onderzoek naar de ziekteverwekker Phytophthora infestans die de aardappelziekte veroorzaakt. Samenvatting van het proefschrift van Maita J.M. Latijnhouwers getiteld: 'The role of heterotrimeric G-proteins in development and virulence of Phytophthora infestans'

  4. Voetsporen van evolutie: de dynamiek van effectorgenen in het Phytophthora-genoom

    NARCIS (Netherlands)

    Jiang, R.H.Y.

    2007-01-01

    Het geslacht Phytophthora omvat meer dan 65 verwoestende plantenpathogene soorten die ernstige schade toebrengen aan landbouwgewassen en aan planten, struiken en bomen in de natuur. Economisch belangrijke pathogenen zijn onder andere Phytophthora infestans, de veroorzaker van de aardappelziekte, Phy

  5. FIRST REPORT OF Phytophthora nicotianae CAUSING ROOT ROT OF SOURSOP IN NORTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    JAQUELINE FIGUEREDO DE OLIVEIRA COSTA

    Full Text Available ABSTRACT In 2013, soursop trees showing symptoms of root rot were observed in a field in Maceió, state of Alagoas, Brazil. It was isolated Phytophthora sp. which pathogenicity was confirmed in the host seedlings. Morphological and physiological characteristics in carrot-agar modified medium were consistent with Phytophthora nicotianae description. The PCR sequences products obtained with ITS1/ITS4 primers were compared to sequences of ribosomal DNA of Phytophthora species from the GenBank database observing high identity with other P. nicotianae isolates. A phylogenetic tree was performed to compare the isolate with other sequences of P. nicotianae, which clustering has been verified with 99% of bootstrap, confirming the morphophysiological studies. This is the first report of this pathogen on annonaceous plants in the Northeastern Brazil.

  6. Phytophthora nicotianae diseases worldwide: new knowledge of a long-recognised pathogen

    Directory of Open Access Journals (Sweden)

    Franck PANABIERES

    2016-05-01

    Full Text Available Phytophthora nicotianae was first isolated from tobacco at the end of the 19th century. This organism is now considered as one of the most devastating oomycete plant pathogens, with a recognized host range of more than 255 species over five continents and a wide diversity of climates. The economic losses caused by P. nicotianae are difficult to estimate, because of the diversity of its hosts and ecological niches. For these reasons, this pathogen represents a continuous challenge to plant disease management programmes, which frequently rely solely on the use of chemicals. Phytophthora nicotianae is better adapted than its competitors to abiotic stresses, especially to climate warming. As a result, its importance is increasing. This review illustrates, with some examples, how P. nicotianae currently impacts plant economies worldwide, and how it may constitute more severe threats to agriculture and natural ecosystems in the context of global climate change.

  7. Identification and validation of polymorphic microsatellite loci for the analysis of Phytophthora nicotianae populations

    Science.gov (United States)

    A large number of SSR loci were screened in the genomic assemblies of 14 different isolates of Phytophthora nicotianae and primers were developed for amplification of 17 markers distributed among different contigs. These loci were highly polymorphic and amplified from genetically distant isolates of...

  8. Genetic characterization of Phytophthora nicotianae by the analysis of polymorphic regions of the mitochondrial DNA.

    Science.gov (United States)

    A new method based on the analysis of mitochondrial intergenic regions characterized by intraspecific variation in DNA sequences was developed and applied to the study of the plant pathogen Phytophthora nicotianae. Two regions flanked by genes trny and rns and trnw and cox2 were identified by compa...

  9. Anaerobic soil disinfestation reduces survival and infectivity of Phytophthora nicotianae chlamydospores in pepper

    Science.gov (United States)

    Phytophthora nicotianae is the principal causal agent of root and crown rot disease of pepper plants in Extremadura (western Spain), a spring-summer crop in this region. Preplant soil treatment by anaerobic soil disinfestation (ASD) may effectively control plant pathogens in many crop production sys...

  10. Bescherming van nieuwe groei tegen Phytophthora in de teelt van aardappelen

    NARCIS (Netherlands)

    Kalkdijk, J.R.; Schepers, H.T.A.M.; Evenhuis, A.

    2005-01-01

    Onderzoek naar de werking van fungiciden tijdens de teelt van poot- en consumptieaardappelen. Tijdens de periode dat het loof snel groeit zijn er delen van de plant onbeschermd tegen Phytophthora. De werking van fungiciden op de bescherming van de nieuwe groei is in biotoetsen regelmatig getoetst. E

  11. Spatial analysis of the incidence of Phytophthora infestans (Mont. De Bary and Phytophthora nicotianae Breda de Haan on potato

    Directory of Open Access Journals (Sweden)

    Leónides Castellanos González

    2016-03-01

    Full Text Available The objective of this research was to conduct a spatial analysis of the incidence of Phytophthora nicotianae Breda de Haan and Phytophthora infestans (Mont. De Bary, during five seasons of potato in Fields Company Miscellaneous Crops in Horquita, Cienfuegos (2003-2004 to 2007-2008. Information about pathogens, collected by the Plant Protection Station of Yaguaramas, was used in order to do so. An alpha numerical database was made, oriented to a group of areas under center pivot irrigation machines (Kubans and Bayamón and its quadrants. Parallel to this, mapping of center pivot machines and quadrants was generated in MapInfo GIS 8.5. Several automatic geo codifications were made in order to relate the alphanumeric database and the mapping, and thematic maps were generated in the presence or absence of pathogens. The two study agents have presented high spatial variability during the five planting seasons. Both have influenced the same geographical area with similar appearance date. P. infestans has not expressed a defined dispersion pattern and it has spread at random from the primary source of incidence, while Phytophthora nicotianae has become an endemic agent which shows a dispersion pattern towards neighboring areas or areas connected by the road network from the primary sources, which have been associated with poor land leveling and late or intermediate planting seasons.

  12. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  13. Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere

    OpenAIRE

    Jin, Fengli; Ding, Yanqin; Ding, Wei; Reddy, M. S.; Fernando, W. G. Dilantha; Du,Binghai

    2011-01-01

    The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were i...

  14. Kaliumfosfiet helpt kalanchoë tegen phytophthora (interview met Filip van Noort)

    NARCIS (Netherlands)

    Neefjes, H.; Noort, van F.R.

    2009-01-01

    Toevoegen van plantversterker kaliumfosfiet maakt kalanchoë weerbaar tegen phytophthora. Onderzoek bij WUR Glastuinbouw heeft dit aangetoond in een deel van een proef. De praktijk is voorzichtig met het middel

  15. Multiplex-detectie van Phytophthora: "padlock-based Universal Multiplex detection Array" (pUMA)

    NARCIS (Netherlands)

    Gaszczyk, K.; Mendes, O.; Verstappen, E.C.P.; Bonants, P.J.M.; Schoen, C.D.

    2010-01-01

    Plant Research International heeft een diagnostische methode ontwikkeld die toe te passen is 'in planta', en ook de meest recent beschreven (quarantaine-) soorten omvat. De methode omvat de ontwikkeling van een generieke Phytophthora-methode gevolgd door een Phytophthora-identificatie.

  16. Doseringsverlaging op basis van loof- en knolresistentie tegen Phytophthora infestans in aardappel

    NARCIS (Netherlands)

    Spits, H.G.

    2007-01-01

    Een mogelijkheid om het middelengebruik omlaag te krijgen is een bestrijdingsstrategie te ontwikkelen waarbij de gevoeligheid van het ras gebruikt wordt bij de beheersing van de aardappelziekte. Bij zo’n strategie zou een ras dat weinig gevoelig is voor Phytophthora met een lagere dosering net zo go

  17. Differences in intensity and specificity of hypersensitive response induction in Nicotiana spp. by INF1, INF2A, and INF2B of Phytophthora infestans

    NARCIS (Netherlands)

    Huitema, E.; Vleeshouwers, V.G.A.A.; Cakir, C.; Kamoun, S.; Govers, F.

    2005-01-01

    Elicitins form a family of structurally related proteins that induce the hypersensitive response (HR) in plants, particularly Nicotiana spp. The elicitin family is composed of several classes. Most species of the plant-pathogenic oomycete genus Phytophthora produce the well-characterized 10-kDa

  18. Amino terminal region of Phytophthora sojae cel12 endoglucanase confers tissue collapse function in Nicotiana

    Science.gov (United States)

    Phytophthora encodes an unusually large number of glycosyl hydrolases (GH), with many large gene families resulting from duplication events. There are ten copies of GH 12 (cel12) present in Phytophthora sojae. This is the only pathogen endoglucanase family to which plants produce an inhibitory pr...

  19. Reação de híbridos somáticos de citros à infecção por Phytophthora nicotianae Reaction of citrus somatic hybrids to the infection by Phytophthora nicotianae

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    Meire Menezes Bassan

    2010-06-01

    Full Text Available Este trabalho avaliou a resistência à infecção de tronco e de raízes por Phytophthora nicotianae em híbridos somáticos de citros com potencial para serem utilizados como porta-enxertos. Os híbridos somáticos avaliados foram laranja 'Hamlin' (Citrus sinensis + toranja 'Indian Red' (Citrus grandis (plantas 1 e 2 e laranja 'Hamlin' (C. sinensis + toranja 'Singapura' (C. grandis. Plantas de limão 'Cravo' (Citrus limonia, laranja 'Caipira' (C. sinensis, laranja-azeda (C. aurantium e Poncirus trifoliata 'Davis A' (Poncirus trifoliata foram utilizadas como plantas-controle devido à reação conhecida à infecção pelo patógeno. Avaliações realizadas entre 30 e 60 dias após as inoculações com o patógeno incluíram o comprimento das lesões no tronco e a massa seca do sistema radicular nas plantas avaliadas. O híbrido somático laranja 'Hamlin' + toranja 'Indian Red' (planta 1 mostrou-se tolerante a P. nicotianae, indicando potencial para continuidade nas suas avaliações como porta-enxerto para citros.This study aimed to evaluate the resistance to trunk and root infection by Phytophthora nicotianae in citrus somatic hybrids with potential to be utilized as rootstocks. The somatic hybrids evaluated were 'Hamlin' sweet orange (Citrus sinensis + 'Indian Red' pummelo (Citrus grandis (plants 1 and 2, and 'Hamlin' sweet orange (C. sinensis + 'Singapura' pummelo (C. grandis. Plants of 'Rangpur' lime (Citrus limonia, 'Caipira' sweet orange (C. sinensis, sour orange (C. aurantium, and Poncirus trifoliata 'Davis A' (Poncirus trifoliata were used as control due to their known reaction to the pathogen. Evaluations performed between 30 and 60 days after pathogen inoculation included the length of trunk lesions, and root dry mass of the root system of evaluated plants. The somatic hybrid 'Hamlin' sweet orange + 'Indian Red' pummelo (plant 1 was tolerant to P. nicotianae, indicating potential to be further evaluated as a rootstock.

  20. Simultaneous detection and quantification of Phytophthora nicotianae and P. cactorum, and distribution analyses in strawberry greenhouses by duplex real-time PCR.

    Science.gov (United States)

    Li, Mingzhu; Inada, Minoru; Watanabe, Hideki; Suga, Haruhisa; Kageyama, Koji

    2013-01-01

    Phytophthora nicotianae and P. cactorum cause Phytophthora rot of strawberry. A duplex real-time PCR technique for simultaneous detection and quantification of the two pathogens was developed. Species-specific primers for P. nicotianae and P. cactorum were designed based on the internal transcribed spacer regions (ITS) of rDNA and the ras-related protein gene Ypt1, respectively. TaqMan probes were labeled with FAM for P. nicotianae and HEX for P. cactorum. Specificities were demonstrated using 52 isolates, including various soil-borne pathogens. Sensitivities for P. nicotianae and P. cactorum DNAs were 10 fg and 1 pg, respectively. The technique was applied to naturally infested soil and root samples; the two pathogens were detected and the target DNA concentrations were quantified. Significant correlations of DNA quantities in roots and the surrounding soils were found. The minimum soil DNA concentration predicting the development of disease symptoms was estimated as 20 pg (g soil)(-1). In three strawberry greenhouses examined, the target DNA concentrations ranged from 1 to 1,655 pg (g soil)(-1) for P. nicotianae and from 13 to 233 pg (g soil)(-1) for P. cactorum. The method proved fast and reliable, and provides a useful tool to monitor P. nicotianae and P. cactorum in plants or soils.

  1. Genetic analysis of Phytophthora nicotianae populations from different hosts using microsatellite markers

    Science.gov (United States)

    Two hundred thirty-one isolates of P. nicotianae representing 14 populations from different host genera, including agricultural crops (Citrus, Nicotiana, and Lycopersicon), potted ornamental species in nurseries (Lavandula, Convolvulus, Myrtus, Correa and Ruta) and other plant genera of lesser econo...

  2. Macrocyclic Trichothecenes from Myrothecium roridum Strain M10 with Motility Inhibitory and Zoosporicidal Activities against Phytophthora nicotianae.

    Science.gov (United States)

    Mondol, Muhammad Abdul Mojid; Surovy, Musrat Zahan; Islam, M Tofazzal; Schüffler, Anja; Laatsch, Hartmut

    2015-10-14

    The cytotoxicity of the extract obtained from Myrothecium roridum M10 and a characteristic (1)H signal at δH ∼8 led to the assumption that verrucarin/roridin-type compounds were present. Upscaling on rice medium led to the isolation of four new metabolites: verrucarins Y (1) and Z (6) (macrocyclic trichothecenes), bilain D (12) (a diketopiperazine derivative), and hamavellone C (14) (an unusual cyclopropyl diketone). In addition, nine known trichothecenes [verrucarin A (3), 16-hydroxyverrucarin A (5), verrucarin B (7), 16-hydroxyverrucarin B (8), verrucarin J (2), verrucarin X (4), roridin A (9), roridin L-2 (10), and trichoverritone (11)] and a bicyclic lactone [myrotheciumone A (15)] were identified. Their structures and configurations were determined by spectroscopic methods, published data, Mosher's method, and considering biosyntheses. Some trichothecenes showed motility inhibition followed by lysis of the zoospores against devastating Phytophthora nicotianae within 5 min. Compounds 2, 3, 7, and 9 also exhibited potent activities against Candida albicans and Mucor miehei.

  3. 烟草黑胫病菌对农田草本植物的寄主范围%The host range of Phytophthora nicotianae var. nicotianae in field herbs

    Institute of Scientific and Technical Information of China (English)

    马国胜; 高智谋

    2011-01-01

    烟草黑胫病是烟草生产中的重要病害,对烟草的产量和质量均影响极大[1-2]。烟草黑胫病菌Phytophthora nicotianae var.nicotianae(Breda deHaan)Tucker是引起烟草黑胫病的唯一病原菌,以往的研究均认为,

  4. Recognition of an Avr3a homologue plays a major role in mediating nonhost resistance to Phytophthora capsici in Nicotiana species.

    Science.gov (United States)

    Vega-Arreguín, Julio C; Jalloh, Abubakar; Bos, Jorunn I; Moffett, Peter

    2014-08-01

    Nonhost resistance is a commonly occurring phenomenon wherein all accessions or cultivars of a plant species are resistant to all strains of a pathogen species and is likely the manifestation of multiple molecular mechanisms. Phytophthora capsici is a soil-borne oomycete that causes Phytophthora blight disease in many solanaceous and cucurbitaceous plants worldwide. Interest in P. capsici has increased considerably with the sequencing of its genome and its increasing occurrence in multiple crops. However, molecular interactions between P. capsici and both its hosts and its nonhosts are poorly defined. We show here that tobacco (Nicotiana tabacum) acts like a nonhost for P. capsici and responds to P. capsici infection with a hypersensitive response (HR). Furthermore, we have found that a P. capsici Avr3a-like gene (PcAvr3a1) encoding a putative RXLR effector protein produces a HR upon transient expression in tobacco and several other Nicotiana species. This HR response correlated with resistance in 19 of 23 Nicotiana species and accessions tested, and knock-down of PcAvr3a1 expression by host-induced gene silencing allowed infection of resistant tobacco. Our results suggest that many Nicotiana species have the capacity to recognize PcAvr3a1 via the products of endogenous disease resistance (R) genes and that this R gene-mediated response is a major component of nonhost resistance to P. capsici.

  5. Invloed van minerale olie op de bestrijding van Phytophthora infestans in pootaardappelen

    NARCIS (Netherlands)

    Spits, H.G.; Bus, C.B.

    2003-01-01

    De invloed van toevoeging van olie aan een fungicide op de werking van het fungicide is afhankelijk van het gebruikte fungicide. Gezamenlijk spuiten van olie en Aviso DF, Curzate M en mogelijk ook Acrobat, verhoogt de curatieve werking van deze fungiciden. Gezamenlijk spuiten van olie en Aviso DF, l

  6. The dihydrolipoyl acyltransferase gene BCE2 participates in basal resistance against Phytophthora infestans in potato and Nicotiana benthamiana.

    Science.gov (United States)

    Wang, Hongyang; Sun, Chunlian; Jiang, Rui; He, Qin; Yang, Yu; Tian, Zhejuan; Tian, Zhendong; Xie, Conghua

    2014-07-01

    Dihydrolipoyl acyltransferase (EC 2.3.1.12), a branched-chain α-ketoacid dehydrogenase E2 subunit (BCE2), catalyzes the transfer of the acyl group from the lipoyl moiety to coenzyme A. However, the role of BCE2 responding to biotic stress in plant is not clear. In this study, we cloned and characterized a BCE2 gene from potato, namely StBCE2, which was previously suggested to be involved in Phytophthora infestans-potato interaction. We found that the expression of StBCE2 was strongly induced by both P. infestans isolate HB09-14-2 and salicylic acid. Besides, when the homolog of StBCE2 in Nicotiana benthamiana named NbBCE2 was silenced, plants showed increased susceptibility to P. infestans and reduced accumulation of hydrogen peroxide (H2O2). Furthermore, we found that a marker gene NbrbohB involved in the production of reactive oxygen species, was also suppressed in NbBCE2-silenced plants. However, silencing of NbBCE2 had no significant effect on the hypersensitive responses trigged by INF1, R3a-AVR3a(KI) pair or Rpi-vnt1.1-AVR-vnt1.1 pair. Our results suggest that BCE2 is associated with the basal resistance to P. infestans by regulating H2O2 production.

  7. Relationship of microbial communities and suppressiveness of Trichoderma fortified composts for pepper seedlings infected by Phytophthora nicotianae.

    Science.gov (United States)

    Ros, Margarita; Raut, Iulia; Santisima-Trinidad, Ana Belén; Pascual, Jose Antonio

    2017-01-01

    The understanding of the dynamic of soil-borne diseases is related to the microbial composition of the rhizosphere which is the key to progress in the field of biological control. Trichoderma spp. is commonly used as a biological control agent. The use of next generation sequencing approaches and quantitative PCR are two successful approaches to assess the effect of using compost as substrate fortified with two Trichoderma strains (Trichoderma harzianum or Trichoderma asperellum) on bacterial and fungal communities in pepper rhizosphere infected with Phytophthora nicotianae. The results showed changes in the bacterial rhizosphere community not attributed to the Trichoderma strain, but to the pathogen infection, while, fungi were not affected by pathogen infection and depended on the type of substrate. The Trichoderma asperellum fortified compost was the most effective combination against the pathogen. This could indicate that the effect of fortified composts is greater than compost itself and the biocontrol effect should be attributed to the Trichoderma strains rather than the compost microbiota, although some microorganisms could help with the biocontrol effect.

  8. Lofar Agro : gewasmonitoring en microklimaatmodellering ten behoeve van plaatsspecifieke beheersing van Phytophthora infestans : microklimaat en Phytophthora infectierisico's

    NARCIS (Netherlands)

    Kessel, G.J.T.

    2009-01-01

    In de zomer van 2008 is het microklimaat in aardappel op twee plaatsen in Nederland zeer gedetailleerd gemeten. Deze meetsessies hebben unieke datasets opgeleverd m.b.t. het microklimaat in een aardappelgewas en de invloed daarop van de hoeveelheid loofmassa, de plaats en de hoogte in het gewas

  9. 烟草黑胫病菌产孢性状的研究%Study on the Producing Spores Properties of Phytophthora Parasitica var nicotianae

    Institute of Scientific and Technical Information of China (English)

    周志成

    2005-01-01

    研究了湖南烟区烟草黑胫病菌(Phytophthora parasitica var nicotianae)分离菌株的产孢性状.结果表明,Py96-1和Py96-2两菌株用燕麦片培养基,在25~28℃温度下,培养21~28 d,产孢菌丝生长最好,菌丝茂密,产生孢子囊多.

  10. Silencing of DS2 aminoacylase-like genes confirms basal resistance to Phytophthora infestans in Nicotiana benthamiana.

    Science.gov (United States)

    Nakano, Masahito; Nishihara, Masahiro; Yoshioka, Hirofumi; Ohnishi, Kouhei; Hikichi, Yasufumi; Kiba, Akinori

    2014-01-01

    Nicotiana benthamiana is a potential host to several plant pathogens, and immature leaves of N. benthamiana are susceptible to Phytophthora infestans. In contrast, mature leaves of N. benthamiana are weakly susceptible and show basal resistance to P. infestans. We screened a gene-silenced mature plant showing high resistance to P. infestans, designated as DS2 (Disease suppression 2). The deduced amino acid sequence of cDNA responsible for DS2 encoded a putative aminoacylase. Growth of P. infestans decreased in DS2 plants. Trypan blue staining revealed inhibited hyphae growth of P. infestans with an increased number of dead cells under the penetration site in DS2 plants. Consistent with growth inhibition of P. infestans, defense responses such as reactive oxygen generation and expression of a salicylic acid-dependent PR-1a increased markedly in DS2 plants compared with that of control plants. DS2 phenotype was compromised in NahG plants, suggesting DS2 phenotype depends on the salicylic acid signaling pathway. Accelerated defense response was observed in DS2 plants elicited by INF1 elicitin as well as by NbMEK2(DD), which is the constitutive active form of NbMEK2, and act as a downstream regulator of INF1 perception. On the other hand, INF1- and NbMEK2(DD)-induced defense responses were prevented by DS2-overexpressing transgenic tobacco. These results suggest that DS2 negatively regulates plant defense responses against P. infestans via NbMEK2 and SA-dependent signaling pathway in N. benthamiana.

  11. Study on the Cultural Characteristics of Phytophthora parasitica var. nicotianae%烟草黑胫病菌培养特性的研究

    Institute of Scientific and Technical Information of China (English)

    张文友; 刘铭; 尹福强; 赵云飞; 刘朝科

    2013-01-01

    研究了采自攀西地区的烟草黑胫病菌在不同培养基、不同温度及不同pH值等条件下培养特性。结果表明:烟草黑胫病菌最适合在燕麦培养基上生长,菌丝生长快。菌丝在20~36℃都能生长,28℃生长最佳。在不同pH值的培养基培养下,菌丝最适合在pH值为5.5的培养基上生长。%Phytophthora parasitica var.nicotianae was cultivated under the conditions of different cultural media ,pH value and temperature ,then observed its growth status and morphological characteristics.The results showed that oatmeal agar was most suitable for the growth of the strains of P. Nicotianae.The hyphae can grow at 20~36℃,the temperature of 28℃and the pH value of 5.5 were the best for the growth of the strains of P.Nicotianae.

  12. The receptor-like kinase SERK3/BAK1 is required for basal resistance against the late blight pathogen phytophthora infestans in Nicotiana benthamiana.

    Directory of Open Access Journals (Sweden)

    Angela Chaparro-Garcia

    Full Text Available BACKGROUND: The filamentous oomycete plant pathogen Phytophthora infestans causes late blight, an economically important disease, on members of the nightshade family (Solanaceae, such as the crop plants potato and tomato. The related plant Nicotiana benthamiana is a model system to study plant-pathogen interactions, and the susceptibility of N. benthamiana to Phytophthora species varies from susceptible to resistant. Little is known about the extent to which plant basal immunity, mediated by membrane receptors that recognise conserved pathogen-associated molecular patterns (PAMPs, contributes to P. infestans resistance. PRINCIPAL FINDINGS: We found that different species of Phytophthora have varying degrees of virulence on N. benthamiana ranging from avirulence (incompatible interaction to moderate virulence through to full aggressiveness. The leucine-rich repeat receptor-like kinase (LRR-RLK BAK1/SERK3 is a major modulator of PAMP-triggered immunity (PTI in Arabidopsis thaliana and N. benthamiana. We cloned two NbSerk3 homologs, NbSerk3A and NbSerk3B, from N. benthamiana based on sequence similarity to the A. thaliana gene. N. benthamiana plants silenced for NbSerk3 showed markedly enhanced susceptibility to P. infestans infection but were not altered in resistance to Phytophthora mirabilis, a sister species of P. infestans that specializes on a different host plant. Furthermore, silencing of NbSerk3 reduced the cell death response triggered by the INF1, a secreted P. infestans protein with features of PAMPs. CONCLUSIONS/SIGNIFICANCE: We demonstrated that N. benthamiana NbSERK3 significantly contributes to resistance to P. infestans and regulates the immune responses triggered by the P. infestans PAMP protein INF1. In the future, the identification of novel surface receptors that associate with NbSERK3A and/or NbSERK3B should lead to the identification of new receptors that mediate recognition of oomycete PAMPs, such as INF1.

  13. 烟草疫霉分离及生长培养基的选择%Selection of Isolating and Culturing Medium for Phytophthora nicotianae

    Institute of Scientific and Technical Information of China (English)

    苏凯; 桑维钧; 张新强; 王慧

    2013-01-01

    Different base medium adding different combination of antibiotics were applied for isolation and culture of Phytophthora nicotianae.The results showed that selective medium with Vs base medium (100mL/L V8juice+0.02 g/L CaCO3+2 g/Lagar) adding 10 mg/mL ampicillin +5 mg/mL nysfungin+5 mg/mL carbendazim had the best isolation effect as the successful isolation rate was 100%,and the hypha grew well on this medium.After separation,the hypha could be cultured in Vs base medium as the hypha was white,tight and strong with big bacteria clone and strong growth potential.%采用不同的基本培养基添加抗生素组合对烟草疫霉(Phytophthora nicotianae)进行分离培养.结果表明,以V8培养基(100 mL/L Vs汁+0.02 g/L CaCO3+2 g/L洋菜)为基本培养基附加10 mg/mL氨苄青霉素+5 mg/mL制霉素+5 mg/mL多菌灵的选择培养基分离烟草疫霉的效果较好,分离成功率达100%,菌丝的生长状态也较好.菌丝分离后在V8基本培养基中培养,菌丝紧密、浓白、粗壮,菌落大、长势旺.

  14. Non-host Plant Resistance against Phytophthora capsici Is Mediated in Part by Members of the I2 R Gene Family in Nicotiana spp.

    Science.gov (United States)

    Vega-Arreguín, Julio C.; Shimada-Beltrán, Harumi; Sevillano-Serrano, Jacobo; Moffett, Peter

    2017-01-01

    The identification of host genes associated with resistance to Phytophthora capsici is crucial to developing strategies of control against this oomycete pathogen. Since there are few sources of resistance to P. capsici in crop plants, non-host plants represent a promising source of resistance genes as well as excellent models to study P. capsici – plant interactions. We have previously shown that non-host resistance to P. capsici in Nicotiana spp. is mediated by the recognition of a specific P. capsici effector protein, PcAvr3a1 in a manner that suggests the involvement of a cognate disease resistance (R) genes. Here, we have used virus-induced gene silencing (VIGS) and transgenic tobacco plants expressing dsRNA in Nicotiana spp. to identify candidate R genes that mediate non-host resistance to P. capsici. Silencing of members of the I2 multigene family in the partially resistant plant N. edwardsonii and in the resistant N. tabacum resulted in compromised resistance to P. capsici. VIGS of two other components required for R gene-mediated resistance, EDS1 and SGT1, also enhanced susceptibility to P. capsici in N. edwardsonii, as well as in the susceptible plants N. benthamiana and N. clevelandii. The silencing of I2 family members in N. tabacum also compromised the recognition of PcAvr3a1. These results indicate that in this case, non-host resistance is mediated by the same components normally associated with race-specific resistance. PMID:28261255

  15. Vroegtijdig Phytophthora opsporen met biosensor

    NARCIS (Netherlands)

    Jansen, R.M.C.

    2003-01-01

    Phytophthora kan vroegtijdig worden opgespoord met biosensoren. Bij de Leerstoelgroep Agrarische Bedrijfstechnologie van Wageningen Universiteit wordt verder gekeken naar praktische toepassingen van deze techniek

  16. 西葫芦根腐病病原菌(Phytophthora nicotianae)的生物学特性研究%The Biological characteristic of the root rot disease of summer squash pathogen Phytophthora nicotianae

    Institute of Scientific and Technical Information of China (English)

    李蕊倩

    2008-01-01

    烟草疫霉菌Phytophthora nicotianare是山西省西葫芦根腐病的主要病原,采用致病菌的室内培养方法研究了西葫芦根腐病病原烟草疫霉菌.结果表明,菌丝生长和产生孢子囊的最适温度27℃,最适pH 6,最适培养基为燕麦培养基.黑暗不利于烟草疫霉产生孢子囊.

  17. A Field Experiment on Control Effects of Six Chemicals on Vanilla Phytophthora nicotianae%6种药剂防治香草兰疫病田间药效试验

    Institute of Scientific and Technical Information of China (English)

    刘爱勤; 桑利伟; 孙世伟; 苟亚峰; 刘向阳

    2012-01-01

    The control effects of six chemicals 68% Metalaxyl-M mancozeb WDG, 50% dimethomorph WP, 25% metalaxyl propamocarb WP, 69% dimethomorph mancozeb WP, 36% cymoxanil mancozeb WP and 70% Aliette Mn .Zn WP on Phytophthora nicotianae in vanilla were tested using field experiment. The results showed that 68% Metalaxyl-M mancozeb WDG, 50% dimethomorph WP and 25% metalaxyl propamocarb WP had better control effect to vanilla Phytophthora nicotianae. Three of them could be applied alternately to control Phytophthora nicotianae in vanilla production.%为筛选出防治香草兰疫病的最佳药剂,采用田间小区试验方法.测定68%精甲霜·锰锌WDG(水份散粒剂)、50%烯酰吗啉WP(可湿性粉剂)、25%甲霜·霜霉威WP、69%烯酰吗啉·锰锌WP、36%霜脲锰锌WP和70%乙磷铝锰锌WP等6种不同使用浓度药剂对香草兰疫病的防治效果。结果表明:68%精甲霜·锰锌WDG1000倍液、50%烯酰吗啉WP1000倍液及36%霜脲锰锌WP1000倍液对香草兰疫病大田防效较好。分别为86.6%、81.4%和79.8%。生产上可交替使用这3种药剂来防治香草兰疫病。

  18. Nicotiana benthamiana calreticulin 3a is required for the ethylene-mediated production of phytoalexins and disease resistance against oomycete pathogen Phytophthora infestans.

    Science.gov (United States)

    Matsukawa, Mizuki; Shibata, Yusuke; Ohtsu, Mina; Mizutani, Aki; Mori, Hitoshi; Wang, Ping; Ojika, Makoto; Kawakita, Kazuhito; Takemoto, Daigo

    2013-08-01

    Mature Nicotiana benthamiana shows strong resistance to the potato late blight pathogen Phytophthora infestans. By screening using virus-induced random gene silencing, we isolated a gene for plant-specific calreticulin NbCRT3a as a required gene for resistance of N. benthamiana against P. infestans. NbCRT3a encodes an endoplasmic reticulum quality-control (ERQC) chaperone for the maturation of glycoproteins, including glycosylated cell-surface receptors. NbCRT3a-silenced plants showed no detectable growth defects but resistance to P. infestans was significantly compromised. Defense responses induced by the treatment with INF1 (a secretory protein of P. infestans), such as production of reactive oxygen species and accumulation of phytoalexins, were suppressed in NbCRT3a-silenced N. benthamiana. Expression of an ethylene-regulated gene for phytoalexin biosynthesis, NbEAS, was reduced in NbCRT3a-silenced plants, whereas the expression of salicylic acid-regulated NbPR-1a was not affected. Consistently, induction of ethylene production by INF1 was suppressed in NbCRT3a-silenced plants. Resistance reactions induced by a hyphal wall components elicitor prepared from P. infestans were also impaired in NbCRT3a-silenced plants. However, cell death induced by active mitogen-activated protein kinase kinase (NbMEK2(DD)) was not affected by the silencing of NbCRT3a. Thus, NbCRT3a is required for the initiation of resistance reactions of N. benthamiana in response to elicitor molecules derived from P. infestans.

  19. 烟草黑胫病菌拮抗细菌的筛选与鉴定%Screening and Identification of Antagonistic Bacteria Against Phytophthora parasitica var. nicotianae

    Institute of Scientific and Technical Information of China (English)

    王栋; 伏晓; 韩新宇; 罗定棋; 何余勇; 张永辉; 雷晓

    2012-01-01

    Totally 107 bacterial strains were isolated from different tobacco rhizosphere soils,of which 13 strains showed antagonistic activity against phytophthora parasitica var.nicotianae.LZ-7 strain had the best room flat antibacterial activity and inhibition zone diameter reached 27.82 mm.Pot experiment showed that the LZ-7 and A3 had better control effect which reached 59.12% and 55.84%.The 16S rDNA fragment was amplified from strain LZ-7 by PCR,and the 16S rDNA sequence analysis indicated that strain LZ-7 shared 99% 16S rDNA sequence homology with Bacillus pumilus.In the phylogenetic framework of bacterial classification,LZ-7 belonged to Bacillus pumilus.%从烟草根际土壤分离到107个细菌分离物,通过室内平板对峙培养筛选,筛选到13株对烟草黑胫病菌有拮抗作用的菌株,其中,LZ-7菌株的室内平板抑菌效果最好,抑菌圈直径达27.82 mm。经盆栽试验,LZ-7、A3控病作用较好,防治效果分别达59.12%和55.84%。通过16 S rDNA序列测定与分析,LZ-7与Bacillus pumilus的同源性为99%,初步鉴定证明该菌株属于短小芽孢杆菌。

  20. Variation in Phytophthora infestans: sources and implications

    NARCIS (Netherlands)

    Flier, W.G.

    2002-01-01

    Uitgebreide samenvatting van de dissertatie van Wilbert G. Flier over de oömyceet Phytophthora infestans (Monst.) de Bary, de veroorzaker van 'het kwaad' ofwel de aardappelziekte in de teelt van aardappelen en tomaten

  1. Phytophthora nicotianae var. nicotianae on tomatoes

    NARCIS (Netherlands)

    Weststeijn, G.

    1973-01-01

    Around 1960 some disorders which initially were considered to be of a physiological nature were found in tomato plants grown in glasshouses in the Netherlands. One complex of symptoms was a brown rot of the lateral roots and the tap root, often followed by decomposition of the stem base ti

  2. Phytophthora nicotianae var. nicotianae on tomatoes

    NARCIS (Netherlands)

    Weststeijn, G.

    1973-01-01

    Around 1960 some disorders which initially were considered to be of a physiological nature were found in tomato plants grown in glasshouses in the Netherlands. One complex of symptoms was a brown rot of the lateral roots and the tap root, often followed by decomposition of the stem base tissue and d

  3. Phytophthora nicotianae var. nicotianae on tomatoes

    NARCIS (Netherlands)

    Weststeijn, G.

    1973-01-01

    Around 1960 some disorders which initially were considered to be of a physiological nature were found in tomato plants grown in glasshouses in the Netherlands. One complex of symptoms was a brown rot of the lateral roots and the tap root, often followed by decomposition of the stem base

  4. Het koor van adviseurs verdient een dirigent. Over kennisverspreiding rond Phytophthora in aardappelen2011

    NARCIS (Netherlands)

    Buurma, J.S.; Janssens, S.R.M.

    2011-01-01

    In dit werkdocument wordt verslag gedaan van een sociologisch onderzoek naar de kennisverspreiding rond Phytopthora in aardappelen. We beschrijven welke onderwerpen en welke partijen bij de kennisverspreiding zijn betrokken, welke partijen zich met welke onderwerpen bezig houden en welke argumenten

  5. Narrow-Leafed Lupin (Lupinus angustifolius) β1- and β6-Conglutin Proteins Exhibit Antifungal Activity, Protecting Plants against Necrotrophic Pathogen Induced Damage from Sclerotinia sclerotiorum and Phytophthora nicotianae

    Science.gov (United States)

    Jimenez-Lopez, Jose C.; Melser, Su; DeBoer, Kathleen; Thatcher, Louise F.; Kamphuis, Lars G.; Foley, Rhonda C.; Singh, Karam B.

    2016-01-01

    Vicilins (7S globulins) are seed storage proteins and constitute the main protein family in legume seeds, particularly in narrow-leafed lupin (Lupinus angustifolius L.; NLL), where seven vicilin genes, called β1- to β7-conglutin have been identified. Vicilins are involved in germination processes supplying amino acids for seedling growth and plant development, as well as in some cases roles in plant defense and protection against pathogens. The roles of NLL β-conglutins in plant defense are unknown. Here the potential role of five NLL β-conglutin family members in protection against necrotrophic fungal pathogens was investigated and it was demonstrated that recombinant purified 6xHis-tagged β1- and β6-conglutin proteins exhibited the strongest in vitro growth inhibitory activity against a range of necrotrophic fungal pathogens compared to β2, β3, and β4 conglutins. To examine activity in vivo, two representative necrotrophic pathogens, the fungus Sclerotinia sclerotiorum and oomycete Phytophthora nicotianae were used. Transient expression of β1- and β6-conglutin proteins in Nicotiana benthamiana leaves demonstrated in vivo growth suppression of both of these pathogens, resulting in low percentages of hyphal growth and elongation in comparison to control treated leaves. Cellular studies using β1- and β6-GFP fusion proteins showed these conglutins localized to the cell surface including plasmodesmata. Analysis of cellular death following S. sclerotiorum or P. nicotianae revealed both β1- and β6-conglutins suppressed pathogen induced cell death in planta and prevented pathogen induced suppression of the plant oxidative burst as determined by protein oxidation in infected compared to mock-inoculated leaves. PMID:28018392

  6. Waarschuwingssystemen Phytophthora in aardappelen : vergelijking van vier systemen met een praktijk-spuitschema

    NARCIS (Netherlands)

    Spits, H.G.; Wander, J.G.N.

    2000-01-01

    Gegevens in bijgaande tabellen: 1) Overzicht algemene proefveldgegevens per locatie (2000); 2) Aantal bespuitingen (preventief/ curatief) per locatie in 1999; 3) Datum eerste bespuiting van de vier waarschuwingssystemen per locatie in 2000; 4) Aantal bespuitingen (Shirlan, Curzate M en Tattoo C) kg

  7. Phytophthora infestans, een dynamische ziekteverwekker

    NARCIS (Netherlands)

    Govers, F.

    2010-01-01

    Samenvatting van de inaugurele rede van Francine Govers op 11 juni 2009. Dit artikel beschrijft de stand van zaken in het onderzoek aan oömyceten en in het bijzonder aan Phytophthora infestans, de veroorzaker van de aardappelziekte. Er wordt ingegaan op ziektebestrijding en resistentieveredeling, de

  8. 柠檬草精油对烟草黑胫病的抑制活性研究%Antimicrobial Activities of Lemongrass Essential Oil Against Phytophthora parasitica var.nicotianae

    Institute of Scientific and Technical Information of China (English)

    卢敏; 韩智强; 李忠环; 詹莜国; 彭云; 徐云; 姚雷

    2012-01-01

    研究了5种常见植物精油的抗烟草黑胫病活性,确定了植物精油的种类与浓度,为烟草黑胫病防治的精油药剂的开发与应用提供理论依据.采用菌丝生长抑制法和茎秆接种法,分别评价了植物精油对烟草黑胫病的体外和体内抑菌活性.结果表明,在体外条件下,柠檬草精油对烟草黑胫病的抑制效果最好,具有浓度梯度抑制效应,最低抑菌浓度为320 μg/mL;在体内条件下,柠檬草精油640μg/mL时对烟草黑胫病预防与治疗效果最佳,病情指数分别为16.67和56.79,相对诱导效果分别为81.93%和38.44%,与甲霜灵190 μg/mL无显著性差异.柠檬草精油具有优越的体外和体内抗菌活性,是有潜力的生物抗菌剂和杀菌剂,有望在今后的烟草黑胫病菌防治中进一步开发利用.%Antimicrobial activities of five common plant essential oils against Phytophthora parasitica var. Nicotianae were investigated,and the species and concentration of the plant essential oils were determined, which provided a theory basis for the development and application of essential oil fungicide against P. Parasitica var. Nicotianae. Hypha growth inhibition assay and stem inoculation method were used to evaluate the in vitro and in vivo antimicrobial activity of essential oils to P. Parasitica var. Nicotianae. The results showed that, in the selected five essential oils, lemongrass essential oil was most effective against P. Parasitica var. Nicotianae in vitro which inhibited hypha growth in a dose-dependent manner, and totally inhibited mycelia growth with a minimum concentration of 320 μg/mL. In vivo, 640 μg/mL of lemongrass essential oil was most efficient for prevention and treatment of disease with a disease index of 16.67 and 56. 79 and relatively induced efficiency of 81. 93% and 38. 44 %, respectively. No significant difference was found between 640μg/mL of lemongrass essential oil and 190 μg/mL of metalaxyl. This study has demonstrated

  9. 荧光假单胞菌拮抗菌株对烟草疫霉的抑菌机制及控病效果%Antagonistic mechanism of Pseudomonas fluorescens strains against Phytophthora nicotianae and biocontrol effect on tobacco black shank

    Institute of Scientific and Technical Information of China (English)

    董国菊; 马冠华; 肖崇刚

    2012-01-01

    To explore the antagonistic mechanism of rhizospheric bacteria against Phytophthora nicotianae van Breda de Haan,five antagonistic Pseudomonas fluorescens strains were isolated from rhizospheric soils of tobacco fields in Chongqing.Efficient antagonistic strain against P.nicotianae was screened using dual culture technique and metabolites inhibitory test.Among these strains,P-72-10 showed the highest suppressive effect;it produced an inhibition zone of 13.0mm(radius) and an inhibitory rate at 68.57%.Furthermore,the growth of pathogen's hypha was also suppressed by the extracellular metabolites of strain P-72-10 from 25.39% to 46.03%.P.nicotianae was observed microscopically excessive branching of mycelia and malformation of mycelia tips;thick-walled cells with concentrated plasmas and chlamydospore-like cells.When tested on the tobacco plants grown in greenhouse,strain P-72-10 got a good biocontrol effect on tobacco black shank infection and effects on the resistant and susceptible varieties of tobacco were 53.57% and 66.37% respectively.%为探讨烟草根际生防细菌对烟草疫霉Phytophthora nicotianae的抑菌机制,从重庆地区连作烟田健康烟株根际土壤分离获得5株荧光假单胞菌Pseudomonas fluorescens拮抗菌株。通过平板对峙及代谢产物抑菌试验筛选对烟草疫霉具有高效拮抗作用的菌株,其中,P-72-10菌株抑菌效果最强,抑菌带半径达13.0 mm,相对抑制率为68.57%,且该菌株代谢产物对烟草疫霉菌丝生长有明显的抑制作用,相对抑制率达25.39%~46.03%;显微观察发现该菌株可引起烟草疫霉菌丝的分支增多,菌丝顶端膨大呈畸形,多数菌丝中间或顶端细胞的细胞壁加厚、原生质浓缩和产生类似厚壁孢子的细胞。在温室盆栽条件下P-72-10菌株对烟草黑胫病也表现出良好的控病效果,对抗病和感病品种的相对防效分别为53.57%和66.37%。

  10. Different Conditions on the Cultural Characteristics of Race O of Phytophthora Parasitica var.nicotianae%烟草黑胫病菌0号生理小种不同条件下培养特性的研究

    Institute of Scientific and Technical Information of China (English)

    苏振刚; 王静; 周佳; 李锡冲; 郑林林; 李元元; 赵百英; 杨帆; 王元英

    2011-01-01

    The cultural characteristics of race 0 of Phytophthora parasitica var.nicotianae were investigated in order to provide more basic information for further study and integrated management of the disease.The study used several cultural factors, including experimental medium, light, bacteria age, inducing agents and induction time to observe cultural characteristics of race 0 of Phytophthora parasitica var.nicotianae, such as growth rate of tobacco, sporangium production and tour dynamic spores release etc.The results showed that Oatmeal medium was suitable for mycelium growth and production of sporangium; light could limit its growth; based on the experimental period and other factors, mycelium cultivated for 21 days is more appropriate for induced; 0.1%KNO3 solution soaking mycelium contribute to sporangium production; after 72 h cultivation by 26℃, sudden drop of 12℃ for 0.5 h,combine with 1% glucose solution can promote sporangia to release zoospores, and it can also prolong time of zoospore's activities.%研究了烟草黑胫病菌0号生理小种的若干培养性状,为进一步展开与之相关的研究和综合防治提供理论基础.用培养基、光照、菌龄、诱导剂和诱导时间等不同因素研究了对烟草黑胫病菌0号生理小种的生长速度、产孢量和游动孢子释放量等方面的影响.结果表明,燕麦培养基较适于其生长和产生孢子囊,光照限制其生长;在本实验周期内,培养21 d的菌丝较适宜诱导,0.1 % KNO_3溶液浸泡菌丝有助于孢子囊的产生;经26℃培养72 h后,突降12℃处理0.5 h,结合1%葡萄糖溶液可促使抱子囊释放游动孢子,并延长后者的活动时间.

  11. Induced resistance of tobacco to Phytophthora nicotianae by synthetic oligosaccharides%化学合成寡糖诱导烟草抗黑胫病的初步研究

    Institute of Scientific and Technical Information of China (English)

    朱振元; 张勇民; 徐同

    2004-01-01

    抑菌测定和盆栽试验表明:化学合成的Lewisx和Lewisa寡糖对烟草黑胫病病原菌菌丝生长无明显影响;Lewisx五糖和七糖处理烟草,可使烟草植株产生对黑胫病菌(Phytophthora nicotianae)的抗性,在处理浓度0~10μg/mL内,随着浓度增高诱导效果增强,当浓度达10μg/mL时,诱导防病效果达90%以上.Lewisx七糖处理,可导致烟草叶片过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸裂解酶(PAL)等防卫酶活性不同程度地提高,PPO、POD及PAL分别在处理后第4d、第6 d和第8 d达到最大值,比对照分别增加了70.7%、150.0%和142.8%.

  12. 防治烟草黑胫病的根际细菌分离与筛选%Isolation of tobacco rhizobacteria and their antagonism to Phytophthora parasitica. Var.nicotiana

    Institute of Scientific and Technical Information of China (English)

    顾金刚; 方敦煌; 李天飞; 刘杏忠

    2001-01-01

    从云南昆明、玉溪、曲靖、楚雄、大理等地13份烟田根际土样中,经分离纯化得到753株根际细菌.通过对黑胫病病原(Phytophthora parasitica.var.nicotiana)的平板拮抗筛选,共得到有抑制病原菌生长的根际细菌97株,用细菌悬液浸泡烟草种子,通过测定烟草种子发芽率和对烟草苗期的促生作用,选出有较好促生作用的细菌19株,再进行温室盆栽测定,选出对烟草黑胫病有防病促生作用的根际细菌6株,分别编号为RB-1、R4、RB-42、RB-59、RB-78、RB-89.在研究过程中发现,从明胶、几丁质培养基和从根表上分离到的细菌,其防病促生作用的机率较高.在防治苗期黑胫病的温室试验中,RB-42和RB-89菌株的相对防治效果分别达到42.22%和37.78%.通过形态学与生理生化初步的鉴定,RB-42、RB-78、RB-89鉴定为假单胞杆菌(Pseudomonas spp.),R4鉴定为芽孢杆菌(Bacillus sp.).

  13. Internetprogramma geeft inzicht in eigen Phytophthora-strategie. (Internet site gives insight in effectiveness of growers personal potato late blight control strategies)

    NARCIS (Netherlands)

    Kessel, G.J.T.; Hanse, L.

    2005-01-01

    Om telers te helpen met hun bestrijdingsstrategie is het Agrobiocon programma 'Visualisatie infectie Phytophthora' ontwikkeld. Uitleg van mede ontwikkelaar Geert Kessel van Plant Research International van Wageningen UR

  14. 烟草疫霉拮抗菌株P-72-10的鉴定及其拮抗代谢产物初步分析%Identification and characterization of antagonistic bacterial strain P-72-10 against Phytophthora nicotianae

    Institute of Scientific and Technical Information of China (English)

    董国菊; 李文英; 刘翠平; 周常勇; 肖崇刚

    2012-01-01

    Tobacco black shank, caused by Phytophthora nicotianae van Breda de Haan, is one of economically important disease of tobacco production. In the previous study, a strain P-72-10 was isolated from the healthy tobacco in the rhizosphere soil of Chongqing. It was selected based on its strong antagonistic activity a-gainst P. nicotianae on the plate dual-culture test and its ability to suppress tobacco black shank disease effectively in the greenhouse condition. In the study, the phylogeny of P-72-10 was analyzed, and its taxonomic position was identified using morphological and chemotaxonomic characteristics, together with 16S rDNA gene phylogenetic analysis. The colonies were cream in color on KB culture. Cells were gram-negative, rod-shaped [ (8.1 -16.2)(i,m x (1.8 -4.8) jun], motile owing to one or several polar flagella and did not form endo-spores. The growth temperature for P-72-10 ranged from 4 to 401 with the optimum at 28 -30t. The results of BIOLOG GN2 showed that P-72-10 belonged to Pseudomonas. The genomic (G +C) content was 60.72%. Phylogenetic analysis of the 16SrDNA gene sequence revealed that P-72-10 was the most closely related to P. fluorescens, with the sequence similarity of 99%. Nucleotide number of the accession was HQ888871. Taxo-nomically, strain P-72-10 was identified as P. fluorescens. On the plate culture, strain P-72-10 produced pro-teinase, celluase, and siderophore, but not chitinase.%为探讨烟草根际生防细菌的生防机制,从重庆地区连作烟田健康炳株根际土壤中分离筛选到1株对烟草疫霉具有较强拮抗作用和对黑胫病具有良好防效的细菌菌株P-72-10.根据培养性状、形态特征、生理生化特性、基因组DNA的(G+C)mol%含量测定以及16S rDNA基因序列分析确定该菌株的分类地位.该菌株菌落乳白色,能产生水溶性荧光色素,革兰氏染色反应阴性,菌体秆状、大小(8.1 ~16.2)μm ×(1.8~4.8)μm,单端生鞭毛,不形成芽孢.The BIOLOG GN2结

  15. The C-terminal half of Phytophthora infestans RXLR effector AVR3a is sufficient to trigger R3a-mediated hypersensitivity and suppress INF1-induced cell death in Nicotiana benthamiana.

    Science.gov (United States)

    Bos, Jorunn I B; Kanneganti, Thirumala-Devi; Young, Carolyn; Cakir, Cahid; Huitema, Edgar; Win, Joe; Armstrong, Miles R; Birch, Paul R J; Kamoun, Sophien

    2006-10-01

    The RXLR cytoplasmic effector AVR3a of Phytophthora infestans confers avirulence on potato plants carrying the R3a gene. Two alleles of Avr3a encode secreted proteins that differ in only three amino acid residues, two of which are in the mature protein. Avirulent isolates carry the Avr3a allele, which encodes AVR3aKI (containing amino acids C19, K80 and I103), whereas virulent isolates express only the virulence allele avr3a, encoding AVR3aEM (S19, E80 and M103). Only the AVR3aKI protein is recognized inside the plant cytoplasm where it triggers R3a-mediated hypersensitivity. Similar to other oomycete avirulence proteins, AVR3aKI carries a signal peptide followed by a conserved motif centered on the consensus RXLR sequence that is functionally similar to a host cell-targeting signal of malaria parasites. The interaction between Avr3a and R3a can be reconstructed by their transient co-expression in Nicotiana benthamiana. We exploited the N. benthamiana experimental system to further characterize the Avr3a-R3a interaction. R3a activation by AVR3aKI is dependent on the ubiquitin ligase-associated protein SGT1 and heat-shock protein HSP90. The AVR3aKI and AVR3aEM proteins are equally stable in planta, suggesting that the difference in R3a-mediated death cannot be attributed to AVR3aEM protein instability. AVR3aKI is able to suppress cell death induced by the elicitin INF1 of P. infestans, suggesting a possible virulence function for this protein. Structure-function experiments indicated that the 75-amino acid C-terminal half of AVR3aKI, which excludes the RXLR region, is sufficient for avirulence and suppression functions, consistent with the view that the N-terminal region of AVR3aKI and other RXLR effectors is involved in secretion and targeting but is not required for effector activity. We also found that both polymorphic amino acids, K80 and I103, of mature AVR3a contribute to the effector functions.

  16. 烟草黑胫病菌拮抗放线菌的筛选%Screening of Antagonistic Actinomyce against Phytophthora nicotianae

    Institute of Scientific and Technical Information of China (English)

    李斌

    2012-01-01

    239 actinomyces strains were isolated from 29 soil samples, of which 48 isolates had antagonistic effects on Pkytophthora nicotianae with plate dual culture in proportion of 20. 1 %. Based on the characteristics of morphology and physiology-biochemistry, the antagonists were identified as Streptomyces(47 strains, 97.92 % )and Nocardia(1 strain). 4 actinomyces strains which showed superior antagonism in colony culture were selected to determine the inhibition of fermentation. The results showed that the average inhibition percentage was 59. 80 % , of which strain A27-12 was the highest(70.59 %), and the lowest inhibition percentage was A30-19(50.00 %), and both had significant difference. The results of greenhouse test indicated that the 4 actinomycetes had different control effects on curing tobacco blank shank. The strain A30-19 had the best effect, 78.79 % , which had no significant difference with 58 % Metalaxyl MnZn 800 times. Control effect of strain A36-15, A27-12 and A20-8 were 67.95 % , 57.41 % and 50.46 % , respectively.%采用稀释平板涂布法对29份根际土样进行分离,共获得239株放线菌,采用平板对峙培养法筛选得到48株对烟草黑胫病菌有拮抗作用的菌株,占筛选菌株的20.1%,根据形态和培养特征,48株拮抗放线菌被鉴定为链霉菌属(Streptomyces)和诺卡氏菌属(Nocardia),以链霉菌属为主,占拮抗菌的97.92%.对拮抗作用较好的4株放线菌进行了发酵液拮抗活性的测定,结果表明,4株放线菌平均抑制率为59.80%,其中菌株A27-12最高,为70.59%,菌株A30-19抑制率最低为50.00%,两者呈显著差异.4株菌株的温室盆栽防效测定结果表明,菌株A30-19效果最好,其平均防效为78.79%,与58%甲霜灵锰锌800倍液的防效无显著差异,另3个菌株A36-15、A27-12和A20-8对烟草黑胫病的平均防效分别为67.95%、57.41%和50.46%.

  17. Examination of some morphologically unusual cultures of Phytophthora species using a mitochondrial DNA miniprep technique and a standardised sporangium caducity assessment.

    Science.gov (United States)

    Hall, G S

    Using the mitochondrial DNA miniprep technique, the identity of sixteen morphologically unusual cultures allocated to Phytophthora nicotianae, Phytophthora mexicana or Phytophthora porri was determined by comparison with a library of mtDNA band patterns obtained from reference cultures. Seven cultures were identified as Phytophthora nicotianae (including those assigned to Phytophthora mexicana and Phytophthora porri), six as strains of Phytophthora palmivora with small, ovoid, weakly caducous sporangia, and one as Phytophthora citrophthora. Some cultures of P. nicotianae had a low percentage of caducous sporangia. Percentage sporangium caducity, but not sporangium L:B ratio, is considered a useful taxonomic criterion for separating species morphologically similar to Phytophthora nicotianae. One culture from tobacco in New Zealand had a highly unusual morphology and a unique DNA band pattern, but was not identifiable. One culture from Acacia mearnsii in South Africa had a unique DNA band pattern which was identical to that of an isolate from Annona squamosa from Australia previously identified as Phytophthora palmivora, the precise identity of which is still unclear. The identity of most isolates from diseased durian was found to be Phytophthora palmivora, confirming its role as the main pathogen, but P. nicotianae was also identified from this host.

  18. Toluca nog steeds resistent tegen phytophthora (interview met o.a. Geert Kessel)

    NARCIS (Netherlands)

    Engwerda, J.; Kessel, G.J.T.

    2009-01-01

    Het biologische aardappelras Toluca is nog steeds volledig resistent tegen phytophthora. Dat in een laboratorium drie isolaten van phytophthora de resistentie hebben omzeild, is een theoretisch gegeven, vindt commercieel directeur Jan van Hoogen van Agrico. Toluca is gekweekt door Agrico en in 2007

  19. Phytophthora viruses.

    Science.gov (United States)

    Cai, Guohong; Hillman, Bradley I

    2013-01-01

    Phytophthora sp. is a genus in the oomycetes, which are similar to filamentous fungi in morphology and habitat, but phylogenetically more closely related to brown algae and diatoms and fall in the kingdom Stramenopila. In the past few years, several viruses have been characterized in Phytophthora species, including four viruses from Phytophthora infestans, the late blight pathogen, and an endornavirus from an unnamed Phytophthora species from Douglas fir. Studies on Phytophthora viruses have revealed several interesting systems. Phytophthora infestans RNA virus 1 (PiRV-1) and PiRV-2 are likely the first members of two new virus families; studies on PiRV-3 support the establishment of a new virus genus that is not affiliated with established virus families; PiRV-4 is a member of Narnaviridae, most likely in the genus Narnavirus; and Phytophthora endornavirus 1 (PEV1) was the first nonplant endornavirus at the time of reporting. Viral capsids have not been found in any of the above-mentioned viruses. PiRV-1 demonstrated a unique genome organization that requires further examination, and PiRV-2 may have played a role in late blight resurgence in 1980s-1990s.

  20. Phytophthora lateralis.

    Science.gov (United States)

    E.M. Hansen

    2011-01-01

    Phytophthora lateralis was named by Tucker and Milbrath in 1942. There are no known synonyms. P. lateralis was classified in morphological group V by Stamps et al. (1990); the group includes homothallic species with paragynous antheridia and nonpapillate, proliferating sporangia.

  1. 烤烟品种NC297内生细菌中拮抗烟草黑胫病的生防菌筛选及种群组成分析%Isolation and phylogenetic analysis of the antagonistic endophytic bacteria against Phytophthora parasitica var.nicotianae from tobacco variety NC297

    Institute of Scientific and Technical Information of China (English)

    冯云利; 奚家勤; 马莉; 莫明和; 方敦煌; 夏振远; 雷丽萍; 杨发祥; 周峰

    2011-01-01

    从来自烤烟品种NC297的970株内生细菌中,以烟草黑胫病菌(Phytophthora parasitica var.nicoti-anae)为靶标,共筛选出165株拮抗菌,这些内生细菌对黑胫病菌的抑菌率在9.55%~55.96%之间.内生细菌的生物量在苗期、团棵期、开花期和成熟期中无显著差异,但拮抗菌数量呈上升趋势.对165株拮抗菌的16SrRNA基因序列进行RFLP分析共产生12种带型.根据RFLP带型选取41株进行16S rRNA基因序列测定和系统发育分析.结果表明这165株生防内生细菌归于3大类群%A total of 165 isolates with antagonistic effects against Phytophthora parasitica var.nicotianae were screened from 970 endophytic bacteria isolated from health leaves of tobacco variety NC297.Bioassay results in vivo showed that these antagonists exhibited different inhibitory activities to the pathogen which ranged from 9.55% to 55.96%.The biomass of endophytic bacteria varied not significantly during periods of seeding to maturity but the amount of antagonists increased in the growth process of tobacco.The 165 antagonists were characterized by RFLP analysis of the 16S rRNA sequence which were resulted 12 RFLP patterns.Thus,41 representative isolates,1—3 from each RFLP pattern,were selected for 16S rRNA sequencing.Phylogenetic analysis placed the 165 antagonists of P.parasitica var.nicotianae into three groups of Bacteria,namely Proteobacteria,Actinobacteria and Firmicutes.Members of the Bacillus genus in Firmicutes group were the dominant,in which 159 isolates represented by 6 RFLP patterns were associated with the species of Bacillus amyloliquefaciens subsp.plantarum,Bacillus methylotrophicu,Bacillus tequilensis,Bacillus aryabhattai,Bacillus cereus and Bacillus mycoide.And during all the 159 isolates two species,Bacillus amyloliquefaciens subsp.plantarum and Bacillus methylotrophicu,showed the highest isolated frequency.The remaining 6 isolates were respectively affiliated to the 6 species of Brevibacillus

  2. 抗菌肽和几丁质酶基因提高烟草对黑胫病菌和赤星病菌的抗性研究%Overexpression of antimicrobial peptide genes and a chitinase gene in transgenic tobacco enhances resistance to Phytophthora parasitica var. nicotianae and Alternaria alternata

    Institute of Scientific and Technical Information of China (English)

    罗小英; 曾雪嘉; 肖月华; 罗明; 杨星勇; 裴炎

    2005-01-01

    通过农杆菌介导法将加信号肽修饰的人工合成杂合抗菌肽CEMA基因(SPCEMA),苜蓿防御素基因(AFP),苦瓜几丁质酶基因(CHI)以及SPCEMA-CHI、AFP-CHI、AFP-SPCEMA双价基因导入本明烟(Nicotiana benthamiana),并对转基因烟草T0和T1代进行了抗病性检测,比较了不同转基因植株的抗病效果.研究结果表明,转基因烟草对黑胫病菌(Phytophthora parasitica var.nicotianae)、赤星病菌(Alternaria alternata)的抗性均强于非转基因烟草,病情指数差异达极显著水平,其中转AFP-CHI双价基因烟草具有较强的抗性,与单价转基因烟草的抗性差异达显著水平.但各单价转基因以及双价转基因烟草之间对上述病菌并未表现出显著的抗病性差异.结果表明植物源的抗菌肽基因与几丁质酶基因在抗植物真菌病害中具有协同增效作用.

  3. Phytophthora x pelgrandis, a new natural hybrid pathogenic to Pelargonium grandiflorum hort.

    Science.gov (United States)

    Nirenberg, Helgard I; Gerlach, Wolfram F; Gräfenhan, Tom

    2009-01-01

    A new Phytophthora hybrid of Ph. cactorum (Leb. & Cohn) Schroet. and Ph. nicotianaevan Breda de Haan pathogenic to cultivars of Pelargonium grandiflorum hort. is described as Phytophthora X pelgrandis and its morphological features are documented. Morphological, physiological (e.g., temperature requirements) and molecular data (DNA sequencing, random amplified polymorphic DNA-PCR) are presented for isolates of the Phytophthora hybrid. Pathogenicity was tested on cultivars of P. grandiflorum and Nicotiana tabacum. For comparison cultures of the parental species and additional Phytophthora taxa also were examined.

  4. Beleidsondersteunend Onderzoek Plantgezondheid BO-06 Resultaten 2009 : Phytophthora infestans (BO-06-008)

    NARCIS (Netherlands)

    Boonekamp, P.M.

    2010-01-01

    Een verzameling artikelen of rapporten over plantgezondheid. Het thema is Phytophthora infestans. Het plantgezondheidsonderzoek richt zich nog veel op het optimaliseren van bestaande methoden en technieken en korte termijnsuccesjes, vindt Piet Boonekamp. Voor een wezenlijke verduurzaming van plantge

  5. Phytophthora speelt verstoppertje bij NFT aardbei

    NARCIS (Netherlands)

    Evenhuis, B.; Verhoeven, J.T.W.

    2011-01-01

    Aardbeitelers worden 'blij' gemaakt met Phytophthora cactorum in hun gewas, terwijl ze daar niet op zitten te wachten. Onderzoekers worden teleurgesteld omdat infectie uitblijft terwijl ze er alles aan doen om aantasting te krijgen. Dat hindert ze bij het uitvinden wat het ontsmettingseffect is van

  6. Isolation and phylogenetic analysis of the antagonistic endophytic bacteria against Phytophthora parasitica var. nicotianae from tobacco variety NC297%灯盏花总黄酮和抗光氧化能力对外源茉莉酸的响应

    Institute of Scientific and Technical Information of China (English)

    姜维; 苏文华; 敖金成; 崔凤涛

    2011-01-01

    研究用不同浓度的外源茉莉酸处理灯盏花叶片,测定叶片黄酮和叶绿素含量及抗光氧化能力的变化.结果显示:茉莉酸处理后的3 d内黄酮含量变化不大,第6天则显著升高;0.5,1.0,1.5 mmol/L 3个浓度的茉莉酸处理组黄酮含量均高于对照,且1.5 mmol/L处理组黄酮含量明显比0.5和1.0 mmol/L处理组低.茉莉酸未对灯盏花光合作用造成损伤,但叶绿素b含量下降;类胡萝卜素含量都有所增加;叶绿素a在茉莉酸浓度为0.5 mmol/L时增加,而浓度为1.0和1.5 mmol/L时下降.0.5 mmol/L%A total of 165 isolates with antagonistic effects against Phytophthora parasitica var. nicotianae were screened from 970 endophytic bacteria isolated from health leaves of tobacco variety NC297. Bioassay results in vivo showed that these antagonists exhibited different inhibitory activities to the pathogen which ranged from 9.55% to 55.96%. The biomass of endophytic bacteria varied not significantly during periods of seeding to matu- rity but the amount of antagonists increased in the growth process of tobacco. The 165 antagonists were character- ized by RFLP analysis of the 16S rRNA sequence which were resulted 12 RFLP patterns. Thus,41 representative isolates ,1--3 from each RFLP pattern,were selected for 16S rRNA sequencing. Phylogenetic analysis placed the 165 antagonists of P. parasitica var. nicotianae into three groups of Bacteria, namely Proteobacteria,Actinobacte- ria and Firmicutes. Members of the Bacillus genus in Firmicutes group were the dominant, in which 159 isolates represented by 6 RFLP patterns were associated with the species of Bacillus amyloliquefaciens subsp, plantarum, Bacillus methylotrophicu ,Bacillus tequilensis ,Bacillus aryabhattai ,Bacillus cereus and Bacillus mycoide. And dur- ing all the 159 isolates two species, Bac.iUus amyloliquefaciens subsp, plantarum and Bacillus methylotrophicu, showed the highest isolated frequency. The remaining 6 isolates were respectively

  7. Isolation, Screening and Phylogenetic Analysis of Antagonistic Endophytic Bacteria Against Phytophthora Parasitica var.Nicotianae from Flue-cured Tobacco Variety K326%烤烟品种K326内生细菌分离、抗黑胫病菌株筛选及种群组成分析

    Institute of Scientific and Technical Information of China (English)

    奚家勤; 冯云利; 薛超群; 尹启生; 莫明和; 方敦煌; 王广山; 郭建华

    2013-01-01

    从烤烟品种K326的不同生长时期分离内生细菌1000株,以烟草黑胫病菌(Phytophthora parasitica var.nicotianae)为靶标,共筛选出168株拮抗菌,这些内生细菌对黑胫病菌的抑菌率在12.54%~50.14%之间.苗期和团棵期的内生菌含量较高,但在开花和成熟期时降低了一个数量级,而拮抗菌数量呈上升趋势.对168株拮抗菌的16SrRNA基因序列进行RFLP分析,共产生10种带型.根据RFLP带型选取39株进行16S rRNA基因序列测定和系统发育分析.结果表明,这168株生防内生细菌归于2大类群:Firmicutes和Actinobacteria.Firmicutes类群中的芽孢杆菌属(Bacillus)是优势属,共6种RFLP带型,150个菌株,包括Bacillus amyloliquefaciens subsp,plantarum,Bacillus tequilensis,Bacillus methylotrophicus,Bacillus cereus,Bacillus thuringiensis和Bacillus aryabhattai. Bacillus amyloliquefaciens subsp,plantarum和Bacillus methylotrophicus的出现频率最高,共126株,占该属总菌株数的78.75%.其余18个菌株分属于4个种:即Brevibacillus formosus,Brevibacillus parabrevis,Pseudomonas umsongensis和Pseudomonas aeruginosa.%A total of 168 isolates with antagonistic effects against Phytophthora parasitica var. nicotianae (P. parasitica var.) were screened from 1000 endophytic bacteria isolated from flue-cured tobacco variety K326 at different growing stages, and bioassay results indicated that the inhibitory activities of these antagonists ranged from 12.54% to 50.14%. The biomass of endophytic bacteria was higher during the stages of seedling and rosette, which reduced by one order of magnitude during the stages of flowering and maturity; however, the number of antagonists kept an increasing trend. The RFLP analysis of 16S rRNA sequence on the 168 antagonists produced 10 RFLP patterns. Based on their RFLP patterns, 39 isolates were selected for 16S rRNA sequencing and phylogenetic analysis. The results showed that the 168 antagonists belonged to two groups of bacteria

  8. Susceptibility of common alder (Alnus glutinosa) seeds and seedlings to Phytophthora alni and other Phytophthora species

    Energy Technology Data Exchange (ETDEWEB)

    Haque, M. M.; Diez, J. J.

    2012-11-01

    Phytophthora alni is a highly destructive host specific pathogen to alders (Alnus spp.) spreading all over Europe. Recently this pathogen has been reported to cause diseases in common alder (Alnus glutinosa) in Spain. Seeds and seedlings of A. glutinosa were tested in vitro for their susceptibility to alder Phytophthora and other Phytophthora species. Isolates of P. alni ssp. alni, P. cinnamomi, P. citrophthora, P. nicotianae and P. palmivora were used in the experiments. Seeds and seedlings were inoculated with a zoospore suspension and uniform mycelial blocks of agar of the Phytophthora species. Susceptibility was calculated in terms of pathogen virulence on seed germination and seedling mortality 42 and 67 days after inoculation respectively. Seed germination and seedling mortality rates varied differently among the isolates used. Results implied that common alder and its seeds and seedlings are at risk to be infected by P. alni. In addition, other Phytophthora species are able to infect this kind of material showing their relative host non-specificity. This is one important finding concerning alder regeneration in infected areas, and the possibility of disease spread on this plant material. (Author) 42 refs.

  9. Morphological and Molecular Description of Phytophthora insolita Isolated from Citrus Orchard in India

    Directory of Open Access Journals (Sweden)

    Swapnil Bawage

    2013-01-01

    Full Text Available Citrus, an important cash crop in India, is adversely affected by Phytophthora nicotianae, P. palmivora, and P. citrophthora. Phytophthora insolita is known to be associated with citrus and reported for the first time in India. It is a rare and poorly characterized Phytophthora species, as its natural host and pathogenic impact are unclear. Previously, it was reported only in Taiwan and China; so to confirm our suspected isolate is P. insolita, regions of internal transcribed spacer, elongation factor, beta-tubulin, and cytochrome oxidase genes were sequenced. This study provides description of the lone Indian P. insolita isolate with respect to molecular identity, morphology, mating behaviour, and pathogenicity.

  10. 烟草黑胫病拮抗内生细菌的分离、鉴定及防效测定%Isolation, identification and control efficacy determination of an endophytic strain against Phytophthora parasitica var.nicotianae

    Institute of Scientific and Technical Information of China (English)

    陈泽斌; 夏振远; 雷丽萍; 陈海如

    2011-01-01

    269 endophytic bacteria were isolated from healthy tobacco plant with conventional isolation method. Seven strains that obviously antagonized against growth of P. Parasitica var. Nicotianae were screened, all with above 6mm width of inhibitory zone. Antagonistic activity test showed that there existed some antagonistic substances in the culture filtrates for strain 05-4004 and 05-2501. Pathogenic test showed that strain 701-1 exhibited obvious or potential pathoge-nicity to tobacco after inoculation. Other 6 strains were tested with greenhouse experiment and results showed that strain 05-4004 and 05-2002 were the most effective strains against P. Parasitica var nicotianae with control efficacy of 46. 6% and 45. 2% . Germination rates of tobacco seeds in NB culture and untreated seeds were 84. 3% and 82. 7% , respectively, while seeds soaked in strain 05-2002 and 05-4004 culture were improved to 93. 5% and 93.1%. Plant height, leaf length, leaf width and number of leaves were effectively increased when roots were irrigated with strain 05-2002 and 05-4004 culture. Phylogentic analysis based on 16S rDNA suggested that 05-4004 shared 99% homologies with Bacillus pumilus (EU366363) and Bacillus safensis (AY030327). These sequences constituted a branch in phylogenetic tree.%采用常规分离方法从健康烟株的根、茎、叶中分离得到内生细菌269株,从中筛选出7株对烟草黑胫病病原菌具有明显拮抗作用的菌株,它们的抑菌半径达到6 mm以上.菌株05-4004、05-2501培养液滤液中存在具有明显抑菌作用的活性成分.致病性试验中,发现菌株701-1在人工接种条件下有致病能力或潜在致病性,选择余下6株拮抗细菌进行了温室盆栽试验,以05-4004、05-2002两株烟草内生细菌对烟草黑胫病的防效最好,分别为46.6%、45.2%.促生试验中,NB培养液和清水对照的种子发芽率分别为84.3%、82.7%,而经过05-2002和05-4004除菌滤液浸

  11. Dynamic distribution of endophytic bacteria and their antagonism to phytophthora nicotianae in tobacco plant in Guangxi%广西烟草内生细菌的动态分布及其对烟草疫霉的拮抗作用

    Institute of Scientific and Technical Information of China (English)

    陈永珍; 杨义; 卢燕回; 陈振东; 黎起秦; 袁高庆; 林纬

    2012-01-01

    470 bacterial strains were isolated from 9 tobacco cultivars collected from Guangxi province. Based on conventional methods and 16s DNA sequence analysis, these strains were identified as Enterobacter, Serratia, Bacillus, Agrobacterium, Stenotrophomna and Pseudomonas, of which Agrobacterium and Enterobacter were dominant genus. The genera and population of endophytic bacteria in tobacco plants varied with cultivating regions, cultivars, tissues and growth stages. The endophytic bacteria were most frequently isolated in roots, followed by stems and leaves. Total a-mount of endophytic bacteria increased gradually from seedling stage to flourishing stage, and then decreased dramatically. 56 of the 470 isolates exhibited antagonistic activity against Phytophthora nicotianae, and Bacillus subtilis strain Y10 was the strongest antagonist with an inhibitory rate of 91. 48%. The control efficacy of strain Y10 on tobacco black shank was 68. 72% in greenhouse.%从广西百色市的9个烟草品种中分离出470株内生细菌菌株,经常规细菌鉴定方法和16S rDNA序列分析,获得的菌株分别属于肠杆菌属(Enterobacter)、沙雷氏菌属(Serratia)、芽孢杆菌属(Bacillus)、土壤杆菌属(Agrobacterium)、寡养单胞菌属(Stenotrophomnas)和假单胞菌属(Pseudomonas),其中土壤杆菌属和肠杆菌属为烟草内生细菌中的优势种群.烟草内生细菌的类群和数量随烟草种植地点、品种、器官和生育期的不同而不同.烟草内生细菌在根部数量最多,其次是茎和叶.内生细菌的总量从缓苗期到旺长期增加,之后显著下降.从470株烟草内生细菌菌株中筛选出对烟草疫霉有拮抗作用的菌株56株,其中芽孢杆菌菌株Y10的抑制效果最好,抑制率达91.48%,室内盆栽防治效果为68.72%.

  12. 广州地区茄疫病的发生及疫霉种鉴定%On the Occurrence and the Identification of Eggplant's Phytophthora Disease in Guangzhou Region

    Institute of Scientific and Technical Information of China (English)

    成家壮; 韦小燕

    2002-01-01

    1987~1999年,从广州地区茄的果实、茎、叶及根上分离得到疫霉菌,根据形态特征、培养性状及生理特性等方面研究结果,鉴定出4个种,其中以辣椒疫霉Phytophthora capsici Leon较为普遍,烟草疫霉P.nicotianae Van Breda de Haan次之, 掘氏疫霉P.drechsleri Tucker较少出现,致病疫霉P.infestans (Montagne) de Bary 仅见于春季;此外,种群分布与前作及不同季节有关.

  13. Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6.

    Science.gov (United States)

    Hansen, Everett M; Reeser, Paul W; Sutton, Wendy

    2012-01-01

    Phytophthora borealis and Phytophthora riparia, identified in recent Phytophthora surveys of forest streams in Oregon, California and Alaska, are described as new species in Phytophthora ITS Clade 6. They are similar in growth form and morphology to P. gonapodyides and are predominantly sterile. They present unique DNA sequences, however, and differ in temperature/growth relations and geographic distribution.

  14. Geschiktheid biologische aardappelrassen voor biofrites en biochips : verkenning naar eisen en de mogelijkheden van de huidige biologische aardappelrassen voor biofrites en biochips

    NARCIS (Netherlands)

    Wijk, van C.A.P.; Bus, C.B.

    2011-01-01

    Uit bakproeven met biologische aardappelrassen blijkt dat een aantal rassen met een hoog niveau van Phytophthora-resistentie, perspectief biedt voor goede frites- en chipbereiding. Hoewel de bakkwaliteit van deze rassen standaard minder optimaal was dan van het ras Phytophthora-gevoelige hoofdras Ag

  15. Geschiktheid biologische aardappelrassen voor biofrites en biochips : verkenning naar eisen en de mogelijkheden van de huidige biologische aardappelrassen voor biofrites en biochips

    NARCIS (Netherlands)

    Wijk, van C.A.P.; Bus, C.B.

    2011-01-01

    Uit bakproeven met biologische aardappelrassen blijkt dat een aantal rassen met een hoog niveau van Phytophthora-resistentie, perspectief biedt voor goede frites- en chipbereiding. Hoewel de bakkwaliteit van deze rassen standaard minder optimaal was dan van het ras Phytophthora-gevoelige hoofdras Ag

  16. Phytophthora beyond agriculture.

    Science.gov (United States)

    Hansen, Everett M; Reeser, Paul W; Sutton, Wendy

    2012-01-01

    Little is known about indigenous Phytophthora species in natural ecosystems. Increasing evidence, however, suggests that a diverse, trophically complex Phytophthora community is important in many forests. The number of described species has steadily increased, with a dramatic spike in recent years as new species have been split from old and new species have been discovered through exploration of new habitats. Forest soil, streams, and the upper canopies of trees are now being explored for Phytophthora diversity, and a new appreciation for the ecological amplitude of the genus is emerging. Ten to twenty species are regularly identified in temperate forest surveys. Half or more of this Phytophthora diversity comes from species described since 2000. Taxa in internal transcribed spacer (ITS) Clade 6 are especially numerous in forest streams and may be saprophytic in this habitat. Three ecological assemblages of forest Phytophthora species are hypothesized: aquatic opportunists, foliar pathogens, and soilborne fine-root and canker pathogens. Aggressive invasive species are associated with all three groups.

  17. THE INFLUENCE OF NATURAL ESSENTIAL OILS ON THE GROWTH OF PHYTOPHTHORA SPP. ISOLATED FROM PELARGONIUM CUTTINGS

    Directory of Open Access Journals (Sweden)

    Marcelina Machura

    2017-10-01

    Full Text Available Ornamental plants play an important role in human life. Plants positively influence the psyche and improve the well-being of people around them. They produce oxygen, provide a barrier to dust and noise, lower the temperature and increase air humidity, thereby positively impacting the microclimate. The unmatched appeal of pelargonium, ease of cultivation and care, abundance of flowering from spring to late autumn and its decorative qualities make it a universal application. The aim of the study was to isolate the microorganisms that inhabit the cuttings of pelargonium, identify fungal isolates, investigate the pathogenicity of selected isolates and evaluate the influence of certain essential oils (Carum carvi L. essential oils, Citrus limon L. essential oils, Citrus reticulatae aetheroleum essential oils, essential oil of tea tree in in vitro circumstances on the linear growth of the mycelium: Phytophthora cryptogea, Phytophthora nicotianae var. nicotianae. Previcur Energy 840 SL was used as a standard chemical protection. The most numerous isolated fungi were: Phytophthora, Botrytis, Cylindrocladium, Alternaria and Cylindrocarpon. The highest efficiency in relation to Phytophthora cryptogea characterized the Citrus limon L. essential oils (concentration 0.1% and 1% and Carum carvi L. essential oil (concentration 1%.

  18. Comparison of Isolating and Culturing Phytophthora infestans and P.nicotianae Among Several Selective Media%几种选择性培养基对致病疫霉和烟草疫霉分离及培养比较研究

    Institute of Scientific and Technical Information of China (English)

    朱桂宁; 黄福新

    2002-01-01

    @@ 致病疫霉(Phytophthora infestans)是疫霉属真菌中一个重要的种,引起马铃薯、番茄的晚疫病,造成马铃薯、番茄生产的严重损失.近年来,晚疫病对作物的为害日益严重,引起了广大植病工作者的重视.

  19. Fighting phytophthora in blueberries

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  20. The genus Phytophthora anno 2012.

    Science.gov (United States)

    Kroon, Laurens P N M; Brouwer, Henk; de Cock, Arthur W A M; Govers, Francine

    2012-04-01

    Plant diseases caused by Phytophthora species will remain an ever increasing threat to agriculture and natural ecosystems. Phytophthora literally means plant destroyer, a name coined in the 19th century by Anton de Bary when he investigated the potato disease that set the stage for the Great Irish Famine. Phytophthora infestans, the causal agent of potato late blight, was the first species in a genus that at present has over 100 recognized members. In the last decade, the number of recognized Phytophthora species has nearly doubled and new species are added almost on a monthly basis. Here we present an overview of the 10 clades that are currently distinguished within the genus Phytophthora with special emphasis on new species that have been described since 1996 when Erwin and Ribeiro published the valuable monograph 'Phytophthora diseases worldwide' (35).

  1. Universality of the Phytophthora mating hormones and diversity of their production profile.

    Science.gov (United States)

    Tomura, Tomohiko; Molli, Shylaja D; Murata, Ryo; Ojika, Makoto

    2017-07-10

    Sexual reproduction of the plant pest Phytophthora is regulated by two mating hormones α1 and α2, which are acyclic oxygenated diterpenes first isolated from P. nicotianae A1 and A2 mating types, respectively. A previous report suggested the universality of these factors within this genus. To confirm this concept, we investigated 80 strains (19 species) of Phytophthora and a related genus, not only for the responsiveness to mating hormones but also for their productivity. The results indicated that among the 55 heterothallic strains, 24 (44%) responded to a mating hormone and 40 (73%) produced one or both hormones. These findings demonstrate the interspecies universality of mating hormones within the genus Phytophthora. Hormone productivity was found to be highly diverse and dependent on the strains used. Although the A2 mating type has been regarded as the α2 producer, 19 (59%) of the 32 A2-type strains produced both the hormones and two A2-type strains exclusively produced α1 in high yields. These results indicate that hormone biosynthesis in Phytophthora is universal but highly diverse and complex, and varies with culture conditions, providing us valuable information for future studies on the mechanism of mating hormone biosynthesis of Phytophthora.

  2. Draft genome sequences of Phytophthora kernoviae and Phytophthora ramorum lineage EU2 from Scotland

    OpenAIRE

    Christine Sambles; Alexandra Schlenzig; Paul O'Neill; Murray Grant; Studholme, David J.

    2015-01-01

    Newly discovered Phytophthora species include invasive pathogens that threaten trees and shrubs. We present draft genome assemblies for three isolates of Phytophthora kernoviae and one isolate of the EU2 lineage of Phytophthora ramorum, collected from outbreak sites in Scotland.

  3. Identification of Phytophthora Species on Phytophthora Blight of Vanilla%香草兰疫病疫霉菌种的鉴定

    Institute of Scientific and Technical Information of China (English)

    曾会才; 张开明; 李锐; 贺春萍

    2000-01-01

    从云南西双版纳的景洪、勐腊两地的热带作物园香草兰疫病果荚、茎节、叶片上分离到10个疫霉分离菌,根据孢子囊、厚垣孢子、藏卵器、雄器形态、菌落形态及主要生长温度,鉴定为烟草疫霉(寄生疫霉)Phytophthora nicotianae(P.parasitice)10个分离菌株均属于A1交配型.

  4. Phytophthora effector targets a novel component of small RNA pathway in plants to promote infection.

    Science.gov (United States)

    Qiao, Yongli; Shi, Jinxia; Zhai, Yi; Hou, Yingnan; Ma, Wenbo

    2015-05-05

    A broad range of parasites rely on the functions of effector proteins to subvert host immune response and facilitate disease development. The notorious Phytophthora pathogens evolved effectors with RNA silencing suppression activity to promote infection in plant hosts. Here we report that the Phytophthora Suppressor of RNA Silencing 1 (PSR1) can bind to an evolutionarily conserved nuclear protein containing the aspartate-glutamate-alanine-histidine-box RNA helicase domain in plants. This protein, designated PSR1-Interacting Protein 1 (PINP1), regulates the accumulation of both microRNAs and endogenous small interfering RNAs in Arabidopsis. A null mutation of PINP1 causes embryonic lethality, and silencing of PINP1 leads to developmental defects and hypersusceptibility to Phytophthora infection. These phenotypes are reminiscent of transgenic plants expressing PSR1, supporting PINP1 as a direct virulence target of PSR1. We further demonstrate that the localization of the Dicer-like 1 protein complex is impaired in the nucleus of PINP1-silenced or PSR1-expressing cells, indicating that PINP1 may facilitate small RNA processing by affecting the assembly of dicing complexes. A similar function of PINP1 homologous genes in development and immunity was also observed in Nicotiana benthamiana. These findings highlight PINP1 as a previously unidentified component of RNA silencing that regulates distinct classes of small RNAs in plants. Importantly, Phytophthora has evolved effectors to target PINP1 in order to promote infection.

  5. The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA.

    Science.gov (United States)

    Sims, Laura Lee; Sutton, Wendy; Reeser, Paul; Hansen, Everett M

    2015-01-01

    Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described "P. taxon Pgchlamydo", and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in downstream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described "P. taxon Oaksoil", which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides.

  6. Phytophthora sojae: Diversity among and within Populations

    Science.gov (United States)

    Soybean production is increasing around the world and, to no surprise, so are the reports of soybean diseases caused by Phytophthora sojae, including Phytophthora seed, root, and stem rot. Phytophthora sojae is a diploid oomycete, which is homothallic and is limited to primarily one host: the soybe...

  7. 菠萝心腐病原疫霉种的鉴定%Identification of Pineapple Phytophthora Pathogen of Pineapple Leaf Heart-rot in Guangzhou Region

    Institute of Scientific and Technical Information of China (English)

    成家壮; 韦小燕

    2003-01-01

    1997~2000年,从广州及其周边地区的菠萝心腐植株上分离得到疫霉菌8株,鉴定出3个种,即柑桔褐腐疫霉(Phytophthora citrophthora)1株,烟草疫霉(P.nicotianae)5株和棕榈疫霉(P.palmivora)2株.

  8. Recombinant protein expression in Nicotiana.

    Science.gov (United States)

    Matoba, Nobuyuki; Davis, Keith R; Palmer, Kenneth E

    2011-01-01

    Recombinant protein pharmaceuticals are now widely used in treatment of chronic diseases, and several recombinant protein subunit vaccines are approved for human and veterinary use. With growing demand for complex protein pharmaceuticals, such as monoclonal antibodies, manufacturing capacity is becoming limited. There is increasing need for safe, scalable, and economical alternatives to mammalian cell culture-based manufacturing systems, which require substantial capital investment for new manufacturing facilities. Since a seminal paper reporting immunoglobulin expression in transgenic plants was published in 1989, there have been many technological advances in plant expression systems to the present time where production of proteins in leaf tissues of nonfood crops such as Nicotiana species is considered a viable alternative. In particular, transient expression systems derived from recombinant plant viral vectors offer opportunities for rapid expression screening, construct optimization, and expression scale-up. Extraction of recombinant proteins from Nicotiana leaf tissues can be achieved by collection of secreted protein fractions, or from a total protein extract after grinding the leaves with buffer. After separation from solids, the major purification challenge is contamination with elements of the photosynthetic complex, which can be solved by application of a variety of facile and proven strategies. In conclusion, the technologies required for safe, efficient, scalable manufacture of recombinant proteins in Nicotiana leaf tissues have matured to the point where several products have already been tested in phase I clinical trials and will soon be followed by a rich pipeline of recombinant vaccines, microbicides, and therapeutic proteins.

  9. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control.

    Science.gov (United States)

    Blaya, Josefa; Marhuenda, Frutos C; Pascual, Jose A; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

  10. Draft genome sequences of Phytophthora kernoviae and Phytophthora ramorum lineage EU2 from Scotland

    Directory of Open Access Journals (Sweden)

    Christine Sambles

    2015-12-01

    Full Text Available Newly discovered Phytophthora species include invasive pathogens that threaten trees and shrubs. We present draft genome assemblies for three isolates of Phytophthora kernoviae and one isolate of the EU2 lineage of Phytophthora ramorum, collected from outbreak sites in Scotland.

  11. Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity

    Science.gov (United States)

    Stam, Remco; Jupe, Julietta; Howden, Andrew J. M.; Morris, Jenny A.; Boevink, Petra C.; Hedley, Pete E.; Huitema, Edgar

    2013-01-01

    Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN) gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions. PMID:23536880

  12. Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity.

    Directory of Open Access Journals (Sweden)

    Remco Stam

    Full Text Available Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions.

  13. ‘COROJO 2006’: NUEVA VARIEDAD CUBANA DE TABACO NEGRO (Nicotiana tabacum L.

    Directory of Open Access Journals (Sweden)

    Vivaldo García Morejón

    2013-01-01

    Full Text Available En la Estación Experimental del Tabaco, de San Juan y Martínez, Pinar del Río durante la campaña tabacalera 2001-2002, se realizó un cruzamiento sexual con el objetivo de obtener una variedad de tabaco negro con mayor rendimiento que la comercial ‘Criollo 98’, resistente al moho azul ( Peronospora hyocyami de Bary, a la pata prieta ( Phytophthora parasitica Dast. var . Nicotianae Breda de Haan, al virus del mosaico del tabaco (VMT y a la necrosis ambiental. Después de cinco generaciones de autofecundación y selección por el método genealógico se obtuvieron siete variedades resistentes. El cruce originó la nueva variedad `Corojo 2006 ́ que superó a la `Criollo 98 ́.

  14. Arabidopsis Lectin Receptor Kinases LecRK-IX.1 and LecRK-IX.2 Are Functional Analogs in Regulating Phytophthora Resistance and Plant Cell Death.

    Science.gov (United States)

    Wang, Yan; Cordewener, Jan H G; America, Antoine H P; Shan, Weixing; Bouwmeester, Klaas; Govers, Francine

    2015-09-01

    L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showing additive susceptibility. Overexpression of LecRK-IX.1 or LecRK-IX.2 in Arabidopsis and transient expression in Nicotiana benthamiana increased Phytophthora resistance but also induced cell death. Phytophthora resistance required both the lectin domain and kinase activity, but for cell death, the lectin domain was not needed. Silencing of the two closely related mitogen-activated protein kinase genes NbSIPK and NbNTF4 in N. benthamiana completely abolished LecRK-IX.1-induced cell death but not Phytophthora resistance. Liquid chromatography-mass spectrometry analysis of protein complexes coimmunoprecipitated in planta with LecRK-IX.1 or LecRK-IX.2 as bait, resulted in the identification of the N. benthamiana ABC transporter NbPDR1 as a potential interactor of both LecRK. The closest homolog of NbPDR1 in Arabidopsis is ABCG40, and coimmunoprecipitation experiments showed that ABCG40 associates with LecRK-IX.1 and LecRK-IX.2 in planta. Similar to the LecRK mutants, ABCG40 mutants showed compromised Phytophthora resistance. This study shows that LecRK-IX.1 and LecRK-IX.2 are Phytophthora resistance components that function independent of each other and independent of the cell-death phenotype. They both interact with the same ABC transporter, suggesting that they exploit similar signal transduction pathways.

  15. Evaluation of natural plant extracts, antagonists and fungicides in controlling root rot, collar rot, fruit (brown rot and gummosis of citrus caused by Phytophthora spp. in vitro

    Directory of Open Access Journals (Sweden)

    G.P. Jagtap

    2012-07-01

    Full Text Available The results revealed that all the six bioagents tested in vitro applying dual culture technique against Phytophthora nicotianae, Phytophthora citrophthora and Phytophthora palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, bioagent, Trichoderma harzianum recorded minimum mean colony diameter (7.73 cm2 and highest inhibition (87.85% of mycelial growth of P. nicotianae over untreated control followed by the bioagent T. viride, T. koningii which recorded mean colony diameter of 9.95 cm2, 14.15 cm2 and mean mycelial inhibition of 84.36 %, 77.76%, respectively. Evaluation of different botanicals by Poisoned Food Technique showed that all plant extracts tested in vitro were found significantly effective in reducing the percentage mycelial growth of P. nicotianae, P. citrophthora and P. palmivora over untreated control. However, plant extract (@ 5, 10 and 15% of Garlic, recorded lowest mean colony diameter (47.45 mm and highest mean mycelial growth inhibition (47.26% followed by Neem, Onion which recorded the mycelial growth of 55.20 mm, 60.85 mm, and the mean mycelial growth inhibition of 38.65%, 32.38%, respectively. Results revealed that all the nine fungicides tested in vitro applying Poisoned Food Technique against P. nicotianae, P. citrophthora and P. palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, fungicide, Cymoxynil 8% + Mancozeb 64% (Curzate M-8 recorded minimum mean colony diameter (16.12 mm and maximum mean inhibition (82.09% of mycelial growth of the test pathogen over untreated control (mean colony diameter 90.00 mm and mean inhibition 0.00 followed by the fungicide Metalaxyl-M 4% + Mancozeb 64% (Ridomil Gold, Metyram (Polyram, which recorded mean colony diameter of 20.16 mm, 24.16 mm and mean mycelial inhibition of 77.59%, 73.14%, respectively.

  16. Phytophthora genome sequences uncover evolutionary origins and mechanisms of pathogenesis

    NARCIS (Netherlands)

    Tyler, B.M.; Tripathy, S.; Zhang, X.; Dehal, P.; Jiang, R.H.Y.; Aerts, A.; Arredondo, F.D.; Baxter, L.; Bensasson, D.; Beynon, J.L.; Chapman, J.; Damasceno, C.M.B.; Dorrance, A.E.; Dou, D.; Dickerman, A.W.; Dubchak, I.L.; Garbelotto, M.; Gijzen, M.; Gordon, S.G.; Govers, F.; Grunwald, N.J.; Huang, W.; Ivors, K.L.; Jones, R.W.; Kamoun, S.; Krampis, K.; Lamour, K.H.; Lee, M.K.; McDonald, W.H.; Medina, M.; Meijer, H.J.G.; Nordberg, E.K.; Maclean, D.J.; Ospina-Giraldo, M.D.; Morris, P.F.; Phuntumart, V.; Putnam, N.H.; Rash, S.; Rose, J.K.C.; Sakihama, Y.; Salamov, A.A.; Savidor, A.; Scheuring, C.F.; Smith, B.M.; Sobral, B.W.S.; Terry, A.; Torto-Alalibo, T.A.; Win, J.; Xu, Z.; Zhang, H.; Grigoriev, I.V.; Rokhsar, D.S.; Boore, J.L.

    2006-01-01

    Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oömycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora

  17. Nicotiana glauca poisoning in ostriches (Struthio camelus)

    CSIR Research Space (South Africa)

    Botha, CJ

    2011-01-01

    Full Text Available Putative Nicotiana glauca (wild tobacco) poisoning was diagnosed in a flock of ostriches near Oudtshoorn, South Africa. Post mortem examinations (n = 7) were performed on ostriches (Struthio camelus) that had died. Suspicious leaf remnants (weighing...

  18. Screening Phytophthora rubi for fungicide resistance

    Science.gov (United States)

    Preliminary results from the survey for fungicide resistance in Phytophthora were reported at the 2016 Washington Small Fruit Conference. Phytophthora was isolated from diseased plants in 28 red raspberry fields and tested against mefenoxam, the active ingredient of Ridomil. Most isolates were ident...

  19. Targeted gene mutation in Phytophthora spp.

    NARCIS (Netherlands)

    Lamour, K.H.; Finley, L.; Hurtado-Gonzales, O.; Gobena, D.; Tierney, M.; Meijer, H.J.G.

    2006-01-01

    The genus Phytophthora belongs to the oomycetes and is composed of plant pathogens. Currently, there are no strategies to mutate specific genes for members of this genus. Whole genome sequences are available or being prepared for Phytophthora sojae, P. ramorum, P. infestans, and P. capsici and the d

  20. Praktijkproef covergisting van varkensmest

    NARCIS (Netherlands)

    Timmerman, M.; Claessen, P.; André, G.

    2007-01-01

    In dit rapport wordt verslag gedaan van een praktijkproef uitgevoerd naar covergisting van nevenproducten uit de levensmiddelenindustrie met varkensmest. De doelstelling van de uitgevoerde praktijkproef was het bepalen van de biogasopbrengst van vijf coproducten, de samenstelling van het biogas, de

  1. Phytophthora elicitor PB90 induced apoptosis in suspension cultures of tobacco

    Institute of Scientific and Technical Information of China (English)

    JI Rui; ZHANG Zhengguang; WANG Yuanchao; ZHENG Xiaobo

    2005-01-01

    The protein elicitor PB90 secreted by Phytophthora boehmeriae is an efficient elicitor inducing the hypersensitive response and systemic acquired resistance in tobacco plants. Here, we observed cell death in suspension-cultured cells of Nicotiana tabacum BY-2 with PB90 treatment using Trypan blue staining method. And this cell death could be suppressed by cycloheximide, an inhibitor of proteins synthesis, which implies that PB90-induced cell death was an active cell death process requiring new protein synthesis. DAPI staining revealed that PB90 induce rapid chromatin condensation, margination, apoptotic bodies' formation and DNA laddering, further TUNEL assay also observed the specific breakage of 3′-OH ends. All of the above common morphological characteristics indicated that PB90 induced apoptosis in suspension cultures of tobacco, suggesting that hypersensitive response induced by PB90 is an apoptotic process.

  2. The Arabidopsis lectin receptor kinase LecRK-I.9 enhances resistance to Phytophthora infestans in Solanaceous plants.

    Science.gov (United States)

    Bouwmeester, Klaas; Han, Miao; Blanco-Portales, Rosario; Song, Wei; Weide, Rob; Guo, Li-Yun; van der Vossen, Edwin A G; Govers, Francine

    2014-01-01

    Late blight caused by the plant pathogenic oomycete Phytophthora infestans is known as one of the most destructive potato diseases. Plant breeders tend to employ NB-LRR-based resistance for introducing genetically controlled late blight resistance in their breeding lines. However, P. infestans is able to rapidly escape this type of resistance, and hence, NB-LRR-based resistance in potato cultivars is often not durable. Previously, we identified a novel type of Phytophthora resistance in Arabidopsis. This resistance is mediated by the cell surface receptor LecRK-I.9, which belongs to the family of L-type lectin receptor kinases. In this study, we report that expression of the Arabidopsis LecRK-I.9 gene in potato and Nicotiana benthamiana results in significantly enhanced late blight resistance. Transcriptional profiling showed strong reduction in salicylic acid (SA)-mediated defence gene expression in LecRK-I.9 transgenic potato lines (TPLs). In contrast, transcripts of two protease inhibitor genes accumulated to extreme high levels, suggesting that LecRK-I.9-mediated late blight resistance is relying on a defence response that includes activation of protease inhibitors. These results demonstrate that the functionality of LecRK-I.9 in Phytophthora resistance is maintained after interfamily transfer to potato and N. benthamiana and suggest that this novel type of LecRK-based resistance can be exploited in breeding strategies to improve durable late blight resistance in Solanaceous crops.

  3. Pathogenic diversity of Phytophthora sojae and breeding strategies to develop Phytophthora-resistant soybeans

    Science.gov (United States)

    Phytophthora stem and root rot disease, caused by Phytophthora sojae, is one of the most destructive diseases of soybean (Glycine max (L.) Merr.), and has been increasing in several soybean-producing areas around the world. This disease induces serious limitations on soybean production, with yield l...

  4. Mitochondrial genomics in the Genus Phytophthora with a focus on Phytophthora ramorum

    Science.gov (United States)

    Frank N. Martin; Paul Richardson

    2008-01-01

    The mitochondrial genomes of Phytophthora infestans, P. ramorum and P. sojae have been sequenced and comparative genomics has provided an opportunity to examine the processes involved with genome evolution in the genus Phytophthora. This approach can also be useful in assessing intraspecific...

  5. Phytophthora Database: A forensic database supporting the identification and monitoring of Phytophthora

    Science.gov (United States)

    Due to their high virulence and ability to spread rapidly, Phytophthora species represent a serious threat to agricultural production and ecological systems. Many novel Phytophthora species have been reported in recent years, indicative of our limited understanding of the ecology and diversity of Ph...

  6. Phytophthora rotråte i juletrefelt

    DEFF Research Database (Denmark)

    Talgø, Venche; Thomsen, Iben Margrete

    2015-01-01

    Phytophthora rotråte forårsaket av ulike arter av Phytophthora er et stort problem i juletreproduksjonen iUSA. I Norge er det også rapportert om flere tilfeller av skade på grunn av Phytophthora både i juletrær og klippegrønt, men så langt ikke i Danmark. I begge landene er flere arter av...... Phytophthora funnet på treaktige vekster i grøntanlegg. Vi har også sett en urovekkende spredning av Phytophthora til løvtrær i bynære skoger, vassdrag og naturområder det siste tiåret, spesielt i Norge. Både i Norge og Danmark har vi undersøkt vann i eller like ved juletreplantinger og funnet flere...... Phytophthora-arter, så dette er en skadegjører juletredyrkere må være på vakt overfor...

  7. Intracellular and extracellular phosphatidylinositol 3-phosphate produced by Phytophthora species is important for infection.

    Science.gov (United States)

    Lu, Shan; Chen, Linlin; Tao, Kai; Sun, Nannan; Wu, Yuren; Lu, Xiaoxue; Wang, Yuanchao; Dou, Daolong

    2013-09-01

    RxLR effectors produced by Phytophthora pathogens have been proposed to bind to phosphatidylinositol 3-phosphate (PtdIns(3)P) to mediate their translocation into host cells and/or to increase their stability in planta. Since the levels of PtdIns(3)P in plants are low, we examined whether Phytophthora species may produce PtdIns(3)P to promote infection. We observed that PtdIns(3)P-specific GFP biosensors could bind to P. parasitica and P. sojae hyphae during infection of Nicotiana benthamiana leaves transiently secreting the biosensors, suggesting that the hyphae exposed PtdIns(3)P on their plasma membrane and/or secreted PtdIns(3)P. Silencing of the phosphatidylinositol 3-kinases (PI3K) genes, treatment with LY294002, or expression of PtdIns(3)P-binding proteins by P. sojae reduced the virulence of the pathogen on soybean, indicating that pathogen-synthesized PtdIns(3)P was required for full virulence. Secretion of PtdIns(3)P-binding proteins or of a PI3P-5-kinase by N. benthamiana leaves significantly increased the level of resistance to infection by P. parasitica and P. capsici. Together, our results support the hypothesis that Phytophthora species produce external PtdIns(3)P to aid in infection, such as to promote entry of RxLR effectors into host cells. Our results derived from P. sojae RxLR effector Avr1b confirm that both the N-terminus and the C-terminus of this effector can bind PtdIns(3)P.

  8. Identification of cell wall-associated proteins from Phytophthora ramorum

    NARCIS (Netherlands)

    Meijer, H.J.G.; Vondervoort, van de P.J.I.; Yin, Q.Y.; Koster, de C.G.; Klis, F.M.; Govers, F.; Groot, de P.W.J.

    2006-01-01

    The oomycete genus Phytophthora comprises a large group of fungal-like plant pathogens. Two Phytophthora genomes recently have been sequenced; one of them is the genome of Phytophthora ramorum, the causal agent of sudden oak death. During plant infection, extracellular proteins, either soluble secre

  9. Identification of cell wall-associated proteins from Phytophthora ramorum

    NARCIS (Netherlands)

    Meijer, H.J.G.; Vondervoort, van de P.J.I.; Yin, Q.Y.; Koster, de C.G.; Klis, F.M.; Govers, F.; Groot, de P.W.J.

    2006-01-01

    The oomycete genus Phytophthora comprises a large group of fungal-like plant pathogens. Two Phytophthora genomes recently have been sequenced; one of them is the genome of Phytophthora ramorum, the causal agent of sudden oak death. During plant infection, extracellular proteins, either soluble

  10. Cloning, expression analysis and recombinant expression of a gene encoding a polygalacturonase-inhibiting protein from tobacco, Nicotiana tabacum

    Directory of Open Access Journals (Sweden)

    Chengsheng Zhang

    2016-05-01

    Full Text Available Polygalacturonase inhibiting proteins (PGIPs are major defensive proteins produced by plant cell walls that play a crucial role in pathogen resistance by reducing polygalacturonase (PG activity. In the present study, a novel PGIP gene was isolated from tobacco (Nicotiana tabacum, hereafter referred as NtPGIP. A full-length NtPGIP cDNA of 1,412 bp with a 186 bp 5′-untranslated region (UTR, and 209 bp 3′-UTR was cloned from tobacco, NtPGIP is predicted to encode a protein of 338 amino acids. The NtPGIP sequence from genomic DNA showed no introns and sequence alignments of NtPGIP’s deduced amino acid sequence showed high homology with known PGIPs from other plant species. Moreover, the putative NtPGIP protein was closely clustered with several Solanaceae PGIPs. Further, the expression profile of NtPGIP was examined in tobacco leaves following stimulation with the oomycete Phytophthora nicotianae and other stressors, including salicylic acid (SA, abscisic acid (ABA, salt, and cold treatment. The results showed that all of the treatments up-regulated the expression of NtPGIP at different times. To understand the biochemical activity of NtPGIP gene, a full-length NtPGIP cDNA sequence was subcloned into a pET28a vector and transformed into E. coli BL21 (DE3. Recombinant proteins were successfully induced by 1.0 nmol/L IPTG and the purified proteins effectively inhibited Phytophthora capsici PG activity. The results of this study suggest that NtPGIP may be a new candidate gene with properties that could be exploited in plant breeding.

  11. Diagnostics of Tree Diseases Caused by Phytophthora austrocedri Species.

    Science.gov (United States)

    Mulholland, Vincent; Elliot, Matthew; Green, Sarah

    2015-01-01

    We present methods for the detection and quantification of four Phytophthora species which are pathogenic on trees; Phytophthora ramorum, Phytophthora kernoviae, Phytophthora lateralis, and Phytophthora austrocedri. Nucleic acid extraction methods are presented for phloem tissue from trees, soil, and pure cultures on agar plates. Real-time PCR methods are presented and include primer and probe sets for each species, general advice on real-time PCR setup and data analysis. A method for sequence-based identification, useful for pure cultures, is also included.

  12. 75 FR 44936 - Notice of Request for Extension of Approval of an Information Collection; Phytophthora Ramorum...

    Science.gov (United States)

    2010-07-30

    ...; Phytophthora Ramorum; Quarantine and Regulations AGENCY: Animal and Plant Health Inspection Service, USDA... regulations for the interstate movement of regulated articles to prevent the spread of Phytophthora ramorum... of Phytophthora ramorum, contact Mr. Prakash Hebbar, Program Manager, Emergency and Domestic...

  13. Beperking van de aansprakelijkheid van accountants

    NARCIS (Netherlands)

    Wallage, P.

    2008-01-01

    De beperking van de aansprakelijkheid van accountants staat momenteel wereldwijd hoog op de agenda van wet- en regelgevers. Reden is de angst dat door toekenning van onevenredig hoge claims een van de 'big 4' accountantskantoren zou kunnen omvallen. De grote vier bestaan uit de internationaal georga

  14. Toepassing van maaimeststoffen - Van Strien, 2011

    NARCIS (Netherlands)

    Burgt, van der G.J.H.M.; Rietberg, P.

    2012-01-01

    Dit is het eerste tussentijdse verslag van onderzoek naar de optimalisatie van bedrijfsinterne mineralenstromen. Het onderzoek vond plaats op het bedrijf van Joost van Strien. Gezien het feit dat dit het eerste jaar is van een meerjarig onderzoek gaat het vooral om het vastleggen en beschikbaar hebb

  15. Voedingswaarde van planten - gewichtstoename van rupsen. Experiment

    NARCIS (Netherlands)

    Huisman, T.; Loon, van J.; Hemerik, L.

    2005-01-01

    Het doel van dit experiment is het bepalen van het effect van voedseltype op gewichtstoename. Om zo’n effect vast te stellen op een wetenschappelijke manier, worden de gegevens geanalyseerd met de Wilcoxon tweesteekproeventoets

  16. Bereiding van bilirubinestandaarden

    NARCIS (Netherlands)

    Dreumel; H.J.van; Bosman; H.A.; Derks; H.J.G.M.; Hagen-Fast; A.K.; Koedam; J.C.; Klaasen; R.; Phielix-Strubbe; C.J.; Terlingen; J.B.A.

    1986-01-01

    Dit rapport beschrijft de bereiding van vijf partijen gevriesdroogde bilirubinestandaard. De volumeverandering die optreedt tengevolge van droogvriezen en reconstitutie kon worden berekend aan de hand van bepalingen van bilirubine, kalium, chloride en radioactiviteitsmetingen in de oorspronkelij

  17. Katalytisch verbranden van varkensmest

    NARCIS (Netherlands)

    Hendriks, J.

    1995-01-01

    Door het verbranden van mest kan het mestvolume worden verkleind. Binnenkort gaat op het Varkensproefbedrijf 'Zuid- en West-Nederland' in Sterksel onderzoek van start om de mogelijkheden van het katalytisch verbranden van varkensmest te bekijken.

  18. Phytophthora porri in leek: epidemiology and resistance.

    NARCIS (Netherlands)

    Smilde, W.D.

    1996-01-01

    In winter, Phytophthora porri is an important pathogen of leek ( Allium porrum L.) in the Netherlands. The fungus survives the crop-free period in summer by oospores in soil, and infects the leaves in autumn. Field studies indicated that dispersal by rain splash is crucial for initiation of an epid

  19. Tomato late blight (Phytophthora infestans) in Uganda

    NARCIS (Netherlands)

    Tumwine, J.; Frinking, H.D.; Jeger, M.J.

    2002-01-01

    A survey on the tomato late blight situation and current practices for disease management was carried out in Uganda using an informal structured questionnaire approach. Ten districts from different agroclimatic zones were selected for the survey. Phytophthora infestans isolates from tomatoes were ob

  20. The nature of biotrophy in Phytophthora infestans

    NARCIS (Netherlands)

    Scheepens, P.C.

    1978-01-01

    Phytophthora infestans, being an intermediate type between the facultative and obligate parasites among the Peronosporales (class Oomycetes ), was used to study the factors which are responsible for the inability of

  1. Hot spots of Phytophthora in commercial nurseries

    Science.gov (United States)

    Corina Junker; Patrick Goff; Stefan Wagner; Sabine Werres

    2017-01-01

    Studies have shown that nurseries are an important source for the spread of Phytophthora. Most surveys and studies focusing on the epidemiology of these pathogens in nurseries are based on sampling of symptomatic plants or on samples like water of different sources used for irrigation. There is little knowledge, however, on the survival and...

  2. Variation in Phytophthora infestans : sources and implications

    NARCIS (Netherlands)

    Flier, W.

    2001-01-01

    The oomycete pseudofungus Phytophthora infestans (Mont.) de Bary, the causal organism of late blight, is considered to be one of the most devastating pathogens affecting potatoes and tomatoes worldwide. In Europe, the pathogen caused severe epidemics on potatoes after its introduction in 1845. Late

  3. Phytophthora Genome Sequences Uncover Evolutionary Origins and Mechanisms of Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Lamour, Kurt H [ORNL; McDonald, W Hayes [ORNL; Savidor, Alon [ORNL

    2006-01-01

    Genome sequences of the soybean pathogen, Phytophthora sojae, and the sudden oak death pathogen, Phytophthora ramorum, suggest a photosynthetic past and reveal recent massive expansion and diversification of potential pathogenicity gene families. Abstract: Draft genome sequences of the soybean pathogen, Phytophthora sojae, and the sudden oak death pathogen, Phytophthora ramorum, have been determined. O mycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms and the presence of many Phytophthora genes of probable phototroph origin support a photosynthetic ancestry for the stramenopiles. Comparison of the two species' genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors and, in particular, a superfamily of 700 proteins with similarity to known o mycete avirulence genes.

  4. Energiebesparing bij de bewaring van plantgoed van tulp door temperatuurintegratie

    NARCIS (Netherlands)

    Gude, H.; Dijkema, M.H.G.E.

    2006-01-01

    Onderzoek naar de mogelijkheden van TI (temperatuurintegratie) bij de bewaring van tulpenplantgoed door het vaststellen van de tolerantie van enkele cultivars voor verhogingen van de dagtemperatuur en verlagingen van de nachttemperatuur

  5. Phytophthora Genome Sequences Uncover Evolutionary Origins and Mechanisms of Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathy, Sucheta; Zhang, Xuemin; Dehal, Paramvir; Jiang, Rays H. Y.; Aerts, Andrea; Arredondo, Felipe D.; Baxter, Laura; Bensasson, Douda; Beynon, JIm L.; Chapman, Jarrod; Damasceno, Cynthia M. B.; Dorrance, Anne E.; Dou, Daolong; Dickerman, Allan W.; Dubchak, Inna L.; Garbelotto, Matteo; Gijzen, Mark; Gordon, Stuart G.; Govers, Francine; Grunwald, NIklaus J.; Huang, Wayne; Ivors, Kelly L.; Jones, Richard W.; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt H.; Lee, Mi-Kyung; McDonald, W. Hayes; Medina, Monica; Meijer, Harold J. G.; Nordberg, Erik K.; Maclean, Donald J.; Ospina-Giraldo, Manuel D.; Morris, Paul F.; Phuntumart, Vipaporn; Putnam, Nicholas J.; Rash, Sam; Rose, Jocelyn K. C.; Sakihama, Yasuko; Salamov, Asaf A.; Savidor, Alon; Scheuring, Chantel F.; Smith, Brian M.; Sobral, Bruno W. S.; Terry, Astrid; Torto-Alalibo, Trudy A.; Win, Joe; Xu, Zhanyou; Zhang, Hongbin; Grigoriev, Igor V.; Rokhsar, Daniel S.; Boore, Jeffrey L.

    2006-04-17

    Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oömycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora genes of probable phototroph origin supports a photosynthetic ancestry for the stramenopiles. Comparison of the two species' genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors, and, in particular, a superfamily of 700 proteins with similarity to known oömycete avirulence genes.

  6. A potato pathogenesis-related protein gene, StPRp27, contributes to race-nonspecific resistance against Phytophthora infestans.

    Science.gov (United States)

    Shi, Xiaolei; Tian, Zhendong; Liu, Jun; van der Vossen, Edwin A G; Xie, Conghua

    2012-02-01

    Late blight caused by Phytophthora infestans is the most important disease of potato. Many efforts have been made to understand molecular mechanism of the durable resistance to address the challenge raised by rapid evolution of the pathogen. A pathogenesis related protein (PR) gene StPRp27 was previously isolated from the potato leaves challenged by P. infestans. The sequence analysis and expression pattern reveal that StPRp27 may be associated with resistance to P. infestans. In present research, transient expression of StPRp27 in Nicotiana benthamiana enhanced resistance to P. infestans isolates 99189 and PY23 indicating its potential contribution to the disease resistance. These findings were also confirmed by over-expression of StPRp27 in potato cv. E-potato 3, which significantly slowed down the development of the disease after inoculation with a mixture of P. infestans races. Further, silencing of StPRp27 homologous genes in N. benthamiana harboring dominant Phytophthora resistance gene Rpi-blb1 or Rpi-blb2 showed no effects on the resistance triggered by these R genes. Our results suggest that StPRp27 contributes to a race-nonspecific resistance against P. infestans by inhibiting the disease development and has a potential use in selection and breeding for durable resistance to late blight.

  7. Aspekte van die siekepastoraat

    Directory of Open Access Journals (Sweden)

    H. J. C. Pieterse

    1980-06-01

    Full Text Available Die siekepastoraat vra ons aandag in hierdie tyd omdat die versorging van siekes ’n kenmerk is van die koms van die koninkryk van God. God se barmhartigheid het in sy volheid tot gelding gekom in die optrede van Jesus Christus. Die volle seën van die heil van die Ryk van God hou ook die versorging van die siekes in. Deur die heilswerk van Christus sien die blindes weer, loop die kreupeles, word melaatses gereinig, hoor die dowes, word dooies opgewek (Luk. 7:22.

  8. Modelsimulaties van het stadsklimaat van Rotterdam

    NARCIS (Netherlands)

    Ronda, R.J.; Steeneveld, G.J.; Hove, van B.

    2010-01-01

    Modelsimulaties zijn uitgevoerd ter inschatting van het Urban Heat Island effect van Rotterdam. Hiervoor is de meest recente versie van het Weather Research & Forecasting (WRF) model gebruikt dat is uitgerust met een Urban Canopy Model. Bovendien is gebruik gemaakt van specifieke stadeigenschapp

  9. Monitoring van verdroging; methodische aspecten van meetnetoptimalisatie

    NARCIS (Netherlands)

    Gaast, van der J.W.J.; Massop, H.T.L.; Heuvelink, G.B.M.

    2005-01-01

    In dit onderzoek (in opdracht van Natuurplanbureau) zijn methodische aspecten van verdrogingsmonitoring onderzocht. Het gaat hierbij om monitoring van de freatische grondwaterstand. Om het verdrogingsprobleem in kaart te brengen zijn op basis van een eenvoudige methode landsdekkende Gt-kaarten gemaa

  10. Distribution of solanesol in Nicotiana tabacum

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chun-jian; ZU Yuan-gang; LI Chun-ying; TIAN Cheng-yu

    2007-01-01

    Solanesol is an important secondary metabolite in Nicotiana tabacum. Distribution of solanesol in Nicotiana tabacum was investigated by High Performance Liquid Chromatography (HPLC) method. The quantitative distribution of solanesol in various organs and tissues of N. Tabacum showed that solanesol content, obviously different in all organs, was 6.8, 18.3, 27.5, 45.8, and 68.0 times higher in leaves than that in the stalks, flowers, seeds, fruits and roots, respectively. The contents of solanesol in various parts of leaf, stalk and flower were determined. The content of solanesol in top leaf, middle leaf and bottom leaf gradually decreased (6.124, 5.813 and 5.687 mg·g-1, respectively) and the content of solanesol in various leaf-parts (leaf apex, leaf middle and leaf base) also gradually decreased. The content of solanesol in top stalk was 1.19 times and 1.92 times higher than that in the middle stalk and the bottom stalk, respectively. The content of solanesol in various tissues of stalk (epidermis, cortex and stele) dramatically decreased. The sepal contained higher concentration of solanesol (1.192 mg·g-1) compared to any other parts in flower. The study will provide the base data for the regulation and control of solanesol,moreover, it will provide the scientific evidences for the rational development and utilization of N. Tabacum resources.

  11. Pathogenicity of Phytophthora isolates originating from several woody hosts in Bulgaria and Poland

    Directory of Open Access Journals (Sweden)

    Lyubenova Aneta B.

    2016-09-01

    Full Text Available Our aim was to examine the virulence of eight Phytophthora isolates belonging to three species (Phytophthora cryptogea, Phytophthora plurivora and Phytophthora quercina obtained from diverse European ecosystems (in Bulgaria, Poland and Germany towards three forest tree hosts – English oak (Quercus robur L., Turkey oak (Quercus cerris L. and European beech (Fagus sylvatica L..

  12. De effectiviteit van tandenpoetsen

    NARCIS (Netherlands)

    van der Weijden, F.; Slot, D.E.

    2013-01-01

    Voor de preventie en behandeling van parodontitis en cariës staat de verwijdering van tandplaque centraal. Verwijderen van tandplaque en de natuurlijke reiniging van het gebit door fysiologische krachten - dat wil zeggen wrijving van de tong en de wangen - is uiterst gering (Lindhe & Wicén, 1969).

  13. Staat van zoonosen 2009

    NARCIS (Netherlands)

    Aalten M; Stenvers O; van Pelt W; Braks M; Schimmer B; Langelaar M; LZO; EPI; cib

    2011-01-01

    De Staat van zoonosen 2009 geeft een overzicht van de trends in het voorkomen bij mens en dier van verschillende zoonosen. De cijfers zijn gebaseerd op de data die jaarlijks gemeld worden aan de Europese Commissie, in het kader van Directive 2003/99/EC, over de monitoring van zoonosen en zoonotische

  14. De hand van Huizinga

    NARCIS (Netherlands)

    Huizinga, Johan

    2009-01-01

    De hand van Huizinga bevat een nieuwe selectie van de belangrijkste essays uit het omvangrijke oeuvre van de wereldberoemde Nederlandse historicus Johan Huizinga. Deze essays en studies zijn geselecteerd op basis van de diverse disciplines waarmee Huizinga zich bezighield - van de Middeleeuwen tot

  15. Effecten van clustering van vliegbewegingen van civiele helikopsters in de omgeving van Den Helder Airport

    NARCIS (Netherlands)

    Smit, C.J.

    2009-01-01

    Den Helder Airport streeft naar een uitbreiding van het aantal vliegbewegingen van "groot verkeer" van 22.000 naar 25.000 per jaar. Een dergelijke verruiming kan tot gevolg hebben dat op bepaalde tijden van de dag, met name in de vroege ochtenduren, een sterke clustering van vliegbewegingen optreedt

  16. De effectiviteit van tandenpoetsen

    NARCIS (Netherlands)

    van der Weijden, F.; Slot, D.E.

    2013-01-01

    Voor de preventie en behandeling van parodontitis en cariës staat de verwijdering van tandplaque centraal. Verwijderen van tandplaque en de natuurlijke reiniging van het gebit door fysiologische krachten - dat wil zeggen wrijving van de tong en de wangen - is uiterst gering (Lindhe & Wicén, 1969). D

  17. Effectieve bestrijding van varroa

    NARCIS (Netherlands)

    Cornelissen, B.; Blacquiere, T.; Steen, van der J.J.M.

    2010-01-01

    De varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze brochure van de WUR biedt informatie over de biologie van varroa, de effecten van varroa op honingbijen en

  18. Phytophthora root rot resistance in soybean E00003

    Science.gov (United States)

    Phytophthora root rot (PRR), caused by the oomycete Phytophthora sojae, is a devastating disease in soybean production. Using resistant cultivars has been suggested as the best solution for disease management. Michigan elite soybean E00003 is resistant to P. sojae and has been used as a PRR resist...

  19. Host and habitat index for Phytophthora species in Oregon

    Science.gov (United States)

    Everett Hansen; Paul Reeser; Wendy Sutton; Laura. Sims

    2012-01-01

    In this contribution we compile existing records from available sources of reliably identified Phytophthora species from forests and forest trees in Oregon, USA. A searchable version of this information may be found in the Forest Phytophthoras of the World Disease Finder (select USA-Oregon). We have included isolations from soil and streams in...

  20. Forest Phytophthora diseases in the Americas: 2007 - 2010

    Science.gov (United States)

    S. J. Frankel; E. M. Hansen

    2011-01-01

    Recent findings, policy, regulation, and management relating to tree disease caused by Phytophthora species in wildlands and nurseries of North and South America are reviewed. These include the isolation of Phytophthora alni uniformis Brasier & S.A.Kirk in Alaska, and detection of population shifts in NA1, NA2 and EU1...

  1. The aspartic proteinase family of three Phytophthora species

    NARCIS (Netherlands)

    Kay, J.; Meijer, H.J.G.; Have, ten A.; Kan, van J.A.L.

    2011-01-01

    Background - Phytophthora species are oomycete plant pathogens with such major social and economic impact that genome sequences have been determined for Phytophthora infestans, P. sojae and P. ramorum. Pepsin-like aspartic proteinases (APs) are produced in a wide variety of species (from bacteria to

  2. Van bulk naar kwaliteit.

    NARCIS (Netherlands)

    Ziggers, G.W.

    1993-01-01

    De uitvoering van het project IKB (Integrale Kwaliteits Beheersing) ondersteunt de marktgerichte produktie van vleeskuikens. Maatregelen moeten waarborgen geven voor een veilig en kwalitatief goed produkt en een stabilizering of vergroting van de afzetmarkt

  3. Aankoopfactoren van vlees

    NARCIS (Netherlands)

    Tacken, G.M.L.

    2001-01-01

    In het kader van het onderzoeksprogramma 'Toekomstige veehouderijsystemen' is onderzoek verricht naar duurzame en economisch haalbare veehouderijconcepten. Daarbij kwam als één van de onderwerpen de aankoopfactoren van vlees aan bod.

  4. Nieuws van het naamgevingsfront

    NARCIS (Netherlands)

    Hoffman, M.H.A.

    2008-01-01

    Wetenschappers en beleidsmakers uit de hele wereld kwamen in Wageningen bijeen om te spreken over naamgeving van cultuurgewassen. Marco Hoffman van PPO Bomen was namens de Nederlandse boomkwekerijsector van de partij en hij selecteerde de belangrijkste onderwerpen.

  5. Bewaring van knolvenkel

    NARCIS (Netherlands)

    Wijk, van C.A.P.; Ligthart, J.

    1993-01-01

    Ter verlenging van de aanvoerperiode van knolvenkel zijn van 1990 t/m '92 bewaarproeven uitgevoerd. Bewaard is bij normale luchtsamenstelling, een hoge relatieve luchtvochtigheid en lage temperatuur (0 tot +1 graden Celsius)

  6. Collectie Van den Bree

    NARCIS (Netherlands)

    Voerman, Gerrit; van den Bree, R.A.P.; Koole, Ruud

    1988-01-01

    Plaatsingslijst behorende bij het persoonlijke archief van R.A.P. van den Bree, betrekking hebbende op de Evangelische Volkspartij {EVP) (1979-1986), opgesteld door R.A.P. van den Bree en G. Voerman, 1987

  7. Ziekte van Lyme : nasleep van een tekenbeet

    NARCIS (Netherlands)

    Broek, P.; Takken, W.

    2012-01-01

    Dit themanummer beschrijft de Ziekte van Lyme en geeft een overzicht over de stand van kennis over deze complexe ziekte in Nederland. De lymeziekte is uniek omdat zij veroorzaakt wordt door een bacterie die een teek als tussengastheer (vector) gebruikt.

  8. Ziekte van Lyme : nasleep van een tekenbeet

    NARCIS (Netherlands)

    Broek, P.; Takken, W.

    2012-01-01

    Dit themanummer beschrijft de Ziekte van Lyme en geeft een overzicht over de stand van kennis over deze complexe ziekte in Nederland. De lymeziekte is uniek omdat zij veroorzaakt wordt door een bacterie die een teek als tussengastheer (vector) gebruikt.

  9. Use of Several Natural Products from Selected Nicotiana Species to Prevent Black Shank Disease in Tobacco

    Directory of Open Access Journals (Sweden)

    Kroumova Antoaneta B.

    2016-07-01

    Full Text Available Black shank is a major annual disease threat to all types of tobacco worldwide. It is caused by the fungus Phytophthora parasitica var. nicotianae (PPN. The major tobacco growing areas in US - Kentucky, Tennessee and North Carolina can experience devastating losses, reaching in some fields up to 100%. Thus far, the main approaches to control this disease have been creation of resistant varieties, fungicide treatments, and crop rotation. Some fungicides are reported to have negative effects on the environment. The goal of this work was to test the antifungal activity of several natural products that are synthesized by certain Nicotiana species, and secreted to the leaf surface. We hypothesized that phylloplanin, cis-abienol, labdenediol and sclareol can suppress PPN-race 0- and PPN-race 1-caused disease in Burley tobaccos KY 14 and MS KY 14 × L8LC in the greenhouse. We developed methods for leaf surface extraction, spore preparation and soil drench application of the natural compounds tested. Experiments were performed on 5–8 week-old greenhouse grown seedlings. cis-Abienol showed high inhibitory properties toward the disease. Race 0 infection was completely subdued in KY 14 while race 1 infection was reduced by 70–80%, and delayed by 6–10 days in KY 14 and MS KY14 × L8LC. Sclareol was very effective in inhibiting race 0-caused disease in both tobacco cultivars. In MS KY 14 × L8LC race 1 infection was inhibited while in KY 14 it was reduced by 85% and delayed by 6 days. Labdenediol reduced the disease by half in eight week-old KY 14 plants. Tobacco phylloplanin reduced plant infection by both races by 50–60% and delayed the disease by 6–10 days. Phylloplanin was least suppressive in both tobacco cultivars. We consider sclareol to be the best candidate for future studies due to its antifungal properties and availability. cis-Abienol, despite its good antifungal activity, is not feasible for large-scale use due to the production and

  10. Variation in capsidiol sensitivity between Phytophthora infestans and Phytophthora capsici is consistent with their host range.

    Science.gov (United States)

    Giannakopoulou, Artemis; Schornack, Sebastian; Bozkurt, Tolga O; Haart, Dave; Ro, Dae-Kyun; Faraldos, Juan A; Kamoun, Sophien; O'Maille, Paul E

    2014-01-01

    Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins.

  11. Phytophthora-ID.org: A sequence-based Phytophthora identification tool

    Science.gov (United States)

    N.J. Grünwald; F.N. Martin; M.M. Larsen; C.M. Sullivan; C.M. Press; M.D. Coffey; E.M. Hansen; J.L. Parke

    2010-01-01

    Contemporary species identification relies strongly on sequence-based identification, yet resources for identification of many fungal and oomycete pathogens are rare. We developed two web-based, searchable databases for rapid identification of Phytophthora spp. based on sequencing of the internal transcribed spacer (ITS) or the cytochrome oxidase...

  12. Variation in capsidiol sensitivity between Phytophthora infestans and Phytophthora capsici is consistent with their host range.

    Directory of Open Access Journals (Sweden)

    Artemis Giannakopoulou

    Full Text Available Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins.

  13. Variation in Capsidiol Sensitivity between Phytophthora infestans and Phytophthora capsici Is Consistent with Their Host Range

    Science.gov (United States)

    Giannakopoulou, Artemis; Schornack, Sebastian; Bozkurt, Tolga O.; Haart, Dave; Ro, Dae-Kyun; Faraldos, Juan A.; Kamoun, Sophien; O’Maille, Paul E.

    2014-01-01

    Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins. PMID:25203155

  14. Transcriptional dynamics of Phytophthora infestans during sequential stages of hemibiotrophic infection of tomato.

    Science.gov (United States)

    Zuluaga, Andrea P; Vega-Arreguín, Julio C; Fei, Zhangjun; Ponnala, Lalit; Lee, Sang Jik; Matas, Antonio J; Patev, Sean; Fry, William E; Rose, Jocelyn K C

    2016-01-01

    Hemibiotrophic plant pathogens, such as the oomycete Phytophthora infestans, employ a biphasic infection strategy, initially behaving as biotrophs, where minimal symptoms are exhibited by the plant, and subsequently as necrotrophs, feeding on dead plant tissue. The regulation of this transition and the breadth of molecular mechanisms that modulate plant defences are not well understood, although effector proteins secreted by the pathogen are thought to play a key role. We examined the transcriptional dynamics of P. infestans in a compatible interaction with its host tomato (Solanum lycopersicum) at three infection stages: biotrophy; the transition from biotrophy to necrotrophy; and necrotrophy. The expression data suggest a tight temporal regulation of many pathways associated with the suppression of plant defence mechanisms and pathogenicity, including the induction of putative cytoplasmic and apoplastic effectors. Twelve of these were experimentally evaluated to determine their ability to suppress necrosis caused by the P. infestans necrosis-inducing protein PiNPP1.1 in Nicotiana benthamiana. Four effectors suppressed necrosis, suggesting that they might prolong the biotrophic phase. This study suggests that a complex regulation of effector expression modulates the outcome of the interaction.

  15. Cloning of genes encoding nonhost hypersensitive response-inducing elicitors from Phytophthora boehmeriae

    Institute of Scientific and Technical Information of China (English)

    LI Jun; ZHANG HaiFeng; ZHANG ZhengGuang; WANG YuanChao; ZHENG XiaoBo

    2007-01-01

    We have devised a high-throughput functional cloning method to isolate cDNAs from Phytophthora boehmeriae of which the products elicit a hypersensitive response (HR) in tobacco. The cDNAs were cloned into a binary potato virus X (PVX)-based expression vector and transformed into Agrobacterium tumefeciens (Mog101). 4100 colonies were individually toothpick-inoculated onto leaflets of Nicotiana benthamiana. 12 cDNAs were identified whose expression induced formation of a necrotic lesion around the inoculation site. 7 of these clones have different sequences. One of these clones PBC43 encodes specific elicitin. Clone PBC163 encodes a protein highly homologous to Rab; PBC241 encodes a prohibitin protein; PBN62 encodes a Heat Shock Protein 60 (HSP60). The other five cDNAs reveal no homology to known protein and are thus considered novel. These observations suggest that this functional screening method is a versatile strategy to identify cDNAs of pathogens that encode elicitors and other HR-inducing proteins.

  16. Phenotypic analysis of Phytophthora parasitica by using high throughput phenotypic microarray.

    Science.gov (United States)

    Wang, Maosheng; Wang, Hancheng; Huang, Yanfei; Wang, Jin; Zhang, Changqing; Lu, Hongxue

    2015-10-04

    We studied the phenotypic characterization of Phytophthora parasitica Dastur var. nicotianae. Phenotypic characterization of the pathogen was studied to provide information for disease management program by using BIOLOG phenotype MicroArray (PM ). Using PM plates 1 to 10, 950 different phenotypic characterizations were tested. P. parasitica was able to metabolize 74% of tested carbon sources, 96% of nitrogen sources, 100% of sulfur sources, and 98% of phosphorus sources. Most informative utilization patterns for carbon sources of P. parasitica were organic acids and carbohydrates, and for nitrogen were various amino acids. The pathogen presented 285 different nitrogen pathways. It had wide range adaptabilities in osmolytes with up to 1% sodium chloride, up to 3% potassium chloride, up to 5% sodium sulfate, up to 20% ethylene glycol, up to 2% sodium formate, up to 5% urea, and up to 2% sodium lactate. It also exhibited active metabolism under pH values between 3.5 and 10, with optimal pH of around 7.0. The pathogen showed both decarboxylase and deaminase activities in the presence of various amino acids. These phenotypic characterizations of P. parasitica provided the theoretical basis for the next study of the pathogen in physiology and metabolism, and provided potential new way for tobacco black shank management.

  17. Detectie van ziektesymptomen met behulp van fluorescentiebeelden

    NARCIS (Netherlands)

    Loon, van P.C.C.

    2004-01-01

    Rapport over de positie van de biologische paddestoelenteelt op intersectoraal en (inter)-regionaal niveau. Het overzicht in tabel- en schemavorm van de stromen grondstoffen en producten verduidelijkt de intersectorale positie van de champignonteelt. Dit kan een aanzet zijn bij het signaleren en opl

  18. Belang van dispersie bij herstel van waternatuur

    NARCIS (Netherlands)

    Didderen, K.; Verdonschot, P.F.M.

    2010-01-01

    Resultaten van herstelmaatregelen in wateren vallen vaak tegen, omdat de gewenste fauna niet (terug)komt. Een belangrijke reden hiervoor is dat (her)kolonisatie van waterfauna moet plaatsvinden vanuit bronpopulaties. Om meer te weten te komen over de dispersie van macrofauna en hun verplaatsing door

  19. Routekeuze van automobilisten : resultaten van een vragenlijstonderzoek.

    NARCIS (Netherlands)

    Goldenbeld, C. Drolenga, J. & Smits, A.

    2007-01-01

    Dit rapport doet verslag van een vragenlijstonderzoek naar routekeuze van automobilisten in de regio Den Haag. Aan meer dan 400 automobilisten uit vier woongebieden op 20-25 km afstand ten noorden van Den Haag is gevraagd welke routes zij regelmatig met de auto naar Den Haag rijden, en welke alterna

  20. Vetzuur- en sterolsamenstelling van zonnebloemolie

    NARCIS (Netherlands)

    Coors, R.G.; Muuse, B.G.

    1981-01-01

    Doel van dit onderzoek is: bepaling van de gemiddelde samenstelling van de vetzuren en sterolen in ruwe zonnebloemolie. Van ca. 50 oliemonsters van zonnebloempitten met bekende herkomst werd de vetzuursamenstelling bepaald, alsmede in enkele monsters het sterolgehalte en de sterolsamenstelling.

  1. Een geschiedenis van vleesloos eten

    NARCIS (Netherlands)

    Dagevos, H.

    2009-01-01

    Recensie van de populaire editie van het proefschrift van Dirk-Jan Verdonk: Het dierloze gerecht: een vegetarische geschiedenis in Nederland. Hierin wordt de geschiedenis van het vegetarisme vanaf de tweede helft van de 19e eeuw tot nu beschreven

  2. Vetzuur- en sterolsamenstelling van zonnebloemolie

    NARCIS (Netherlands)

    Coors, R.G.; Muuse, B.G.

    1981-01-01

    Doel van dit onderzoek is: bepaling van de gemiddelde samenstelling van de vetzuren en sterolen in ruwe zonnebloemolie. Van ca. 50 oliemonsters van zonnebloempitten met bekende herkomst werd de vetzuursamenstelling bepaald, alsmede in enkele monsters het sterolgehalte en de sterolsamenstelling.

  3. Een geschiedenis van vleesloos eten

    NARCIS (Netherlands)

    Dagevos, H.

    2009-01-01

    Recensie van de populaire editie van het proefschrift van Dirk-Jan Verdonk: Het dierloze gerecht: een vegetarische geschiedenis in Nederland. Hierin wordt de geschiedenis van het vegetarisme vanaf de tweede helft van de 19e eeuw tot nu beschreven

  4. Induction of systemic disease resistance in Nicotiana benthamiana by the cyclodipeptides cyclo (l-Pro-l-Pro) and cyclo (d-Pro-d-Pro).

    Science.gov (United States)

    Wu, Liming; Wu, Huijun; Chen, Lina; Zhang, Hongyue; Gao, Xuewen

    2017-01-01

    Cyclodipeptides, formed from two amino acids by cyclodehydration, are produced naturally by many organisms, and are known to possess a large number of biological activities. In this study, we found that cyclo (l-Pro-l-Pro) and cyclo (d-Pro-d-Pro) (where Pro is proline) could induce defence responses and systemic resistance in Nicotiana benthamiana. Treatment with the two cyclodipeptides led to a reduction in disease severity by Phytophthora nicotianae and Tobacco mosaic virus (TMV) infections compared with controls. Both cyclopeptides triggered stomatal closure, induced reactive oxygen species production and stimulated cytosolic calcium ion and nitric oxide production in guard cells. In addition, the application of cyclodipeptides significantly up-regulated the expression of the plant defence gene PR-1a and the PR-1a protein, and increased cellular salicylic acid (SA) levels. These results suggest that the SA-dependent defence pathway is involved in cyclodipeptide-mediated pathogen resistance in N. benthamiana. We report the systemic resistance induced by cyclodipeptides, which sheds light on the potential of cyclodipeptides for the control of plant diseases.

  5. Toetsing van modelberekeningen van uitspoeling van zware metalen uit bodems in het landelijk gebied

    NARCIS (Netherlands)

    Bonten, L.T.C.

    2007-01-01

    Modelberekeningen van de uitspoeling van zware metalen uit bodems in het landelijk gebied zijn getoetst aan de uitspoeling op basis van stoffenbalansen van oppervlaktewatersystemen. Uit de toetsing blijkt dat uitspoeling volgens modelberekeningen niet systematisch afwijkt van uitspoeling op basis va

  6. Berekening van de verwijdering van micro-organismen bij de bereiding van drinkwater

    NARCIS (Netherlands)

    Evers EG; Groennou JTH; MGB; Kiwa

    1999-01-01

    Het microbiologisch gezondheidsrisico van drinkwater wordt gedeeltelijk bepaald door de mate van verwijdering van pathogenen gedurende het zuiveringsproces. In dit rapport worden de huidige beschikbare benaderingen om de mate van verwijdering op basis van data sets te schatten, beschreven en

  7. Kroonjuwelen van de Kaap

    NARCIS (Netherlands)

    Sluiter, L.; Schaminee, J.H.J.

    2012-01-01

    'Kroonjuwelen van de Kaap' neemt de fascinerende wereld van de Kaap onder de loep. Niet alleen de biologische rijkdom van het fynbos, maar ook de geschiedenis van het gebied en zijn bewoners. Na eeuwenlang op zichzelf te hebben geleefd, in nauw samenspel met de natuur, kregen de oorspronkelijke bewo

  8. Economische gevolgen van ontwapening

    NARCIS (Netherlands)

    Duisenberg, Willem Frederik

    1965-01-01

    Samenvatting van de gehele studie 4.1. Economie en ontwapening Ontwapening betekent in deze studie de algehele, snelle afschaffing van alle militaire maatregelen in aIle landen. Het negeren van de politieke waarschijnlijkheden die veeleer wijzen op een zeer geleidelijke afschaffing van slechts

  9. Van afval naar maaltijd

    NARCIS (Netherlands)

    Pereira da Silva, F.I.D.G.

    2013-01-01

    Het doel van het project is om te onderzoeken in hoever het benutten van afval of reststromen voor de productie van, voor mensen geschikt voedsel, haalbaar is. Door middel van een case (uitgevoerd in samenwerking met het bedrijf Smeding) worden een aantal aspecten omtrent de voedselkwaliteit en -vei

  10. Gevolgen van hydrocephalus

    NARCIS (Netherlands)

    Tromp, Cornelis Nicolaas

    1984-01-01

    Hydrocephalus is een aandoening van het centrale zenuwstelsel die de clinicus vrij lang voor grote problemen ten aanzien van de behandeling heeft qesteld. Door de toepassing van de ventriculo-atriale shunttechniek zijn de behandelingsmogelijkheden van hydrocephalus sterk verbeterd. Deze studie probe

  11. Gevolgen van hydrocephalus

    NARCIS (Netherlands)

    Tromp, Cornelis Nicolaas

    1984-01-01

    Hydrocephalus is een aandoening van het centrale zenuwstelsel die de clinicus vrij lang voor grote problemen ten aanzien van de behandeling heeft qesteld. Door de toepassing van de ventriculo-atriale shunttechniek zijn de behandelingsmogelijkheden van hydrocephalus sterk verbeterd. Deze studie

  12. Pyrolyse van acetyleenethers

    NARCIS (Netherlands)

    Rosebeek, Barthelomeus

    1961-01-01

    In het eerste hoofdstuk wordt nader ingegaan op de pyrolyse van acetyleenethers, terwijl er ook de reactie van acetyleenethers met keteen in besproken wordt. Het tweede hoofdstuk handelt over de bereiding van de uitgangsstoffen, de volgende twee hoofdstukken geven de resultaten van de pyrolysereacti

  13. Biochars van dierlijke mest

    NARCIS (Netherlands)

    Ehlert, P.A.I.; Oenema, O.

    2010-01-01

    Informatieposter over Biochars van dierlijke mest. Wereldwijd neemt de belangstelling voor pyrolyse van biomassa toe. Die belangstelling vloeit voort uit de productie van: 1) energie uit hernieuwbare biomassa; 2) grondstoffen voor de chemische industrie, ter vervanging van aardolie; 3) biochar, met

  14. Fysiotherapeutische behandeling van kaakklachten

    NARCIS (Netherlands)

    Visscher, C.M.

    2015-01-01

    In dit artikel worden verschillende behandelmogelijkheden van een orofaciaal fysiotherapeut voor de behandeling van tmd-pijn besproken. Een belangrijk onderdeel van deze behandeling bestaat uit het geven van uitleg over de aandoening en de achterliggende oorzaak, gecombineerd met adviezen over event

  15. Economische gevolgen van ontwapening

    NARCIS (Netherlands)

    Duisenberg, Willem Frederik

    1965-01-01

    Samenvatting van de gehele studie 4.1. Economie en ontwapening Ontwapening betekent in deze studie de algehele, snelle afschaffing van alle militaire maatregelen in aIle landen. Het negeren van de politieke waarschijnlijkheden die veeleer wijzen op een zeer geleidelijke afschaffing van slechts enkel

  16. Het raadsel van Utopia

    NARCIS (Netherlands)

    Berg, F. van den; Poldervaart, S.; Voogd, P. de; Dun, F. van; Bierens, S.; Raak, R. van; Dettingmeijer, R.

    2003-01-01

    Utopieën zijn gedetailleerde ontwerpen voor een andere en betere samenleving. Door de eeuwen heen zijn er talloze utopieën verschenen zoals De Republiek van Plato en Utopia van Thomas More. Ook in de twintigste eeuw zijn er utopieën verschenen als Erewhon van Samuel Butler, Walden Two van

  17. Het effect van huisvesting op het welzijn van paarden

    NARCIS (Netherlands)

    Visser, E.K.

    2007-01-01

    Enkele decennia geleden werd de kennis van paarden nog automatisch overgedragen van vader op zoon, omdat veel families dagelijks met paarden werkten. Eén van de gevolgen van een veranderende manier van houden van en omgaan met paarden is het ontstaan van stress en frustratie. Een aanzienlijk deel va

  18. Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

    Directory of Open Access Journals (Sweden)

    Giovanna GILARDI

    2014-09-01

    Full Text Available Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al to control crown and root rot of tomato incited by Phytophthora nicotianae. The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma, B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

  19. Die wysgerige konsepsie van Thomas van Aquino

    Directory of Open Access Journals (Sweden)

    Thomas Van Aquino

    1976-03-01

    Full Text Available Samevattend is tot dusver die volgende aangetoon: Die werklikheid vertoon volgens Thomas 'n hierargiese struktuur. Daar is verskillende grade van syn. God is die hoogste, die volheid van syn, en by die laere synsniveaus is daar steeds 'n verdere verwydering van hierdie synsvolmaaktheid in die rigting van absolute afwesigheid van syn. Hierdie synshiërargie is volgens die vorm-materieskema opgebou. Die materie in die hoëre synslaag word vorm vir die laere, of omgekeerd: die vorm van die laere is die materie vir die hoëre dinge. God is absoluut suiwer vorm of wet (essensie. Die vorme van die dinge is die goddelike wet (genoem exemplar, similitudo, ratio, verbum of imago wat deur God daarin geskape is. God druk op dié wyse sy gelykenis op kreatuur.like wyse uit. Sy absolute volmaaktheid kan alleen tot uitdrukking gebring word deur 'n veelheid en verskeidenheid van geskape dinge. God word deur Thomas die causa effiaiens en exemplaris genoem. Die verhouding tussen Skepper en geskape werklikheid is dus dié van oorsaak en gevolg. As gevolg van sy wetsidee word daar deur Thomas dus nie duidelik tussen Skepper en skepping onderskei nie, want skepping beteken volgens hom onder andere dat God iets goddeliks (die wet in die dinge lê. Via die goddelike wet in die dinge ingeskape, is daar 'n sekere kontinuiteit tussen God en kosmos.

  20. Aansprakelijkheid : Een teken van kwaliteit

    NARCIS (Netherlands)

    van Lent, L.A.G.M.; Eken, R.C.W.

    1995-01-01

    Het vraagstuk van de aansprakelijkheid van accountants is actueler dan ooit. In het onderliggende artikel wordt een theoretische beschouwing gegeven van de economische gevolgen van het beperken van de aansprakelijkheid van accountants. De beschouwing wordt ondersteund door middel van de uitkomsten v

  1. Mp10 and Mp42 from the aphid species Myzus persicae trigger plant defenses in Nicotiana benthamiana through different activities.

    Science.gov (United States)

    Rodriguez, Patricia A; Stam, Remco; Warbroek, Tim; Bos, Jorunn I B

    2014-01-01

    Aphids are phloem-feeding insects that, like other plant parasites, deliver effectors inside their host to manipulate host responses. The Myzus persicae (green peach aphid) candidate effectors Mp10 and Mp42 were previously found to reduce aphid fecundity upon intracellular transient overexpression in Nicotiana benthamiana. We performed functional analyses of these proteins to investigate whether they activate defenses through similar activities. We employed a range of functional characterization experiments based on intracellular transient overexpression in N. benthamiana to determine the subcellular localization of Mp10 and Mp42 and investigate their role in activating plant defense signaling. Mp10 and Mp42 showed distinct subcellular localization in planta, suggesting that they target different host compartments. Also, Mp10 reduced the levels of Agrobacterium-mediated overexpression of proteins. This reduction was not due to an effect on Agrobacterium viability. Transient overexpression of Mp10 but not Mp42 activated jasmonic acid and salicylic acid signaling pathways and decreased susceptibility to the hemibiotrophic plant pathogen Phytophthora capsici. We found that two candidate effectors from the broad-host-range aphid M. persicae can trigger aphid defenses through different mechanisms. Importantly, we found that some (candidate) effectors such as Mp10 interfere with Agrobacterium-based overexpression assays, an important tool to study effector activity and function.

  2. Genetic transformation of the plant pathogens Phytophthora capsici and Phytophthora parasitica.

    Science.gov (United States)

    Bailey, A M; Mena, G L; Herrera-Estrella, L

    1991-08-11

    Phytophthora capsici and P.parasitica were transformed to hygromycin B resistance using plasmids pCM54 and pHL1, which contain the bacterial hygromycin B phosphotransferase gene (hph) fused to promoter elements of the Ustilago maydis heat shock hsp70 gene. Enzymes Driselase and Novozyme 234 were used to generate protoplasts which were then transformed following exposure to plasmid DNA and polyethylene glycol 6000. Transformation frequencies of over 500 transformants per micrograms of DNA per 1 x 10(6) protoplasts were obtained. Plasmid pCM54 appears to be transmitted in Phytophthora spp. as an extra-chromosomal element through replication, as shown by Southern blot hybridization and by the loss of plasmid methylation. In addition, transformed strains retained their capacity of infecting Serrano pepper seedlings and Mc. Intosh apple fruits, the host plants for P.capsici and P.parasitica, respectively.

  3. Genetic transformation of the plant pathogens Phytophthora capsici and Phytophthora parasitica.

    OpenAIRE

    Bailey, A. M.; Mena, G L; Herrera-Estrella, L

    1991-01-01

    Phytophthora capsici and P.parasitica were transformed to hygromycin B resistance using plasmids pCM54 and pHL1, which contain the bacterial hygromycin B phosphotransferase gene (hph) fused to promoter elements of the Ustilago maydis heat shock hsp70 gene. Enzymes Driselase and Novozyme 234 were used to generate protoplasts which were then transformed following exposure to plasmid DNA and polyethylene glycol 6000. Transformation frequencies of over 500 transformants per micrograms of DNA per ...

  4. Het planetarium van Hartog van Laun

    Directory of Open Access Journals (Sweden)

    Hans Hooijmaaijers

    2009-12-01

    Full Text Available The instrument maker Hartog van Laun devised a special table for an orrery, a lunarium and a tellurium. Van Laun made these instruments for educational purposes, but what makes his planetariums so interesting is the great variety and accuracy of demonstrations one can perform with them. In this paper I will deal with Van Laun and his instrument makers business. I will outline the design of the planetarium and some of the firm’s other instruments. Furthermore I will demonstrate that the detailed description of the planetarium made by Professor Jan Hendrik van Swinden boosted the spread of the instrument.

  5. Espécies de Phytophthora associadas à gomose em pomares de citros no Estado do Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Marilda Pereira Caixeta

    2013-12-01

    Full Text Available A gomose dos citros é considerada uma doença de grande importância para a citricultura no Brasil e em nível mundial. A etiologia desta doença compreende um complexo de espécies de Phytophthora. Embora importante, pouco se conhece sobre a gomose nas regiões produtoras de citros no Estado do Paraná. Por isso, este trabalho teve como objetivo identificar espécies de Phytophthora associadas à gomose em pomares de citros no Paraná. Nas regiões Norte, Noroeste e Vale do Ribeira foram retiradas amostras de raízes de plantas com sintomas de gomose e também de solo da rizosfera. Em laboratório, empregando pêra cv. D'anjou como isca e meio de cultivo batata-dextrose-ágar, foram obtidos 21 isolados de Phytophthora spp. Todos os isolados infectaram mudas de limão 'Cravo', reproduzindo os sintomas de gomose e também apresentaram crescimento micelial a 8º C e a 36º C, com exceção do isolado PR20 para 36º C . "In vitro", esses isolados foram heterotálicos, sendo 20 compatíveis ao tipo padrão A2 e um compatível ao tipo padrão A1. Vinte isolados formaram esporângios persistentes e papilados, com 25,5 - 62,0 µm de comprimento (C e 27,9 - 49,6 µm de largura (L e a relação C/L foi de 1,38:1. Um isolado (PR20 apresentou esporângios medindo 40,3 - 55,8 µm de comprimento e 27,9 - 37,2 µm de largura, formando esporângios persistentes, papilados ou bipapilados e de formas distorcidas, não formando clamidósporos. A temperatura ótima para crescimento desse isolado foi entre 20 a 28º C, enquanto para os demais foi de 24 a 32º C, tendo estes produção abundante de clamidósporos globosos de diâmetro variando entre 21,7 a 43,4 µm. De acordo com as características morfofisiológicas apresentadas, dos 21 isolados analisados, 20 pertenceram à espécie P. nicotianae e um à espécie P. citrophthora. A análise de sequências de genes da região ITS1-5.8S-ITS2 do rDNA e usando o teste de "Single-Strand Conformation Polymorphism

  6. Phytophthora species, new threats to the plant health in Korea.

    Science.gov (United States)

    Hyun, Ik-Hwa; Choi, Woobong

    2014-12-01

    Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

  7. Evaluation of Watermelon Germplasm for Resistance to Phytophthora Blight Caused by Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Min-Jeong Kim

    2013-03-01

    Full Text Available This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension (10⁶ sporangia/ml. At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840 showed moderate resistance and two accessions (IT185446 and IT187904 were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

  8. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Mee Kyung Sang

    2013-06-01

    Full Text Available We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107 among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05 reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05 reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

  9. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici

    Science.gov (United States)

    Sang, Mee Kyung; Shrestha, Anupama; Kim, Du-Yeon; Park, Kyungseok; Pak, Chun Ho; Kim, Ki Deok

    2013-01-01

    We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05) reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05) reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit. PMID:25288942

  10. Genetic variation in alkaloid accumulation in leaves of Nicotiana

    Institute of Scientific and Technical Information of China (English)

    Bo SUN; Fen ZHANG; Guo-jun ZHOU; Guo-hai CHU; Fang-fang HUANG; Qiao-mei WANG; Li-feng JIN; Fu-cheng LIN; Jun YANG

    2013-01-01

    Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from al six genotypes via gas chromatograph-mass spectrometry (GC-MS). Significant differences in alkaloid content were ob-served both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated (R2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.

  11. Genetic variation in alkaloid accumulation in leaves of Nicotiana.

    Science.gov (United States)

    Sun, Bo; Zhang, Fen; Zhou, Guo-jun; Chu, Guo-hai; Huang, Fang-fang; Wang, Qiao-mei; Jin, Li-feng; Lin, Fu-cheng; Yang, Jun

    2013-12-01

    Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry (GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated (R(2)=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.

  12. Pollen irradiation and possible gene transfer in Nicotiana species

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1985-01-01

    Progeny from crosses of Nicotiana langsdorffii with gamma irradiated pollen of Nicotiana alata ‘Crimson Bedder’ showed skewed segregation in the F2 favoring the maternal parent. This is probably not gene transfer in a strict sense, rather just an extreme case of reduced transmission of irradiated...... chromosomes, leading to massive overrepresentation of maternal genes. Gene transfer or mutational loss may explain some anomalous F1 plants. Segregation in the F2 progeny showed the presence of several genes from the irradiated pollen. Crosses of Nicotiana sylvestris, N. plumbaginifolia N. paniculata......, and Petunia parodii with irradiated pollen from N. alata and Petunia hybrida showed no evidence of gene transfer, nor did experiments with irradiated mentor pollen. This indicates that gene transfer with irradiated pollen between non-crossing species or between species giving sterile hybrids is probably...

  13. Overexpression of GmERF5, a new member of the soybean EAR motif-containing ERF transcription factor, enhances resistance to Phytophthora sojae in soybean.

    Science.gov (United States)

    Dong, Lidong; Cheng, Yingxin; Wu, Junjiang; Cheng, Qun; Li, Wenbin; Fan, Sujie; Jiang, Liangyu; Xu, Zhaolong; Kong, Fanjiang; Zhang, Dayong; Xu, Pengfei; Zhang, Shuzhen

    2015-05-01

    Phytophthora root and stem rot of soybean [Glycine max (L.) Merr.], caused by Phytophthora sojae Kaufmann and Gerdemann, is a destructive disease throughout the soybean planting regions in the world. Here, we report insights into the function and underlying mechanisms of a novel ethylene response factor (ERF) in soybean, namely GmERF5, in host responses to P. sojae. GmERF5-overexpressing transgenic soybean exhibited significantly enhanced resistance to P. sojae and positively regulated the expression of the PR10, PR1-1, and PR10-1 genes. Sequence analysis suggested that GmERF5 contains an AP2/ERF domain of 58 aa and a conserved ERF-associated amphiphilic repression (EAR) motif in its C-terminal region. Following stress treatments, GmERF5 was significantly induced by P. sojae, ethylene (ET), abscisic acid (ABA), and salicylic acid (SA). The activity of the GmERF5 promoter (GmERF5P) was upregulated in tobacco leaves with ET, ABA, Phytophthora nicotianae, salt, and drought treatments, suggesting that GmERF5 could be involved not only in the induced defence response but also in the ABA-mediated pathway of salt and drought tolerance. GmERF5 could bind to the GCC-box element and act as a repressor of gene transcription. It was targeted to the nucleus when transiently expressed in Arabidopsis protoplasts. GmERF5 interacted with a basic helix-loop-helix transcription factor (GmbHLH) and eukaryotic translation initiation factor (GmEIF) both in yeast cells and in planta. To the best of our knowledge, GmERF5 is the first soybean EAR motif-containing ERF transcription factor demonstrated to be involved in the response to pathogen infection.

  14. Gedrag van gechloreerde koolwaterstoffen in de bodem ; resultaten van kolomproeven

    NARCIS (Netherlands)

    Lagas; P.; Snell; M.C.; Kappers; F.I.; Pool; W.G.; Berg; S. van den

    1986-01-01

    Het gedrag van gechloreerde koolwaterstoffen in de bodem werd in het laboratorium onder gecontroleerde omstandigheden onderzocht met behulp van grondkolommen van 10 cm. In de kolommen werden profielen opgebouwd van een drietal verschillende grondsoorten: podzol, eerdgrond en veen, met organisch

  15. Bibliografie van de geschiedenis van de Nederlandse tuinarchitectuur 2000

    NARCIS (Netherlands)

    Dijkstra, A.; Missel, L.

    2001-01-01

    Deze bibliografie is een selectie van publicaties over de geschiedenis van tuinen, parken, buitenplaatsen, begraafplaatsen en groenvoorzieningen. Deze titels vormen een onderdeel van een bestand TUINPAD van ruim 2200 titels, die via internet te raadplegen zijn

  16. ANORMALIDADES EN FLORES DE NICOTIANA

    Directory of Open Access Journals (Sweden)

    Raúl Martínez Crovetto

    2010-11-01

    Full Text Available

    En este trabajo se describen las siguientes anormalidades florales: la adherencia de tallos florales, spirody, dialysepaly, dialypetaly, staminodiody, petalody de estambre y la supresión de estilo en Nicotiana rustica, y dialysepaly, dialypetaly, dialycarpely, supresión de estilo y staminody del sépalo en Nicotiana tabacum. Algunos de estos términos se proponen por primera vez por los fenómenos teratológicos.

  17. 78 FR 58993 - Notice of Request for Extension of Approval of an Information Collection; Phytophthora Ramorum...

    Science.gov (United States)

    2013-09-25

    ... Collection; Phytophthora Ramorum; Quarantine and Regulations AGENCY: Animal and Plant Health Inspection... Phytophthora ramorum. DATES: We will consider all comments that we receive on or before November 25, 2013... of regulated articles to prevent the spread of Phytophthora ramorum, contact Dr. Prakash K....

  18. 40 CFR 180.1057 - Phytophthora palmivora; exemption from requirement of tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Phytophthora palmivora; exemption from... From Tolerances § 180.1057 Phytophthora palmivora; exemption from requirement of tolerance. Phytophthora palmivora is exempted from the requirement of a tolerance in or on the raw agricultural...

  19. Risico voor resistente rassen, Phytophthora doorbreekt resisten tiegen (interview met Geert Kessel)

    NARCIS (Netherlands)

    Engwerda, J.; Kessel, G.J.T.

    2009-01-01

    In phytophthora-resistente aardappelrassen Bionica en Toluca kan alsnog phytoph-thora ontstaan. Wageningen UR waarschuwt telers hiervoor. Bij laboratoriumexperimenten zijn drie phytophthora-isolaten gevonden die het resistentiegen Blb2 hebben doorbroken. Het is voor het eerst dat de aardappelziekte

  20. De acceptatie van innovaties in de context van een netwerksamenleving

    NARCIS (Netherlands)

    Hillebrand, B.; Driessen, P.H.; Kok, R.A.W.

    2010-01-01

    De acceptatie van nieuwe producten is in de literatuur uitgebreid bestudeerd. Maar er is weinig aandacht besteed aan de acceptatie van nieuwe producten in de context van een netwerksamenleving. In een netwerksamenleving hangt de acceptatie van een nieuw product niet alleen af van de bereidheid van k

  1. Mogelijkheden tot productie van beertjes

    NARCIS (Netherlands)

    Scholten, R.; Huiskes, J.

    1994-01-01

    In opdracht van het Produktschap Vee en Vlees is het project Mogelijkheden tot productie van vleesbeertjes en afzet van vlees en vleesproducten hiervan uitgevoerd. De afzetmogelijkheden voor vlees van beertjes zijn en blijven vooralsnog minimaal

  2. De metamorfoses van het Justus van Effencomplex

    NARCIS (Netherlands)

    Van Emstede, C.I.C.

    2012-01-01

    De Justus van Effencomplex in Spangen, dat architect Michiel Brinkman in 1918 ontwierp, werd in 1985 bijgeschreven in het monumentenregister. Een ingrijpende renovatie vondplaats tussen 1983 en 1989 in het kader van de Rotterdamse stadsvernieuwing. In 2010 was het complex echter opnieuw in zo een

  3. De effectiviteit van daltononderwijs

    NARCIS (Netherlands)

    van der Zee, Symen

    2015-01-01

    In dit proefschrift is de effectiviteit van daltononderwijs onderzocht. De eerste vraag waarop is ingegaan, is waarom daltononderwijs focust op effectiviteit. De belangrijkste reden hiervoor blijkt de discussie in de samenleving te zijn over de doeltreffendheid van vernieuwend onderwijs. Vervolgens

  4. Microbieel aanzuren van vleesvarkensmest

    NARCIS (Netherlands)

    Hendriks, J.; Vrielink, M.

    1994-01-01

    Het Praktijkonderzoek Varkenshouderij onderzoekt op het Varkensproefbedrijf te Raalte het effect van het microbieel aanzuren van vleesvarkensmest op de ammoniakemissie. Hierbij wordt de mest aangezuurd met melkzuur, geproduceerd door melkzuurbacteriën.

  5. Weidegang van geiten

    NARCIS (Netherlands)

    Eekeren, van N.J.M.

    2011-01-01

    Weidegang is belangrijk voor het welzijn van geiten. Daarmee is het een essentieel onderdeel van de bedrijfsvoering en bovendien onderscheidend voor de biologische geitenhouderij. Helaas levert weidegang bij geiten ook een aantal knelpunten op zoals: het risico op een maagdarmwormenbesmetting,

  6. Benaderingen van over

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In dit hoofdstuk wordt de relatie tussen de betekenissen van het Nederlandse voorzetsel over en een aantal corpora bestudeerd. Het hoofdstuk begint met een analyse van de voorbeelden uit Uit het leven van Dik Trom (1891); daarna wordt de woordenboekinformatie behandeld en vergeleken me

  7. Bronnen van diffuse bodembelasting

    NARCIS (Netherlands)

    Lijzen JPA; Ekelenkamp A; LBG; DGM/BO

    1995-01-01

    Ten behoeve van het preventieve bodembeleid was onvoldoende duidelijk welke bijdrage diverse bronnen leveren aan diffuse bodembelasting. Doel van deze inventarisatie was beschikbare kennis over diffuse bodembelasting te bundelen en kennis-lacunes aan te geven. Nevendoel is het beschrijven van de

  8. Handelsstromen van pluimveevlees

    NARCIS (Netherlands)

    Tacken, G.M.L.; Horne, van P.L.M.

    2006-01-01

    Dit onderzoek geeft inzicht in de goederenstromen van (rauw) pluimveevlees binnen en vooral naar Nederland en de daarmee gepaard gaande zoönoserisico's. Het onderzoek biedt input voor het nog op te zetten controlebeleid, waarmee handhaving van het beleidsvoornemen om het aanbieden van rauw pluimveev

  9. Certificering van biologische restaurants

    NARCIS (Netherlands)

    Soethoudt, J.M.

    2006-01-01

    In Nederland zijn meer dan 100 restaurants, die zichzelf als biologisch restaurant presenteren. Echter, de betekenis van 'biologisch restaurant' is niet gedefinieerd, zodat de consument niet weet waar hij op kan rekenen. Het idee, ontstaan bij Eric van Veluwen van Kasteel Rhederoord, tot verkenning

  10. Handelsstromen van pluimveevlees

    NARCIS (Netherlands)

    Tacken, G.M.L.; Horne, van P.L.M.

    2006-01-01

    Dit onderzoek geeft inzicht in de goederenstromen van (rauw) pluimveevlees binnen en vooral naar Nederland en de daarmee gepaard gaande zoönoserisico's. Het onderzoek biedt input voor het nog op te zetten controlebeleid, waarmee handhaving van het beleidsvoornemen om het aanbieden van rauw

  11. Het telefoonnummer van God

    NARCIS (Netherlands)

    Jansen, J.J.G.

    2004-01-01

    Er zijn duizenden moslims die twijfelen. Die er aan twijfelen of de verschrikkingen van de Hel wel echt bestaan. Die niet zeker weten of de Koran wel precies het letterlijke woord van God is. Die zich afvragen op de profeet van de islam, Mohammed (570-632), nog wel een goed voorbeeld vormt voor de

  12. Teelt van hybride wintertarwerassen

    NARCIS (Netherlands)

    Timmer, R.D.; Paauw, J.G.M.

    2003-01-01

    Om de mogelijkheden van de teelt van hybride wintertarwerassen onder Nederlandse omstandigheden in beeld te brengen zijn er van 2000-2002 proeven uitgevoerd op het PPO-proefbedrijf te Lelystad. In deze proeven zijn een 4-tal hybriderassen (Hybnos, Hyno-braba, Hyno-esta, Mercury) vergeleken met een s

  13. Certificering van biologische restaurants

    NARCIS (Netherlands)

    Soethoudt, J.M.

    2006-01-01

    In Nederland zijn meer dan 100 restaurants, die zichzelf als biologisch restaurant presenteren. Echter, de betekenis van 'biologisch restaurant' is niet gedefinieerd, zodat de consument niet weet waar hij op kan rekenen. Het idee, ontstaan bij Eric van Veluwen van Kasteel Rhederoord, tot verkenning

  14. Van landbouw naar landschap

    NARCIS (Netherlands)

    Pessers, D.W.J.M.; Kistenkas, F.H.

    2010-01-01

    De weg van de aloude Mansholt doctrine naar een geheel nieuw Europees Gemeenschappelijk Landbouwbeleid (GBL) is lang. Het voordeel van de huidige mervoudige crisis kan evenwel zijn dat er eindelijk ens schot komt in de omvorming van de traditionele kwantiteitslandbouw naar een duurzame kwaliteitslan

  15. Idola van de crossmedia

    NARCIS (Netherlands)

    Vliet, H.M.M. van; Twisk, Job; Winkel, Kees; Fröling, Hans; Bakker, Geeske; Hekman, Erik

    2008-01-01

    De uitingen van de crossmedia dringen zich steeds nadrukkelijker aan ons op. Een toenemend aantal crossmedia diensten en producten doet een beroep op onze aandacht en financiën: van interactieve televisieprogramma’s op websites, tot themakanalen op mobiele apparaten, fysieke bijeenkomsten van on

  16. Benaderingen van over

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In dit hoofdstuk wordt de relatie tussen de betekenissen van het Nederlandse voorzetsel over en een aantal corpora bestudeerd. Het hoofdstuk begint met een analyse van de voorbeelden uit Uit het leven van Dik Trom (1891); daarna wordt de woordenboekinformatie behandeld en vergeleken

  17. Het nut van stadsgroen

    NARCIS (Netherlands)

    Hop, M.E.C.M.

    2013-01-01

    In de afgelopen jaren is de belangstelling voor de functies van beplanting in de stad sterk toegenomen. Want deze zogenaamde ecosysteemdiensten blijken belangrijk te zijn voor de leefbaarheid van de stad. PPO geeft een overzicht van de recente bevindingen op dit gebied, gebaseerd op het “Themaonderz

  18. Benaderingen van over

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In dit hoofdstuk wordt de relatie tussen de betekenissen van het Nederlandse voorzetsel over en een aantal corpora bestudeerd. Het hoofdstuk begint met een analyse van de voorbeelden uit Uit het leven van Dik Trom (1891); daarna wordt de woordenboekinformatie behandeld en vergeleken me

  19. Mapping the Progression of Phytophthora Ramorum

    Science.gov (United States)

    Banh, T.; Li, J.; El-Askary, H. M.

    2013-12-01

    There has been a plant pathogen, Phytophthora Ramorum that has been causing trouble for the plant species in the forests of California and Oregon. Phytophthora is essentially a water mold that infects oak species like California black oak, coast live oak as well as California bay laurel (Lamsal). What this project aims to accomplish is to observe any changes in NDVI values between the years of 2002 and 1994. What the project hopes to observe is a decline of NDVI values between the two years because the infection of Phytophtora Ramorum will cause stress to the plant or kill the plant, which will lower the values of NDVI. The project will utilizes satellite data to create NDVI images over the study area and two types of change detection methods to observe the differences between the NDVI values of the two years. Preliminary results for the project, data obtained from Landsat 7 ETM+ with a resolution of 240 meters, was not able to observe any significant changes. A finer resolution to differentiate the NDVI values would be needed. In addition the best way to keep the pathogen from getting out of control is with ground level management, or complete eradication of the pathogen. These eradication methods include burning the infected host plants and spreading herbicide (Alexander). With that in mind it would be ideal to have an early detection of the pathogen infestation. Therefore another goal of the project is to continue to research if remote sensing could play a role in an early detection method for the presence of Phytophtora Ramorum.

  20. Emissies en bestrijdingsmaatregelen van ammoniak

    NARCIS (Netherlands)

    Laurier; M.B.H.M.

    1984-01-01

    In dit rapport wordt een overzicht gegeven van ammoniakemissies en van rendementen en kosten van maatregelen om deze te bestrijden. Op basis van gegevens van het Centraal Planbureau is een project voor 1990 en 2000 gemaakt van de mestproduktie en daarmee samenhangde ammoniakuitworp op landelijke

  1. Silicon delays tobacco Ringspot virus systemic symptoms in Nicotiana tabacum

    Science.gov (United States)

    Soluble silicon (Si) provides protection to plants against a variety of abiotic and biotic stress. However, the role of Si in viral infections has been elusive. To investigate the role of Si in viral infections, hydroponic studies were conducted in Nicotiana tabacum with two pathogens: Tobacco rings...

  2. Antinuclear human autoantibodies as markers in Nicotiana tabacum pollen tubes

    Directory of Open Access Journals (Sweden)

    C. Poggialini

    2014-02-01

    Full Text Available In the present paper we report on the use of antinuclear human autoantibodies as specific markers in Nicotiana tabacum pollen tubes. The antibodies have been tested by fluorescence techniques using a confocal laser scanning microscope. All the antibodies showed specifc labelling pattern and the results, although preliminary in nature, could open new perspectives of research.

  3. Een analyse van kosten en baten van de invoering van latexvrije handschoenen in ziekenhuizen

    NARCIS (Netherlands)

    Bovenkamp, J.M. van de; Gallis, R.; Miedema, E.P.

    2003-01-01

    De beroepsziekte ‘latex allergie' komt steeds meer voor. Op verzoek van de branchebegeleidingscommissie in het kader van het arboconvenant algemene ziekenhuizen heeft TNO Arbeid een analyse gemaakt van de kosten en baten van de invoering van non-latex handschoenen. De analyse van kosten en baten ric

  4. Effector genomics accelerates discovery and functional profiling of potato disease resistance and phytophthora infestans avirulence genes.

    Directory of Open Access Journals (Sweden)

    Vivianne G A A Vleeshouwers

    Full Text Available Potato is the world's fourth largest food crop yet it continues to endure late blight, a devastating disease caused by the Irish famine pathogen Phytophthora infestans. Breeding broad-spectrum disease resistance (R genes into potato (Solanum tuberosum is the best strategy for genetically managing late blight but current approaches are slow and inefficient. We used a repertoire of effector genes predicted computationally from the P. infestans genome to accelerate the identification, functional characterization, and cloning of potentially broad-spectrum R genes. An initial set of 54 effectors containing a signal peptide and a RXLR motif was profiled for activation of innate immunity (avirulence or Avr activity on wild Solanum species and tentative Avr candidates were identified. The RXLR effector family IpiO induced hypersensitive responses (HR in S. stoloniferum, S. papita and the more distantly related S. bulbocastanum, the source of the R gene Rpi-blb1. Genetic studies with S. stoloniferum showed cosegregation of resistance to P. infestans and response to IpiO. Transient co-expression of IpiO with Rpi-blb1 in a heterologous Nicotiana benthamiana system identified IpiO as Avr-blb1. A candidate gene approach led to the rapid cloning of S. stoloniferum Rpi-sto1 and S. papita Rpi-pta1, which are functionally equivalent to Rpi-blb1. Our findings indicate that effector genomics enables discovery and functional profiling of late blight R genes and Avr genes at an unprecedented rate and promises to accelerate the engineering of late blight resistant potato varieties.

  5. Optimaal beheer van hakhoutpercelen voor biomassaproductie

    NARCIS (Netherlands)

    Stobbelaar, D.J.

    2011-01-01

    Door het doelbewust inzetten van biomassa kunnen de doelstellingen energieproductie, natuurkwaliteit, cultuurhistorie en gezonde exploitatie van houtige elementen in samen worden opgepakt. Op basis van studentenonderzoek van hogeschool Van Hall / Larenstein blijkt dat de optimale mix van deze vier d

  6. Phytophthora infestans isolates lacking class I ipiO variants are virulent on Rpi-blb1 potato.

    Science.gov (United States)

    Champouret, Nicolas; Bouwmeester, Klaas; Rietman, Hendrik; van der Lee, Theo; Maliepaard, Chris; Heupink, Anika; van de Vondervoort, Peter J I; Jacobsen, Evert; Visser, Richard G F; van der Vossen, Edwin A G; Govers, Francine; Vleeshouwers, Vivianne G A A

    2009-12-01

    A strategy to control the devastating late blight disease is providing potato cultivars with genes that are effective in resistance to a broad spectrum of Phytophthora infestans isolates. Thus far, most late blight resistance (R) genes that were introgressed in potato were quickly defeated. In contrast, the Rpi-blb1 gene originating from Solanum bulbocastanum has performed as an exclusive broad-spectrum R gene for many years. Recently, the RXLR effector family ipiO was identified to contain Avr-blb1. Monitoring the genetic diversity of the ipiO family in a large set of isolates of P. infestans and related species resulted in 16 ipiO variants in three distinct classes. Class I and class II but not class III ipiO variants induce cell death when coinfiltrated with Rpi-blb1 in Nicotiana benthamiana. Class I is highly diverse and is represented in all analyzed P. infestans isolates except two Mexican P. infestans isolates, and these were found virulent on Rpi-blb1 plants. In its C-terminal domain, IPI-O contains a W motif that is essential for triggering Rpi-blb1-mediated cell death and is under positive selection. This study shows that profiling the variation of Avr-blb1 within a P. infestans population is instrumental for predicting the effectiveness of Rpi-blb1-mediated resistance in potato.

  7. Phytophthora infestans RXLR effector PexRD2 interacts with host MAPKKK ε to suppress plant immune signaling.

    Science.gov (United States)

    King, Stuart R F; McLellan, Hazel; Boevink, Petra C; Armstrong, Miles R; Bukharova, Tatyana; Sukarta, Octavina; Win, Joe; Kamoun, Sophien; Birch, Paul R J; Banfield, Mark J

    2014-03-01

    Mitogen-activated protein kinase cascades are key players in plant immune signaling pathways, transducing the perception of invading pathogens into effective defense responses. Plant pathogenic oomycetes, such as the Irish potato famine pathogen Phytophthora infestans, deliver RXLR effector proteins to plant cells to modulate host immune signaling and promote colonization. Our understanding of the molecular mechanisms by which these effectors act in plant cells is limited. Here, we report that the P. infestans RXLR effector PexRD2 interacts with the kinase domain of MAPKKKε, a positive regulator of cell death associated with plant immunity. Expression of PexRD2 or silencing MAPKKKε in Nicotiana benthamiana enhances susceptibility to P. infestans. We show that PexRD2 perturbs signaling pathways triggered by or dependent on MAPKKKε. By contrast, homologs of PexRD2 from P. infestans had reduced or no interaction with MAPKKKε and did not promote disease susceptibility. Structure-led mutagenesis identified PexRD2 variants that do not interact with MAPKKKε and fail to support enhanced pathogen growth or perturb MAPKKKε signaling pathways. Our findings provide evidence that P. infestans RXLR effector PexRD2 has evolved to interact with a specific host MAPKKK to perturb plant immunity-related signaling.

  8. The NLP toxin family in Phytophthora sojae includes rapidly evolving groups that lack necrosis-inducing activity.

    Science.gov (United States)

    Dong, Suomeng; Kong, Guanghui; Qutob, Dinah; Yu, Xiaoli; Tang, Junli; Kang, Jixiong; Dai, Tingting; Wang, Hai; Gijzen, Mark; Wang, Yuanchao

    2012-07-01

    Necrosis- and ethylene-inducing-like proteins (NLP) are widely distributed in eukaryotic and prokaryotic plant pathogens and are considered to be important virulence factors. We identified, in total, 70 potential Phytophthora sojae NLP genes but 37 were designated as pseudogenes. Sequence alignment of the remaining 33 NLP delineated six groups. Three of these groups include proteins with an intact heptapeptide (Gly-His-Arg-His-Asp-Trp-Glu) motif, which is important for necrosis-inducing activity, whereas the motif is not conserved in the other groups. In total, 19 representative NLP genes were assessed for necrosis-inducing activity by heterologous expression in Nicotiana benthamiana. Surprisingly, only eight genes triggered cell death. The expression of the NLP genes in P. sojae was examined, distinguishing 20 expressed and 13 nonexpressed NLP genes. Real-time reverse-transcriptase polymerase chain reaction results indicate that most NLP are highly expressed during cyst germination and infection stages. Amino acid substitution ratios (Ka/Ks) of 33 NLP sequences from four different P. sojae strains resulted in identification of positive selection sites in a distinct NLP group. Overall, our study indicates that expansion and pseudogenization of the P. sojae NLP family results from an ongoing birth-and-death process, and that varying patterns of expression, necrosis-inducing activity, and positive selection suggest that NLP have diversified in function.

  9. Phytophthora infestans RXLR Effector PexRD2 Interacts with Host MAPKKKε to Suppress Plant Immune Signaling[W][OPEN

    Science.gov (United States)

    King, Stuart R.F.; McLellan, Hazel; Boevink, Petra C.; Armstrong, Miles R.; Bukharova, Tatyana; Sukarta, Octavina; Win, Joe; Kamoun, Sophien; Birch, Paul R.J.; Banfield, Mark J.

    2014-01-01

    Mitogen-activated protein kinase cascades are key players in plant immune signaling pathways, transducing the perception of invading pathogens into effective defense responses. Plant pathogenic oomycetes, such as the Irish potato famine pathogen Phytophthora infestans, deliver RXLR effector proteins to plant cells to modulate host immune signaling and promote colonization. Our understanding of the molecular mechanisms by which these effectors act in plant cells is limited. Here, we report that the P. infestans RXLR effector PexRD2 interacts with the kinase domain of MAPKKKε, a positive regulator of cell death associated with plant immunity. Expression of PexRD2 or silencing MAPKKKε in Nicotiana benthamiana enhances susceptibility to P. infestans. We show that PexRD2 perturbs signaling pathways triggered by or dependent on MAPKKKε. By contrast, homologs of PexRD2 from P. infestans had reduced or no interaction with MAPKKKε and did not promote disease susceptibility. Structure-led mutagenesis identified PexRD2 variants that do not interact with MAPKKKε and fail to support enhanced pathogen growth or perturb MAPKKKε signaling pathways. Our findings provide evidence that P. infestans RXLR effector PexRD2 has evolved to interact with a specific host MAPKKK to perturb plant immunity–related signaling. PMID:24632534

  10. Karakterisering van de zuurgevoeligheid van Salmonella typhimurium faagtype DT104

    NARCIS (Netherlands)

    de Jonge R; van Leusden FM; Dufrenne JB; Ritmeester WS; Delfgou-van Asch EHM; van Pelt W; LBG

    1999-01-01

    Het aantal gevallen van salmonellosis in Nederland veroorzaakt door Salmonella typhimurium faagtype DT104 is toegenomen van 10 in 1985 tot 163 in 1997 (10% van alle gevallen van salmonellosis). De stam lijkt zijn oorsprong te hebben in het Verenigd Koninkrijk. Daar wordt inmiddels 20% van alle gev

  11. Fracturen van het distale deel van het femur

    NARCIS (Netherlands)

    Duyn, Cornelius Diederikus van

    1977-01-01

    ln dit proefschrift wordt een analyse gegeven van de behandeling en de daarmee bereikte resultaten van 123 patiënten die in de periode 1 januari 1958 tot en met 31 december 1972 wegens een fractuur van het distale deel van het femur werden behandeld in de Kliniek voor Heelkunde van het Academisch

  12. Factoren die van invloed zijn op enkele vruchtbaarheidskenmerken van zeugen.

    NARCIS (Netherlands)

    Klaver, J.; den Hartog, L.A.

    1989-01-01

    Gegevens van meerdere worpen van 358 zeugen Groot Yorkshire en Nederlands Landras zijn gebruikt om verbanden tussen produktiekenmerken te berekenen. Ingegaan wordt op de invloed van het voerniveau tijdens de zoogperiode en tijdens het interval van spenen tot dekken op diverse variabelen, die van bel

  13. Expats helpen elkaar : Analyse van participatie websites van expats

    NARCIS (Netherlands)

    Grimmelikhuijsen, S.G.; Werner, G.D.A.; Meijer, A.J.; Brandsma, G.J.

    2009-01-01

    Deze rapportage is het resultaat van het eerste onderdeel van het onderzoek van de USBO (Universiteit Utrecht) naar e-participatie van expats. In dit deelonderzoek is het aanbod van e-participatie initiatieven in kaart gebracht. In totaal zijn 139 websites geanalyseerd en beoordeeld op diverse crite

  14. Sequence Analysis of the Ribosomal DNA ITS of Phytophthora Parasitica in Tobacco in Liangshan Region of Sichuan Province%四川凉山地区烟草黑胫病菌的ITS序列分析

    Institute of Scientific and Technical Information of China (English)

    张海珊; 王勇; 许大凤; 刘东阳; 周本国; 高正良; 卢军; 章东方; 严丹侃; 王芳

    2015-01-01

    The internal transcribed spacer regions (ITS) of the ribosomal RNA gene from 20 isolates of tobacco black shank were amplified with the polymerase chain reaction through the universal primers and sequence. The result showed that the total length of ITS of those 20 isolates tested were all 803bp, and the nucleotide sequence identity among those sequences was above 99.3%, and 20 strains had 99.6%-100%homologies with Phytophthora parasitica(GU111675.1) published in GenBank. But the ITS of those 20 isolates tested had some mutation sites which mainly concentrated in the ITS2 area and 468 mutation of isolates, which mainly came from Dechang and Xichang had certain regional. With the bio-software of MEGA6, Sequences from the above isolates were compared with 15 sequences published in GenBank database and phylogenitic trees were constructed based on ITS sequence data. The results showed that the isolates tested, GU111675.1, KF010303.1, AJ854295.1, KC768775.1 and L41383 were clustered into the same clade and all were Phytophthora parasitica (or Phytophthora nicotianae). They were clustered in a distant clade for different Phytophthora species and phylogenetically distinct each other. The results indicated that twenty isolates which isolated from different regions of Liangshan prefecture were Phytophthora parasitica.%本研究利用真菌核糖体基因转录间隔区(ITS)通用引物,PCR 扩增四川省凉山州不同地区的20株烟草黑胫病菌的ITS序列,并对PCR产物进行了克隆测序。结果表明,20个供试菌株的ITS1-5.8S-ITS2总长均为803 bp;各菌株之间的ITS序列同源性达到99.3%以上;与GenBank报道的寄生疫霉台湾烟草分离株Phytophthora parasitica(GU111675.1)的同源性在99.6%~100%之间;但各菌株ITS序列的个别位点存在突变,这些突变主要集中在ITS2区上,其中第468处的突变具有一定地域性,主要为德昌和西昌的菌株。利用MEGA6软件对20个

  15. A molecular method to assess Phytophthora diversity in environmental samples.

    Science.gov (United States)

    Scibetta, Silvia; Schena, Leonardo; Chimento, Antonio; Cacciola, Santa O; Cooke, David E L

    2012-03-01

    Current molecular detection methods for the genus Phytophthora are specific to a few key species rather than the whole genus and this is a recognized weakness of protocols for ecological studies and international plant health legislation. In the present study a molecular approach was developed to detect Phytophthora species in soil and water samples using novel sets of genus-specific primers designed against the internal transcribed spacer (ITS) regions. Two different rDNA primer sets were tested: one assay amplified a long product including the ITS1, 5.8S and ITS2 regions (LP) and the other a shorter product including the ITS1 only (SP). Both assays specifically amplified products from Phytophthora species without cross-reaction with the related Pythium s. lato, however the SP assay proved the more sensitive and reliable. The method was validated using woodland soil and stream water from Invergowrie, Scotland. On-site use of a knapsack sprayer and in-line water filters proved more rapid and effective than centrifugation at sampling Phytophthora propagules. A total of 15 different Phytophthora phylotypes were identified which clustered within the reported ITS-clades 1, 2, 3, 6, 7 and 8. The range and type of the sequences detected varied from sample to sample and up to three and five different Phytophthora phylotypes were detected within a single sample of soil or water, respectively. The most frequently detected sequences were related to members of ITS-clade 6 (i.e. P. gonapodyides-like). The new method proved very effective at discriminating multiple species in a given sample and can also detect as yet unknown species. The reported primers and methods will prove valuable for ecological studies, biosecurity and commercial plant, soil or water (e.g. irrigation water) testing as well as the wider metagenomic sampling of this fascinating component of microbial pathogen diversity.

  16. Die etiek van Luther

    Directory of Open Access Journals (Sweden)

    J. H. van Wyk

    1983-06-01

    Full Text Available Dink ons aan die etiek van Luther dan spring onmiddellik ’n paar boeiende uitsprake van hom na vore soos o.a. dat Christene vanuit die gemeenskap met Christus nuwe dekaloë moet maak wat helderder as die van Moses kan wees, of dat ons in bepaalde sin vir ons naaste ’n Christus moet word. Die bydrae van Luther 'tot die Christelike etiek is sonder twyfel van groot betekenis en die bestudering daarvan die moeite werd. Luther is geprys as rewolusionêr en verguis as konserwatis, hy is geëer as iemand wat weer die ware be­tekenis van godsdiens ontdek het toe die lewe vervloei het in etiek. Of dit egter korrek is om sy etiek as konserwatief te tipeer, soos White doen, moet betwyfel word.

  17. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici.

    Science.gov (United States)

    Sang, Mee Kyung; Shrestha, Anupama; Kim, Du-Yeon; Park, Kyungseok; Pak, Chun Ho; Kim, Ki Deok

    2013-06-01

    We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

  18. Uitspoeling van zware metalen uit landbouwgronden; schatting van de bijdrage van uitspoeling uit landbouwgronden aan de belasting van het oppervlaktewater

    NARCIS (Netherlands)

    Römkens, P.F.A.M.; Groenenberg, J.E.; Bril, J.; Vries, de W.

    2002-01-01

    Uitspoeling van metalen vanuit de bodem naar grond- en oppervlaktewater is tot nu toe niet meegenomen bij de schattingen van de belasting van oppervlaktewater met metalen. Om te kunnen beoordelen of de bijdrage van uitspoeling wezenlijk bijdraagt aan de belasting van oppervlaktewater is een model on

  19. De auteursrechtelijke groeipijnen van Google

    NARCIS (Netherlands)

    Hugenholtz, P.B.

    2011-01-01

    Het succesverhaal van Google behoort tot de canon van de geschiedenis van onze informatiemaatschappij. In 1998 begonnen in een studentenkamer op de campus van Stanford University, groeide Google in enkele jaren uit tot het orakel van het internet. Zo werd ‘googelen’ de gebruikelijke term voor zoeken

  20. Teelt van knolvenkel

    NARCIS (Netherlands)

    Buishand, T.; Jonge, de P.

    1984-01-01

    Herziene teelthandleiding over plantkundige eigenschappen, grond, bemesting, ervaringen met rassen in Nederland, zaaien en planten, onkruidbestrijding, ziekten en plagen, oogst, bewaring, aflevering, voorbeelden van arbeidsbehoefte en saldoberekeningen

  1. Transformation of the oomycete pathogen, Phytophthora infestans.

    Science.gov (United States)

    Judelson, H S; Tyler, B M; Michelmore, R W

    1991-01-01

    A stable transformation procedure has been developed for Phytophthora infestans, an oomycete fungus that causes the late blight diseases of potato and tomato. This is the first description of reliable methods for transformation in an oomycete pathogen. Drug-resistant transformants were obtained by using vectors that contained bacterial genes for resistance to hygromycin B or G418 fused to promoters and terminators from the Hsp70 and Ham34 genes of the oomycete, Bremia lactucae. Using polyethylene glycol and CaCl2, vector DNA was introduced into protoplasts as a complex with cationic liposomes or with carrier DNA only. Transformants were obtained at similar frequencies with each combination of promoter and selectable marker and were confirmed by DNA and RNA hybridization and phosphotransferase assays. Transformation occurred through the integration of single or tandemly repeated copies of the plasmids into genomic DNA, conferring mitotically stable drug-resistant phenotypes. The sizes of the marker gene mRNAs in each transformant and the results of transcript mapping studies were consistent with the function of the B. lactucae regulatory sequences in P. infestans. A hygromycin-resistant transformant was tested and found to maintain pathogenicity, indicating that the gene transfer procedure will be useful for the molecular analysis of genes relevant to disease.

  2. Phytophthora infestans population structure: a worldwide scale

    Directory of Open Access Journals (Sweden)

    Cárdenas Toquica Martha

    2012-08-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep (Peptidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and the mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America expanding on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  3. PHYTOPHTHORA INFESTANS POPULATION STRUCTURE: A WORLDWIDE SCALE

    Directory of Open Access Journals (Sweden)

    MARTHA CÁRDENAS

    2012-01-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of the pathogen’s population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep (Peptidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America, expanding it on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  4. Survival of Phytophthora infestans in Surface Water.

    Science.gov (United States)

    Porter, Lyndon D; Johnson, Dennis A

    2004-04-01

    ABSTRACT Coverless petri dishes with water suspensions of sporangia and zoospores of Phytophthora infestans were embedded in sandy soil in eastern Washington in July and October 2001 and July 2002 to quantify longevity of spores in water under natural conditions. Effects of solar radiation intensity, presence of soil in petri dishes (15 g per dish), and a 2-h chill period on survival of isolates of clonal lineages US-8 and US-11 were investigated. Spores in water suspensions survived 0 to 16 days under nonshaded conditions and 2 to 20 days under shaded conditions. Mean spore survival significantly increased from 1.7 to 5.8 days when soil was added to the water. Maximum survival time of spores in water without soil exposed to direct sunlight was 2 to 3 days in July and 6 to 8 days in October. Mean duration of survival did not differ significantly between chilled and nonchilled sporangia, but significantly fewer chilled spores survived for extended periods than that of nonchilled spores. Spores of US-11 and US-8 isolates did not differ in mean duration of survival, but significantly greater numbers of sporangia of US-8 survived than did sporangia of US-11 in one of three trials.

  5. Invoering van algemene vaardigheden: mogelijkheden van een vakoverstijgende aanpak

    NARCIS (Netherlands)

    Leenders, F.J.

    2003-01-01

    Centrale vraag: Het onderzoek richtte zich op de implementatie van vakoverstijgend vaardighedenonderwijs in de Tweede Fase van het voortgezet onderwijs. Belangrijkste conclusies: De brochure bevat onder meer een beschrijving van vijf scholen waar op verschillende wijze vaardighedenonderwijs

  6. Ontwikkeling van de beverpopulaties in Nederland van 2000-2004

    NARCIS (Netherlands)

    Niewold, F.J.J.

    2004-01-01

    Dit rapport beschrijft de aantalsontwikkeling van de beverpopulaties in Nederland in de periode 2000-2004. Van twee populaties (Gelderse Poort en Flevoland) werden, mede met hulp van vrijwilligers, ook gegevens verzameld over voortplanting, sterfte, dispersie, bijplaatsingen, verstoringen, vraatscha

  7. Het beoordelen van de klinische competenties van studenten tandheelkunde

    NARCIS (Netherlands)

    Schoonheim-Klein, M.E.; van Selms, M.K.A.; Volgenant, C.M.C.; Wiegman, H.P.; Vervoorn, J.M.

    2012-01-01

    Studenten tandheelkunde worden tegenwoordig meer beoordeeld op de kwaliteit van hun verrichtingen (competentie) en minder op de kwantiteit. Om klinische competenties van studenten te toetsen kunnen in de preklinische fase van de opleiding objectieve gestructureerde toetsen, de zogeheten‘ bjective st

  8. Normering van meetnauwkeurigheden van klimaatmetingen in praktijkkassen : [eindrapport

    NARCIS (Netherlands)

    Berg, van den G.A.; Ruiter, de H.W.

    1998-01-01

    In het project 'Normering van meetnauwkeurigheden van klimaatmetingen in praktijkkassen' zijn eisen opgesteld waaraan meetsystemen voor de kasklimaatregeling in praktijkkassen, zowel uit technisch als uit teelttechnisch oogpunt, zouden moeten voldoen. Op basis van de geformuleerde eisen, is vervolge

  9. Normering van meetnauwkeurigheden van klimaatmetingen in praktijkkassen : [eindrapport

    NARCIS (Netherlands)

    Berg, van den G.A.; Ruiter, de H.W.

    1998-01-01

    In het project 'Normering van meetnauwkeurigheden van klimaatmetingen in praktijkkassen' zijn eisen opgesteld waaraan meetsystemen voor de kasklimaatregeling in praktijkkassen, zowel uit technisch als uit teelttechnisch oogpunt, zouden moeten voldoen. Op basis van de geformuleerde eisen, is vervolge

  10. Overzicht van de kostprijzen van enige tuinbouwproducten (prijspeil 1947)

    NARCIS (Netherlands)

    Koppert, C.

    1948-01-01

    In dit rapport wordt een overzicht gegeven van de kostprijsberekeningen van de voornaamste tuinbouwproducten, welke ontleend zijn aan de rapporten, die in 1947 door de Afd. Tuinbouw van het Landbouw-Economisch Instituut zijn uitgebracht.

  11. Karakterisering van het Etimologiewoordeboek van Afrikaans (EWA

    Directory of Open Access Journals (Sweden)

    Fons Moerdijk

    2011-10-01

    Full Text Available

    Samenvatting: Zesendertig jaar na Afrikaanse etimologieë van Boshoff en Nienaber verscheener in 2003 een nieuw etymologisch woordenboek van het Afrikaans: het Etimologiewoordeboek vanAfrikaans (EWA. Tussen die twee woordenboeken bestaat een wezenlijk verschil. Het werk vanBoshoff en Nienaber is vrijwel alleen toegankelijk voor specialisten en niet specifiek bedoeld vooreen breed publiek. EWA is juist allereerst bestemd voor de leek die zich interesseert voor de oorsprongen de geschiedenis van de eigen taal. Daarnaast biedt het ook de etymoloog en historischtaalkundige een hoop gegevens en inspiratie voor nader onderzoek. Als etymologisch woordenboekbezit EWA een aantal bijzondere, eigen kenmerken. De selectie van de woorden is bepaalddoor het beoogde gebruikerspubliek. Als gevolg daarvan bevat EWA verscheidene typen woordendie in traditionele etymologische woordenboeken doorgaans veronachtzaamd worden, zoals afleidingen,samenstellingen, neologismen en gemeenzame spreektaalwoorden. De artikelstructuurwordt gekenmerkt door een hoge graad van uniformiteit en consistentie. Het accent ligt op dezogenaamde etymologia proxima, de etymologie waarbij men één stap teruggaat en de meestdirecte herkomst van het woord biedt. Voorts is speciale aandacht besteed aan polysemie: nietalleen de herkomst van de dominante betekenis van een woord wordt gegeven, maar ook die vanzijn eventuele andere betekenis(sen. Benoemingsmotieven komen ook veelvuldig aan bod. In eeneventuele tweede druk zouden opvallende verschillen in vorm of betekenis altijd verklaard of inieder geval besproken moeten worden. Dat blijft nu nogal eens achterwege. Ook zou voorafgaandaan zo'n volgende editie meer onderzoek naar woordhistorisch materiaal uit primaire bronnenvoor met name de 17de–19de eeuw verricht moeten worden. Het zou mooi zijn als deze eersteuitgave van EWA de aanleiding tot een dergelijk onderzoek zou vormen.

    Sleutelwoorden: BENOEMINGSMOTIEF, ETYMOLOGIA PROXIMA

  12. Ontwikkeling van een vloeistofchromatografische methode voor de bepaling van residuen van meticlorpindol in pluimveevlees

    NARCIS (Netherlands)

    Beek, W.M.J.; Keukens, H.J.

    1994-01-01

    In dit rapport wordt de ontwikkeling van een methode beschreven voor de bepaling van residuen van meticlorpindol in pluimveevlees met behulp van HPLC en UV-detectie. Er is onderzoek verricht naar de chromatografische scheiding van meticlorpindol op reversed phase kolommen, naar een geschikte extract

  13. Het Geluid van Nederland. De rol van communicatie bij het crowdsourcen van geluid bij online gemeenschappen

    NARCIS (Netherlands)

    A. van der Meulen (Anna)

    2014-01-01

    textabstractHet doel van dit onderzoek is om aanbevelingen te doen op het gebied van communicatie aan de afdeling Research & Development van het Nederlands Instituut voor Beeld en Geluid over de rol van crowdsourcing en online gemeenschappen bij het aanvullen, openstellen en up-to-date houden van he

  14. Ontwikkeling van een vloeistofchromatografische methode voor de bepaling van residuen van meticlorpindol in pluimveevlees

    NARCIS (Netherlands)

    Beek, W.M.J.; Keukens, H.J.

    1994-01-01

    In dit rapport wordt de ontwikkeling van een methode beschreven voor de bepaling van residuen van meticlorpindol in pluimveevlees met behulp van HPLC en UV-detectie. Er is onderzoek verricht naar de chromatografische scheiding van meticlorpindol op reversed phase kolommen, naar een geschikte extract

  15. Onderzaai van klaver in peen

    NARCIS (Netherlands)

    Schelling, G.; Theunissen, J.

    2000-01-01

    In vier achtereenvolgende jaren (1995 - 1998) is door Plant Research International een proef gedaan met onderzaai van ondergrondse klaver (Trifolium subterraneum) in een vlakveldse teelt van wortelen. De effecten van onderzaai op percentage marktbare wortelen, aantasting door wortelvlieg (Psila rosa

  16. Pherobank: gecontroleerde afgifte van lokstoffen

    NARCIS (Netherlands)

    Stol, W.; Griepink, F.C.

    2007-01-01

    Achtergrond. Synthetische signaalstoffen (feromonen) worden wereldwijd toegepast voor de signalering en bestrijding van plaaginsecten in geïntegreerde bestrijdingsmethoden (Integrated Pest Management). Door de omschakeling van primaire producenten van de gangbare naar geïntegreerde- en biologische p

  17. Cytotoxiciteitsanalyse van glans/ontspanningsmiddelen

    NARCIS (Netherlands)

    Geffen MF van; Orzechowski TJH; Machielsen JCA; Asten JAAM van; LGM

    1994-01-01

    Twee cytotoxiciteitstesten, gevalideerd voor de bepaling van de biocompatibiliteit van medische hulpmiddel extracten, zijn toegepast op glans/ontspanningsmiddelen. Glans/ontspanningsmiddelen ("instrumenten-melk") worden gebruikt bij de laatste processtap voor het reinigen van chirurgis

  18. Dialyse van citraatbloed voor transfusie

    NARCIS (Netherlands)

    Huizinga, Tekke

    1957-01-01

    Na 1943 is een aantal publikaties verschenen, waarin melding wordt gemaakt van citraatintoxicaties tengevolge van snelle transfusies van grote hoeveelheden citraatbloed. Deze publikaties zijn uitganspunt geweest voor een aantal dierproeven, waarin de klinische ervaringen experimenteel werden

  19. Voorkom insleep van ziekten

    NARCIS (Netherlands)

    Groenen, J.A.J.Th.

    1990-01-01

    De insleep en verspreiding van ziektekiemen kan een pluimveebedrijf grote schade opleveren. Er dient dan ook alles aan gedaan te worden om dit te voorkomen. Een goede hygiëne is daarbij een eerste vereiste. Daartoe behoort ook de grondige reiniging enontsmetting van een stal nadat een koppel dieren

  20. Economie van energiegewassen

    NARCIS (Netherlands)

    Voort, van der M.P.J.

    2008-01-01

    Bio-energie staat sterk in de belangstelling. De wens naar een meer duurzame energievoorziening is hierbij een belangrijke drijfveer. Ook vanuit de akkerbouw is er interesse in het telen van gewassen voor de productie van energie. Belangrijke vraag bij de afweging om energiegewassen te gaan telen, i

  1. Praktijkevaluatie van 'piglet snatching'

    NARCIS (Netherlands)

    Smits, J.M.; Binnendijk, G.P.; Eijck, I.A.J.M.

    2002-01-01

    Bij piglet snatching worden biggen van een zeug direct bij de geboorte weggevangen en overgelegd naar een zeug op een ander bedrijf. In de praktijk is dit een goede, welzijnsvriendelijke manier om biggen van een bedrijf met een lage ziektevrij-status maar met een hoge genetische waarde over te breng

  2. Erosie van rivieroevers

    NARCIS (Netherlands)

    Mosselman, E.

    1987-01-01

    Oevers staan sinds kart in het middelpunt van de belangstellingbij beheerders van oppervlaktewateren in Nederland. Niet langerbeschouwt men oevers slechts als randverschijnsel, maar alsobjecten met een duidelijk eigen plaats en functie.Het streven om te komen tot een integraal waterbeleid

  3. Jaap van Praag

    NARCIS (Netherlands)

    Gasenbeek, A.

    2007-01-01

    PRAAG, JAAP VAN (1911-1981), Dutch organizer and theoretician of organized HUMANISM. Jaap van Praag was born on May 11, 1911, in Amsterdam. He grew up in a secular Jewish and socialist family. Mainly through his mother and by much reading he acquired considerable knowledge of the Bible. He studied D

  4. Dialectiek van de verlichting

    NARCIS (Netherlands)

    Hoogland, Jan

    2006-01-01

    Vooral door het boek Dialektik der Aufklärung van Horkheimer en Adorno heeft het bewustzijn zich doorgezet dat een ten opzichte van zichzelf onkritische verlichting haar eigen tegenkrachten oproept. In deze bijdrage wordt op dit fenomeen nader ingegaan, in het bijzonder met het oog op een dogmatisch

  5. Kroniek van het mededingingsrecht

    NARCIS (Netherlands)

    Wesseling, R.; Truijens Martinez, J.

    2015-01-01

    Waar liggen de grenzen van het bereik van het mededingingsrecht? Die vraag komt steeds vaker op. Buiten het mededingingsrecht heeft de Europese Commissie beperkte handhavingsbevoegdheden. Voor de Commissie is een probleem dus al snel een mededingingsrechtelijke kwestie. De Libor-affaire en

  6. Keuzeprocessen van Consumenten

    NARCIS (Netherlands)

    B. Wierenga (Berend)

    1987-01-01

    textabstractVoor de aanbieder van een voedingsmiddel, of dit nu een merkprodukt a la Mona is of een 'commodity', bijvoorbeeld karnemelk, is het van groot belang te weten welke factoren bepalen of een consument het betreffende produkt zal kiezen dan wel voor een concurrerend alternatief zal opteren.

  7. De teelt van walnoten

    NARCIS (Netherlands)

    Wertheim, S.J.

    1981-01-01

    De laatste jaren is er weer een toenemende belangstelling voor walnoten te constateren. Deze interesse komt in een enkel geval van een grondeigenaar die met noteteelt zijn grond rendabel wil maken. Meestal gaat het echter om de beplanting van erven, overhoeken, wegbermen en dijken. Vanwege deze bela

  8. Van buitenaf - Innovatie

    NARCIS (Netherlands)

    Mol, Erik; Heus, Ronald; Visser, Thomas

    2008-01-01

    Het optreden van de brandweer moet meeveranderen met snelle ontwikkelingen in de maatschappij en de mogelijkheden van de informatie- en communicatietechnologie (ICT). Dat stellen onderzoekers Eric Mol, Ronald Heus en Thomas Visser. Zij zijn verbonden aan TNO Defensie en Veiligheid en het First Respo

  9. Leefbaarheid van landen

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    1996-01-01

    textabstractSAMENVATTING Leefbaarheid van landen wordt meestal beoordeeld aan het aanbod van zaken waarvan men denkt dat ze goed zijn voor mensen, zoals welvaart, werkgelegenheid, opleiding en gezondheidszorg. Dat aanbod wordt dan gemeten met puntenstelsels. Een voorbeeld daarvan is de Human Develop

  10. Weidegang van geiten

    NARCIS (Netherlands)

    Eekeren, van N.J.M.

    2011-01-01

    Weidegang is belangrijk voor het welzijn van geiten. Daarmee is het een essentieel onderdeel van de bedrijfsvoering en bovendien onderscheidend voor de biologische geitenhouderij. Helaas levert weidegang bij geiten ook een aantal knelpunten op zoals: het risico op een maagdarmwormenbesmetting, ruimt

  11. Grondbeginselen van de methode

    NARCIS (Netherlands)

    Pestalozzi, Johann Heinrich

    1995-01-01

    In opvoeding en onderwijs gaat het volgens Pestalozzi om de ontwikkeling van hoofd, hart en handen (‘Pädagogik des Kopfes, des Herzens und der Hand’). Het beste geschiedt dat door middel van de ‘natuurlijke opvoeding’. Hij noemde dit zijn ‘methode’.

  12. Sociale vergelijking van salarissen.

    NARCIS (Netherlands)

    Grumbkow, Jasper von

    1980-01-01

    Het onderwerp van het onderzoeksverslag is de nieuwsgierigheid van mensen naar salarisgegevens. Centraal in deze studie staat de sociale vergelijkingstheorie (Festinger, 1954) op grond waarvan aangenomen wordt dat mensen twee doelen op het oog hebben wanneer ze hun aandacht richten op salarisgegeven

  13. Kroniek van het mededingingsrecht

    NARCIS (Netherlands)

    Wesseling, R.; Truijens Martinez, J.

    2015-01-01

    Waar liggen de grenzen van het bereik van het mededingingsrecht? Die vraag komt steeds vaker op. Buiten het mededingingsrecht heeft de Europese Commissie beperkte handhavingsbevoegdheden. Voor de Commissie is een probleem dus al snel een mededingingsrechtelijke kwestie. De Libor-affaire en vergelijk

  14. The Effect of Potassium Nitrate on the Reduction of Phytophthora Stem Rot Disease of Soybeans, the Growth Rate and Zoospore Release of Phytophthora Sojae

    Science.gov (United States)

    The effects of potassium nitrate (KNO3) application on Phytophthora stem rot disease reduction of Glycine max (L.) Merr. cvs. Chusei-Hikarikuro and Sachiyutaka, and fungal growth and zoospore release of a Phytophthora sojae isolate were investigated under laboratory conditions. The application of 4-...

  15. Detection, diversity, and population dynamics of waterborne Phytophthora ramorum populations

    Science.gov (United States)

    Catherine Eyre; Matteo Garbelotto

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed...

  16. Validation of a tuber blight (Phytophthora infestans) prediction model

    Science.gov (United States)

    Potato tuber blight caused by Phytophthora infestans accounts for significant losses in storage. There is limited published quantitative data on predicting tuber blight. We validated a tuber blight prediction model developed in New York with cultivars Allegany, NY 101, and Katahdin using independent...

  17. Interaction between the moss Physcomitrella patens and Phytophthora

    NARCIS (Netherlands)

    Overdijk, Elysa J.R.; Keijzer, De Jeroen; Groot, De Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

    2016-01-01

    Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for v

  18. Potato late blight epidemics and population structure of Phytophthora infestans.

    NARCIS (Netherlands)

    Zwankhuizen, M.J.

    1998-01-01

    Potato late blight is caused by the fungus Phytophthora infestans . To study the relative importance of oospores in the epidemiology, and to estimate the relative impact of various infection sources, late blight epidemics in Southern Flevoland (The Netherlands) were studied using epidemiological and

  19. Susceptibility of highbush blueberry cultivars to Phytophthora root rot

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  20. Interactions between biosurfactant-producing Pseudomonas and Phytophthora species

    NARCIS (Netherlands)

    Tran, H.

    2007-01-01

    Fluorescent Pseudomonas bacteria produce a wide variety of antimicrobial metabolites, including soap-like compounds referred to as biosurfactants. The results of this thesis showed that biosurfactant-producing Pseudomonas bacteria are effective in controlling Phytophthora foot rot disease of black p

  1. Correlating Phytophthora ramorum infection rate and lesion expansion in tanoak

    Science.gov (United States)

    Katherine Hayden; Heather Rickard; Matteo Garbelotto

    2008-01-01

    To date, resistance to Phytophthora ramorum in its most susceptible hosts has most commonly been quantified by lesion growth, after wounding or non-wounding inoculations via mycelia or high concentrations of zoospores. However, even highly susceptible hosts may not always become infected when they are exposed to a pathogen under ecologically...

  2. Phytophthora ramorum and P. kernoviae: regulation in the European union

    Science.gov (United States)

    Stephen Hunter

    2008-01-01

    The history of the regulation of action against Phytophthora ramorum and P. kernoviae in the EU and U.K. is briefly summarised. For the former there are EU controls on the import of host plants, and the internal regime of plant passporting has been extended to cover Rhododendron, Viburnum and...

  3. Stable transformation of the oomycete, Phytophthora infestans, using microprojectile bombardment

    DEFF Research Database (Denmark)

    Cvitanich, Cristina; Judelson, Howard S.

    2003-01-01

    Germinated asexual sporangia, zoospores, and mycelia of Phytophthora infestans were transformed to G418-resistance by microprojectile bombardment. After optimization, an average of 14 transformants/shot were obtained, using 10(6) germinated sporangia and gold particles coated with 1 microg...

  4. A Surface Plasmon Resonance Immunobiosensor for Detection of Phytophthora infestans

    DEFF Research Database (Denmark)

    Skottrup, Peter; Frøkiær, Hanne; Hejgaard, Jørn;

    In this study we focused on the development of a Surface Plasmon Resonance (SPR) immunosensor for Phytophthora infestans detection. The fungus-like organism is the cause of potato late blight and is a major problem in potato growing regions of the world. Efficient control is dependent on early...

  5. Carbohydrate-related enzymes of important Phytophthora plant pathogens.

    Science.gov (United States)

    Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P

    2014-11-01

    Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZymes present in the Phytophthora infestans, Ph. ramorum, Ph. sojae and Pythium ultimum genomes compared to growth of these species on a range of different carbon sources. Growth on these carbon sources indicates that the size of enzyme families involved in degradation of cell-wall related substrates like cellulose, xylan and pectin is not always a good predictor of growth on these substrates. While a capacity to degrade xylan and cellulose exists the products are not fully saccharified and used as a carbon source. The Phytophthora genomes encode larger CAZyme sets when compared to Py. ultimum, and encode putative cutinases, GH12 xyloglucanases and GH10 xylanases that are missing in the Py. ultimum genome. Phytophthora spp. also encode a larger number of enzyme families and genes involved in pectin degradation. No loss or gain of complete enzyme families was found between the Phytophthora genomes, but there are some marked differences in the size of some enzyme families.

  6. Phytophthora ramorum causes cryptic bole cankers in Canyon line Oak

    Science.gov (United States)

    Unusual mortality of large canyon live oaks was observed in natural stands in San Mateo, California starting in 2007. A survey of affected stands showed that symptomatic trees were spatially associated with California bay, the primary source of Phytophthora ramorum spores in this forest type. Trunk ...

  7. Production, survival and infectivity of oospores of Phytophthora infestans

    NARCIS (Netherlands)

    Turkensteen, L.J.; Flier, W.G.; Mulder, A.; Wanningen, R.

    2000-01-01

    The formation of oospores of Phytophthora infestans was studied in tomato and potato crops and volunteer plants under field conditions, and in laboratory tests with leaf discs of potato cultivars differing in their level of race-nonspecific resistance. Oospores were readily detected in

  8. The biology of Phytophthora infestans at its center of origin

    NARCIS (Netherlands)

    Grünwald, N.J.; Flier, W.G.

    2005-01-01

    The central highlands of Mexico are considered to be a center of genetic diversity for both the potato late blight pathogen and for tuber-bearing Solanum spp. Recent work conducted in Mexico and South America sheds new light on the biology and evolution of Phytophthora infestans and other related Ph

  9. Histology of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues

    Science.gov (United States)

    Molly Botts Giesbrecht; Everett M. Hansen; Peter Kitin

    2011-01-01

    Colonisation of Notholithocarpus densiflorus (Hook. and Arn.) Rehder tissues by Phytophthora ramorum Werres, De Cock & Man in't Veld is not well understood. The pathogen is able to colonise nearly all tissues of this host but it is unclear how a tree is ultimately killed. In this research,

  10. Resistance to Phytophthora cinnamomi in the Genus Abies

    Science.gov (United States)

    John Frampton; Fikret Isik; Mike Benson; Jaroslav Kobliha; Jan Stjskal

    2012-01-01

    A major limiting factor for the culture of true firs as Christmas trees is their susceptibility to Oomycete species belonging to the genus Phytophthora. In North Carolina alone, the Fraser fir (Abies fraseri [Pursh] Poir.) Christmas tree industry loses 6 to 7 million dollars annually to root rot primarily caused by ...

  11. The maturation and germination of Phytophthora ramorum Chlamydospores

    Science.gov (United States)

    Aaron L. Smith; Everett M. Hansen

    2008-01-01

    Chlamydospores are a distinctive feature of Phytophthora ramorum. They are formed quickly in agar, and within colonized leaves. We followed their development and maturation in vitro and in vivo, and studied conditions affecting their germination. Cell walls of mature P. ramorum chlamydospores...

  12. Can Phytophthora ramorum be spread with contaminated irrigation water?

    Science.gov (United States)

    D. Seipp; T. Brand; K. Kaminski; S. Wagner; S. Werres

    2008-01-01

    In a two year study, the spread of Phytophthora ramorum with contaminated irrigation water and the survival of the pathogen in water reservoirs were studied (Werres and others 2007). In addition at the end of each experimental period root ball samples from asymptomatic plants were taken to look for contamination with P. ramorum....

  13. Can Epiphytes reduce disease symptoms caused by Phytophthora ramorum

    Science.gov (United States)

    Leaf infection of ornamental species by Phytophthora ramorum has a significant impact on the spread of this disease. Fungicides have had limited effects on controlling this disease. With increasing concerns that repeated fungicide applications will exasperate the potential for fungicide resistance...

  14. Multi-scale modelling of infection pressure from Phytophthora infestans

    NARCIS (Netherlands)

    Skelsey, P.; Werf, van der W.; Kessel, G.J.T.; Rossing, W.A.H.; Holtslag, A.A.M.

    2007-01-01

    Management of potato late blight could benefit from prediction of the risk posed to potato fields from external inoculum sources of Phytophthora infestans. Influx of inoculum depends on a complex interplay of population biological, atmospheric and spore survival processes, and is difficult to predic

  15. Proeven van tekstkritiek. Een onderzoek betreffende de tekstgeschiedenis van de Renout van Montalbaen en de Perceval

    NARCIS (Netherlands)

    Hogenhout-Mulder, Maaike Janna

    1984-01-01

    In dit proefschrift wordt een poging gedaan de tekstgeschiedenis te achterhalen van twee Middelnederlandse tekstfragmenten: een gedeelte uit de RENOUT VAN MONTALBAEN en een gedeelte uit de PERCEVAL. ... Zie: Twee tekstfragmenten als object van onderzoek

  16. Genome-wide identification of laccase gene family in three Phytophthora species.

    Science.gov (United States)

    Feng, Baozhen; Li, Peiqian

    2012-12-01

    Phytophthora spp. is a primary pathogen in oomycete, causing economically and environmentally devastating epidemics of plants. Laccases have been found in all domains of life but have not been reported in oomycte. In this paper, laccase genes of Phytophthora spp. were identified in three genomes (Phytophthora capsici, Phytophthora sojae and Phytophthora ramorum). 18 laccase genes were identified in total, including four in P. capsici genome, six in P. sojae genome and eight in P. ramorum genome. Most of the predicted gene models shared typical fungal laccase character, possessing three conserved positions with one cysteine and ten histidine residues at these positions. Phylogenetic analysis illustrated that laccases from Phytophthora clustered into four clades, while fungal laccases clustered together. The results provided the theoretical ground for new hypotheses about the roles laccases in oomycetes and may guide the future research of these enzymes.

  17. Two novel species representing a new clade and cluster of Phytophthora.

    Science.gov (United States)

    Yang, Xiao; Copes, Warren E; Hong, Chuanxue

    2014-01-01

    Phytophthora stricta sp. nov. and Phytophthora macilentosa sp. nov. are described based on morphological, physiological and molecular characters in this study. Phytophthora stricta represents a previously unknown clade in the rRNA internal transcribed spacer (ITS)-based phylogeny. Phytophthora macilentosa, along with nine other species, consistently forms a high temperature-tolerant cluster within ITS clade 9. These observations are supported by the sequence analysis of the mitochondrial cytochrome c oxidase 1 gene. Both species are heterothallic and all examined isolates are A1 mating type. Phytophthora stricta produces nonpapillate and slightly caducous sporangia. This species is named after its characteristic constrictions on sporangiophores. Phytophthora macilentosa produces nonpapillate and noncaducous sporangia, which are mostly elongated obpyriform with a high length to breadth ratio. Both species were recovered from irrigation water of an ornamental plant nursery in Mississippi, USA and P. stricta was also recovered from stream water in Virginia, USA.

  18. Spectrum van huidinfecties : Van schandvlek tot zorg

    NARCIS (Netherlands)

    Vries, de Henry

    2011-01-01

    Of het nu expats, massatoeristen of militairen op vredesmissie in Afghanistan betreffen, wij stellen ons bewust of onbewust bloot aan exotische ziekteverwekkers. De geschiedenis leert dat migratie de mens eigen is en de oorzaak is geweest van dodelijke epidemieën met talloze slachtoffers. Ook vandaa

  19. Groen van toen: van buitenplaats tot schooltuin

    NARCIS (Netherlands)

    Oldenburger-Ebbers, C.S.; Karssen, J.

    2012-01-01

    Grote technische ontwikkelingen en toenemende welvaart hebben in de loop der eeuwen de natuur dichter bij de mens gebracht. In deze tentoonstelling staat de gebruiker van het door de mens geschapen groen centraal. Rond drie thema’s: particulier groen, wandelen in openbaar groen en wonen in het groen

  20. Hogere verwachtingen van technologie dan van elkaar?

    NARCIS (Netherlands)

    Stijn Verhagen

    2012-01-01

    Boekbespeking van Sherrie Turkle, 2011, Alone Together: Why We Expect More from Technology and Less from Each Other. New York: Basic Books. Mails, sms’jes, instant messages, tweets, Skype, voicemails, Facebookberichten – via smartphones en andere apparaten zijn we vrijwel non-stop in contact met

  1. Groen van toen: van buitenplaats tot schooltuin

    NARCIS (Netherlands)

    Oldenburger-Ebbers, C.S.; Karssen, J.

    2012-01-01

    Grote technische ontwikkelingen en toenemende welvaart hebben in de loop der eeuwen de natuur dichter bij de mens gebracht. In deze tentoonstelling staat de gebruiker van het door de mens geschapen groen centraal. Rond drie thema’s: particulier groen, wandelen in openbaar groen en wonen in het groen

  2. Hogere verwachtingen van technologie dan van elkaar?

    NARCIS (Netherlands)

    Verhagen, Stijn

    2012-01-01

    Boekbespeking van Sherrie Turkle, 2011, Alone Together: Why We Expect More from Technology and Less from Each Other. New York: Basic Books. Mails, sms’jes, instant messages, tweets, Skype, voicemails, Facebookberichten – via smartphones en andere apparaten zijn we vrijwel non-stop in contact met vri

  3. Biological differences between the evolutionary lineages within Phytophthora ramorum and Phytophthora lateralis: Should the lineages be formally taxonomically designated?

    Science.gov (United States)

    Clive Brasier

    2017-01-01

    It is now generally accepted that the four evolutionary lineages of Phytophthora ramorum (informally designated NA1, NA2, EU1, and EU2) are relatively anciently divergent populations, recently introduced into Europe and North America from different, unknown geographic locations; that recombinants between them are genetically unstable and probably...

  4. Survival of Phytophthora alni, Phytophthora kernoviae, and Phytophthora ramorum in a simulated aquatic environment at different levels of pH.

    Science.gov (United States)

    Kong, Ping; Lea-Cox, John D; Moorman, Gary W; Hong, Chuanxue

    2012-07-01

    Phytophthora ramorum, Phytophthora alni, and Phytophthora kernoviae present significant threats to biosecurity. As zoosporic oomycetes, these plant pathogens may spread through natural waterways and irrigation systems. However, survival of these pathogens in aquatic systems in response to water quality is not well understood. In this study, we investigated their zoospore survival at pH 3-11 in a 10% Hoagland's solution over a 14-day period. The results showed that all three pathogens were most stable at pH 7, although the populations declined overnight irrespective of pH. Extended survival of these species depended on the tolerance of pH of their germinants. Germinants of P. alni ssp. alni and P. ramorum were more basic tolerant (pH 5-11), while those of P. kernoviae were more acidic tolerant (pH 3-9). These tolerant germinants formed compact hyphae or secondary sporangia to allow longer survival of these pathogens. Long-term survival at a broad pH range suggests that these pathogens, especially P. ramorum, are adapted to an aquatic environment and pose a threat to new production areas through water dispersal. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  5. Lichtdoorlatendheid van kasdekken onder verschillende omstsndigheden

    NARCIS (Netherlands)

    Bot, G.P.A.

    1984-01-01

    Aandacht voor lichtonderschepping; bewolkingsgraad; direkte straling; diffuse straling en gevolgen van veranderingen in kaskonstruktie of materiaaleigenschappen ten aanzien van de lichtdoorlatendheid. Bij vergelijking van de lichttransmissie van diverse kasdekken dient te worden uitgegaan van standa

  6. Afvangen van fosfaat uit bloembollensector met ijzerzand

    NARCIS (Netherlands)

    Chardon, W.J.; Groenenberg, J.E.; Jansen, S.; Buijert, A.; Talens, R.; Krol, A.F.

    2014-01-01

    In het oppervlaktewater van de Bollenstreek is de fosfaatconcentratie veel hoger dan de norm van de Europese Kaderrichtlijn Water. Met ijzerzand, een nevenproduct van drinkwaterproductie, kan fosfaat worden afgevangen. Het hoogheemraadschap van Rijnland heeft drie maatregelen op basis van ijzerzand

  7. Tijdreeksanalyse van de meetgegevens van het Landelijk Meetnet Regenwatersamenstelling

    NARCIS (Netherlands)

    Kempen GT; Buishand TA; Reijnders HFR; Frantzen AJ; van den Eshof AJ

    1986-01-01

    De tijdsafhankelijke variaties in de maandelijkse gemiddelde concentraties en deposities in de periode van 1978 t/m 1984 van stoffen in regenwater, verzameld in een meetnet van twaalf stations, zijn beschreven a.d.h. van een multipele regressie model. Vooral is aandacht besteed aan de

  8. Vliegende start : de eerste 'echte' onderwijsbaan van Lesley van Scherpenseel

    NARCIS (Netherlands)

    Snoek, Marco; Hallink, Hanneke; Scherpenseel, van Lesley

    2015-01-01

    Dit interview is het tweede in een serie van drie interviews en geeft een kijkje in de keuken van een startende leerkracht in een van de tekortvakken. We speken met Lesley van Scherpenseel, docent Natuurkunde en TOA op het Metis Montessori Lyceum

  9. A universal microarray detection method for identification of multiple Phytophthora spp. using padlock probes.

    Science.gov (United States)

    Sikora, Katarzyna; Verstappen, Els; Mendes, Odette; Schoen, Cor; Ristaino, Jean; Bonants, Peter

    2012-06-01

    The genus Phytophthora consists of many species that cause important diseases in ornamental, agronomic, and forest ecosystems worldwide. Molecular methods have been developed for detection and identification of one or several species of Phytophthora in single or multiplex reactions. In this article, we describe a padlock probe (PLP)-based multiplex method of detection and identification for many Phytophthora spp. simultaneously. A generic TaqMan polymerase chain reaction assay, which detects all known Phytophthora spp., is conducted first, followed by a species-specific PLP ligation. A 96-well-based microarray platform with colorimetric readout is used to detect and identify the different Phytophthora spp. PLPs are long oligonucleotides containing target complementary sequence regions at both their 5' and 3' ends which can be ligated on the target into a circular molecule. The ligation is point mutation specific; therefore, closely related sequences can be differentiated. This circular molecule can then be detected on a microarray. We developed 23 PLPs to economically important Phytophthora spp. based upon internal transcribed spacer-1 sequence differences between individual Phytophthora spp. Tests on genomic DNA of many Phytophthora isolates and DNA from environmental samples showed the specificity and utility of PLPs for Phytophthora diagnostics.

  10. SCR96, a small cysteine-rich secretory protein of Phytophthora cactorum, can trigger cell death in the Solanaceae and is important for pathogenicity and oxidative stress tolerance.

    Science.gov (United States)

    Chen, Xiao-Ren; Li, Yan-Peng; Li, Qi-Yuan; Xing, Yu-Ping; Liu, Bei-Bei; Tong, Yun-Hui; Xu, Jing-You

    2016-05-01

    Peptides and small molecules produced by both the plant pathogen Phytophthora and host plants in the apoplastic space mediate the relationship between the interplaying organisms. Various Phytophthora apoplastic effectors, including small cysteine-rich (SCR) secretory proteins, have been identified, but their roles during interaction remain to be determined. Here, we identified an SCR effector encoded by scr96, one of three novel genes encoding SCR proteins in P. cactorum with similarity to the P. cactorum phytotoxic protein PcF. Together with the other two genes, scr96 was transcriptionally induced throughout the developmental and infection stages of the pathogen. These genes triggered plant cell death (PCD) in the Solanaceae, including Nicotiana benthamiana and tomato. The scr96 gene did not show single nucleotide polymorphisms in a collection of P. cactorum isolates from different countries and host plants, suggesting that its role is essential and non-redundant during infection. Homologues of SCR96 were identified only in oomycetes, but not in fungi and other organisms. A stable protoplast transformation protocol was adapted for P. cactorum using green fluorescent protein as a marker. The silencing of scr96 in P. cactorum caused gene-silenced transformants to lose their pathogenicity on host plants and these transformants were significantly more sensitive to oxidative stress. Transient expression of scr96 partially recovered the virulence of gene-silenced transformants on plants. Overall, our results indicate that the P. cactorum scr96 gene encodes an important virulence factor that not only causes PCD in host plants, but is also important for pathogenicity and oxidative stress tolerance.

  11. The Activation of Phytophthora Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b.

    Science.gov (United States)

    Kong, Guanghui; Zhao, Yao; Jing, Maofeng; Huang, Jie; Yang, Jin; Xia, Yeqiang; Kong, Liang; Ye, Wenwu; Xiong, Qin; Qiao, Yongli; Dong, Suomeng; Ma, Wenbo; Wang, Yuanchao

    2015-08-01

    Plant pathogens secrete an arsenal of effector proteins to impair host immunity. Some effectors possess enzymatic activities that can modify their host targets. Previously, we demonstrated that a Phytophthora sojae RXLR effector Avr3b acts as a Nudix hydrolase when expressed in planta; and this enzymatic activity is required for full virulence of P. sojae strain P6497 in soybean (Glycine max). Interestingly, recombinant Avr3b produced by E. coli does not have the hydrolase activity unless it was incubated with plant protein extracts. Here, we report the activation of Avr3b by a prolyl-peptidyl isomerase (PPIase), cyclophilin, in plant cells. Avr3b directly interacts with soybean cyclophilin GmCYP1, which activates the hydrolase activity of Avr3b in a PPIase activity-dependent manner. Avr3b contains a putative Glycine-Proline (GP) motif; which is known to confer cyclophilin-binding in other protein substrates. Substitution of the Proline (P132) in the putative GP motif impaired the interaction of Avr3b with GmCYP1; as a result, the mutant Avr3bP132A can no longer be activated by GmCYP1, and is also unable to promote Phytophthora infection. Avr3b elicits hypersensitive response (HR) in soybean cultivars producing the resistance protein Rps3b, but Avr3bP132A lost its ability to trigger HR. Furthermore, silencing of GmCYP1 rendered reduced cell death triggered by Avr3b, suggesting that GmCYP1-mediated Avr3b maturation is also required for Rps3b recognition. Finally, cyclophilins of Nicotiana benthamiana can also interact with Avr3b and activate its enzymatic activity. Overall, our results demonstrate that cyclophilin is a "helper" that activates the enzymatic activity of Avr3b after it is delivered into plant cells; as such, cyclophilin is required for the avirulence and virulence functions of Avr3b.

  12. Microbewerking met behulp van lasers

    NARCIS (Netherlands)

    Ezendam, M.M.M.

    1994-01-01

    Het bewerken van materialen met behulp van lasers staat momenteel enorm in de belangstelling, en terecht. De ontwikkeling van bestaande en nieuwe typen lasers staat alles behalve stil. Ontwikkelingen bevinden zich met name in het gebied van hogere vermogens, betere bundelkwaliteit en hogere

  13. Perspectief van lupine voor zaadwinning

    NARCIS (Netherlands)

    Schroeder, J.

    1987-01-01

    In 1985 en 1986 heeft een orienterend ondezoek plaatsgevonden naar de opbrengstmogelijkheden van witte lupine op zandgrond. Opbrengst en afrijping van de diverse onderzochte rassen bleven in beide jaren achter bij die van erwten en veldbonen. Dit was vooral in 1985 mede een gevolg van de slechte

  14. Een korte geschiedenis van filmgeluid

    NARCIS (Netherlands)

    Aalbers, Jasper

    2015-01-01

    abstractDe Franse filmtheoreticus Christian Metz stelde in 1973 dat film betekenis geeft door middel van vier kanalen. Drie van die kanalen betreffen geluid. Dit erkende belang van filmgeluid roept de verwachting op dat filmwetenschappers een aanzienlijk deel van hun aandacht zullen richten op het a

  15. Burnout : de stand van zaken

    NARCIS (Netherlands)

    Taris, T.; Houtman, I.L.D.; Schaufeli, W.

    2013-01-01

    Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten geleg

  16. Nieuwe mosdiertjes van noordzeewrakken (Bryozoa)

    NARCIS (Netherlands)

    Faassen, M.; Coolen, J.W.P.; Gittenberger, A.; Schrieken, N.

    2016-01-01

    In het kader van het project ‘Duik de Noordzee Schoon’ worden scheepswrakken
    onderzocht, beschreven en van afval ontdaan. Scheepswrakken vormen een bijzonder leefgebied in het mariene milieu, met een hoge biodiversiteit. Dit bleek weer tijdens onderzoek van visnetten die van ver weg gelegen

  17. Ingredienten voor kwaliteitsborging van modelonderzoek

    NARCIS (Netherlands)

    Grinsven JJM van; Haan BJ de; Braat LC; MNV; LBG; CIM

    1995-01-01

    In dit rapport wordt een aanzet gepresenteerd tot harmonisatie van de kwaliteitsborging van modelonderzoek in het RIVM. Het rapport komt voort uit initiatieven van leden van het Intersectoraal Modellen Overleg. Het rapport is in eerste instantie bedoeld voor onderzoekers die modellen ontwikkelen

  18. Kringloop als basis van bedrijfsvoering

    NARCIS (Netherlands)

    Linde, van der A.

    2007-01-01

    Gerard Keurentjes bekijkt zijn bedrijf als kringloop waarin grond en koeien de spil zijn. Het gebruik van microbiotica in plaats van antibiotica past daarin perfect. Een microbioticum bestaat uit een mengsel van acht kruiden opgelost in alcohol. Onderzoek toont aan dat het de productie van witte blo

  19. Burnout : de stand van zaken

    NARCIS (Netherlands)

    Taris, T.; Houtman, I.L.D.; Schaufeli, W.

    2013-01-01

    Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten

  20. Effectief leren van multimedia

    NARCIS (Netherlands)

    Kester, Liesbeth

    2013-01-01

    Kester, L. (2012, March). Effectief leren van multimedia [Effective learning from multimedia]. Keynote presented at a miniconference Learning Sciences of the Open University of the Netherlands, Eindhoven, the Netherlands.

  1. Effectief leren van multimedia

    NARCIS (Netherlands)

    Kester, Liesbeth

    2013-01-01

    Kester, L. (2012, March). Effectief leren van multimedia [Effective learning from multimedia]. Keynote presented at a miniconference Learning Sciences of the Open University of the Netherlands, Eindhoven, the Netherlands.

  2. Nematologische aspecten van kruidenteelten

    NARCIS (Netherlands)

    Beers, van T.G.; Molendijk, L.P.G.; Mheen, van der H.J.C.J.

    2005-01-01

    Het onderzoek heeft zich geconcentreerd op de kruiden maggi, valeriaan en peterselie en de aaltjes Pratylenchus penetrans, Paratrichodorus pachydermus en Meloidogyne chitwoodi. Uit de proeven en de inventarisatie van praktijkpercelen met valplekken is gebleken dat maggi, valeriaan en peterselie alle

  3. Phytophthora Root and Crown Rot on Apples in Bulgaria

    Directory of Open Access Journals (Sweden)

    Mariana Nakova

    2010-01-01

    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  4. Ellis Van Creveld syndrome

    Directory of Open Access Journals (Sweden)

    Shilpy S

    2007-05-01

    Full Text Available Ellis Van Creveld syndrome is a rare disorder and is a form of short-limbed dwarfism. It is an autosomal recessive disorder characterized by tetrad of disproportionate dwarfism, post-axial polydactyly, ectodermal dysplasia and heart defects. This case report presents a classical case of a seven-year-old boy with Ellis Van Creveld syndrome presented with discrete clinical findings.

  5. Caracterização morfofisiológica e análise de PCR-SSCP de isolados de Phytophthora da acácia-negra na região Sul do Brasil

    Directory of Open Access Journals (Sweden)

    Tatiane Cristina Albuquerque Alves

    2011-09-01

    Full Text Available O objetivo do trabalho foi caracterizar isolados de Phytophthora da acácia-negra (Acacia mearnsii provenientes do Sul do Brasil, com base em características fenotípicas tais como morfologia, crescimento micelial, características das culturas, compatibilidade sexual e patogenicidade, e em perfis de polimorfismo de conformação de fita simples (SSCP = Single Strand Conformation Polymorphism da região ITS-gene 5.8S do rDNA. Os isolados apresentaram esporângios com papilas proeminentes, arranjo dos esporângios irregularmente simpodial, culturas heterotálicas com presença de anterídios anfígenos, presença de clamidósporos e crescimento micelial em temperatura acima de 35°C, permitindo a classificação dos 12 isolados como P. nicotianae. Todos os isolados foram patogênicos, causando necrose em ramos de acácia-negra, sem formação de goma, com diferenças significativas de agressividade (p=0,05. Duas populações podem ser distinguidas em P. nicotianae da acácia negra pela análise PCR-SSCP do rDNA; no entanto essa separação não apresenta aparente correlação com características fenotípicas.

  6. Europese toetsing van algemene voorwaarden

    NARCIS (Netherlands)

    Loos, M.B.M.

    2001-01-01

    In deze bijdrage bespreekt Loos het Océano-arrest van het Hof van Justitie van 27 juni 2000, C-240/98 t/m C-244/98, NJ 2000, 730 (Océano Grupo Editorial SA et al./R. Murciano Quintero et al.). Uit de beslissing van het Hof van Justitie is af te leiden dat de rechter ambtshalve dient te toetsen of

  7. Space Van system update

    Science.gov (United States)

    Cormier, Len

    1992-07-01

    The Space Van is a proposed commercial launch vehicle that is designed to carry 1150 kg to a space-station orbit for a price of $1,900,000 per flight in 1992 dollars. This price includes return on preoperational investment. Recurring costs are expected to be about $840,000 per flight. The Space Van is a fully reusable, assisted-single-stage-to orbit system. The most innovative new feature of the Space Van system is the assist-stage concept. The assist stage uses only airbreathing engines for vertical takeoff and vertical landing in the horizontal attitude and for launching the rocket-powered orbiter stage at mach 0.8 and an altitude of about 12 km. The primary version of the orbiter is designed for cargo-only without a crew. However, a passenger version of the Space Van should be able to carry a crew of two plus six passengers to a space-station orbit. Since the Space Van is nearly single-stage, performance to polar orbit drops off significantly. The cargo version should be capable of carrying 350 kg to a 400-km polar orbit. In the passenger version, the Space Van should be able to carry two crew members - or one crew member plus a passenger.

  8. De trek van kruiden van volgroeid wortelmateriaal : handleiding van A tot Z in beknopte vorm

    NARCIS (Netherlands)

    Wijk, van C.A.P.

    2005-01-01

    Deze teelthandleiding richt zich op de trek van vooral dragon, krulpeterselie, rucola en munt, uitgaande van wortelmateriaal dat in de vollegrond wordt geteeld. Deze forcering richt zich zowel op aanbod van kruiden in potjes als de meermalige oogst van het gesneden product in een kas of een trekruim

  9. Methode van onderzoek voor residuen van bestrijdingsmiddelen afgeleid van triazines in levensmiddelen (Multimethode 7)

    NARCIS (Netherlands)

    Greve PA

    1988-01-01

    In dit rapport wordt een methode gegeven voor de clean-up van extracten m.b.v. gelpermeatiechromatografie (GPC) t.b.v. de bepaling van residuen van electron-captieve en organofosforbestrijdingsmiddelen. Een oudere versie van de GPC-methode, die alleen de organochloorbestrijdingsmiddelen omvatte,

  10. Opening van vier nieuwe laboratoria van de Afdeling der Werktuigbouwkunde van de Technische Hogeschool Delft

    NARCIS (Netherlands)

    Boon, E.F.; Boot, J.; Vahl, L.; Van Eldik Thieme, H.C.A.; Blok, H.

    1959-01-01

    Samenvatting van de toespraak door Prof.ir, R. van Hasselt bij de officiele opening van vier nieuwe laboratoriavan de Afdeling der Werktuigbouwkunde Boon, E.F. en Boot, J.: het Laboratorium voor Chemische Werktuigen Vahl, L.: het Laboratorium voor Koudetechniek Van Eldik Thieme, H.C.A.: het

  11. Occurrence of Phytophthora plurivora and other Phytophthora species in oak forests of southern Poland and their association with site conditions and the health status of trees.

    Science.gov (United States)

    Jankowiak, R; Stępniewska, H; Bilański, P; Kolařík, M

    2014-11-01

    Phytophthora plurivora and other Phytophthora species are known to be serious pathogens of forest trees. Little is known, however, about the presence of P. plurivora in Polish oak forests and their role in oak decline. The aims of this study were to identify P. plurivora in healthy and declining Quercus robur stands in southern Poland and to demonstrate the relationship between different site factors and the occurrence of P. plurivora. In addition, the virulence of P. plurivora and other Phytophthora species was evaluated through inoculations using 2-year-old oak seedlings. Rhizosphere soil was investigated from 39 oak stands representing different healthy tree statuses. The morphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the mitochondrial cox1 gene were used for identifications. P. plurivora, an oak fine root pathogen, was isolated from rhizosphere soil samples in 6 out of 39 stands. Additionally, Phytophthora cambivora, Phytophthora polonica and Phytophthora rosacearum-like were also obtained from several stands. The results showed a significant association between the presence of P. plurivora and the health status of oak trees. Similar relationships were also observed for all identified Phytophthora species. In addition, there was evidence for a connection between the presence of all identified Phytophthora species and some site conditions. Phytophthora spp. occurred more frequently in declining stands and in silt loam and sandy loam soils with pH ≥ 3.66. P. plurivora and P. cambivora were the only species capable of killing whole plants, producing extensive necrosis on seedling stems.

  12. Plaatsen van beschaafd vertier

    Directory of Open Access Journals (Sweden)

    James Kennedy

    2014-09-01

    Full Text Available Plaatsen van beschaafd vertier [Places of civilised amusement] by Jan Hein Furnée, which appeared as a PhD thesis in 2007 and was adapted and extended into a book in 2012, is regarded by historians of the Low Countries as an impressive tour de force. In a stimulating manner Furnée demonstrates with this profound urban history that for the elite of The Hague leisure activities played an important role in acquiring status and maintaining their position. His study is based on extensive and systematic research into a great variety of sources, from census registers, membership lists of clubs and societies to address books. This gives the reader an extraordinarily detailed picture of the changing social relations in the upper echelons of society in The Hague in the latter half of the nineteenth century. The sophisticated use of both qualitative and quantitative methods can serve as a model for other historians in the field of urban history. In a lively fashion Furnée shows that the inhabitants of The Hague grasped at all kinds of pastimes in order to distinguish themselves from others, and when possible to increase their own status through their participation in elegant societies, theatre visits or supporting the proposed zoo: but the book also makes statements about status and class, the history of gender and of politics at the end of the nineteenth century. Plaatsen van beschaafd vertier van Jan Hein Furnée dat in 2007 als proefschrift en in 2012 bewerkt en uitgebreid als boek verscheen, staat onder historici van de Lage Landen bekend als een imponerende tour de force. Op prikkelende wijze laat Furnée in deze diepgravende stadsgeschiedenis zien dat vrijetijdsbesteding voor Haagse elites een belangrijke rol speelde in standsvorming en handhaving van hun positie. Zijn studie is gebaseerd op uitgebreid en systematisch onderzoek van veelsoortige bronnen, van volkstellingsregisters, ledenlijsten van verenigingen en sociëteiten tot adresboeken

  13. An RxLR effector from Phytophthora infestans prevents re-localisation of two plant NAC transcription factors from the endoplasmic reticulum to the nucleus.

    Directory of Open Access Journals (Sweden)

    Hazel McLellan

    Full Text Available The potato late blight pathogen Phytophthora infestans secretes an array of effector proteins thought to act in its hosts by disarming defences and promoting pathogen colonisation. However, little is known about the host targets of these effectors and how they are manipulated by the pathogen. This work describes the identification of two putative membrane-associated NAC transcription factors (TF as the host targets of the RxLR effector PITG_03192 (Pi03192. The effector interacts with NAC Targeted by Phytophthora (NTP 1 and NTP2 at the endoplasmic reticulum (ER membrane, where these proteins are localised. Transcripts of NTP1 and NTP2 rapidly accumulate following treatment with culture filtrate (CF from in vitro grown P. infestans, which acts as a mixture of Phytophthora PAMPs and elicitors, but significantly decrease during P. infestans infection, indicating that pathogen activity may prevent their up-regulation. Silencing of NTP1 or NTP2 in the model host plant Nicotiana benthamiana increases susceptibility to P. infestans, whereas silencing of Pi03192 in P. infestans reduces pathogenicity. Transient expression of Pi03192 in planta restores pathogenicity of the Pi03192-silenced line. Moreover, colonisation by the Pi03192-silenced line is significantly enhanced on N. benthamiana plants in which either NTP1 or NTP2 have been silenced. StNTP1 and StNTP2 proteins are released from the ER membrane following treatment with P. infestans CF and accumulate in the nucleus, after which they are rapidly turned over by the 26S proteasome. In contrast, treatment with the defined PAMP flg22 fails to up-regulate NTP1 and NTP2, or promote re-localisation of their protein products to the nucleus, indicating that these events follow perception of a component of CF that appears to be independent of the FLS2/flg22 pathway. Importantly, Pi03192 prevents CF-triggered re-localisation of StNTP1 and StNTP2 from the ER into the nucleus, revealing a novel effector mode

  14. An RxLR effector from Phytophthora infestans prevents re-localisation of two plant NAC transcription factors from the endoplasmic reticulum to the nucleus.

    Science.gov (United States)

    McLellan, Hazel; Boevink, Petra C; Armstrong, Miles R; Pritchard, Leighton; Gomez, Sonia; Morales, Juan; Whisson, Stephen C; Beynon, Jim L; Birch, Paul R J

    2013-01-01

    The potato late blight pathogen Phytophthora infestans secretes an array of effector proteins thought to act in its hosts by disarming defences and promoting pathogen colonisation. However, little is known about the host targets of these effectors and how they are manipulated by the pathogen. This work describes the identification of two putative membrane-associated NAC transcription factors (TF) as the host targets of the RxLR effector PITG_03192 (Pi03192). The effector interacts with NAC Targeted by Phytophthora (NTP) 1 and NTP2 at the endoplasmic reticulum (ER) membrane, where these proteins are localised. Transcripts of NTP1 and NTP2 rapidly accumulate following treatment with culture filtrate (CF) from in vitro grown P. infestans, which acts as a mixture of Phytophthora PAMPs and elicitors, but significantly decrease during P. infestans infection, indicating that pathogen activity may prevent their up-regulation. Silencing of NTP1 or NTP2 in the model host plant Nicotiana benthamiana increases susceptibility to P. infestans, whereas silencing of Pi03192 in P. infestans reduces pathogenicity. Transient expression of Pi03192 in planta restores pathogenicity of the Pi03192-silenced line. Moreover, colonisation by the Pi03192-silenced line is significantly enhanced on N. benthamiana plants in which either NTP1 or NTP2 have been silenced. StNTP1 and StNTP2 proteins are released from the ER membrane following treatment with P. infestans CF and accumulate in the nucleus, after which they are rapidly turned over by the 26S proteasome. In contrast, treatment with the defined PAMP flg22 fails to up-regulate NTP1 and NTP2, or promote re-localisation of their protein products to the nucleus, indicating that these events follow perception of a component of CF that appears to be independent of the FLS2/flg22 pathway. Importantly, Pi03192 prevents CF-triggered re-localisation of StNTP1 and StNTP2 from the ER into the nucleus, revealing a novel effector mode-of-action to

  15. Identification of Phytophthora fragariae var. rubi by PCR.

    Science.gov (United States)

    Schlenzig, Alexandra

    2009-01-01

    The following chapter describes a PCR method for the identification of the raspberry root rot pathogen Phytophthora fragariae var. rubi. Furthermore, a nested PCR suitable for the detection of the pathogen in infected raspberry roots and validated against the "Duncan bait test" (EPPO Bull 35:87-91, 2005) is explained. Protocols for different DNA extraction methods are given which can be transferred to other fungal pathogens.

  16. Phytophthora Species, New Threats to the Plant Health in Korea

    OpenAIRE

    Ik-Hwa Hyun; Woobong Choi

    2014-01-01

    Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries ...

  17. Mortality of container-grown blueberry plants inoculated with Phytophthora cinnamomi Rands

    Science.gov (United States)

    We conducted four studies to evaluate the effect of Phytophthora cinnamomi isolates and inoculum delivery methods on root rot development and mortality of container-grown blueberry plants. Phytophthora cinnamomi isolates were obtained from the root zone of symptomatic blueberry plants and identifie...

  18. Does infection by southern root-knot nematode influence development of Phytophthora blight in pepper?

    Science.gov (United States)

    The southern root-knot nematode, Meloidogyne incognita, and Phytophthora capsici, the causal agent of Phytophthora blight, are both important pathogens of pepper (Capsicum annuum L.) in the U.S. and worldwide. Although there is significant information in the literature about the responses of pepper...

  19. Whole Genome Sequences of the Raspberry and Strawberry Pathogens Phytophthora rubi and P. fragariae.

    Science.gov (United States)

    Tabima, Javier F; Kronmiller, Brent A; Press, Caroline M; Tyler, Brett M; Zasada, Inga A; Grünwald, Niklaus J

    2017-10-01

    Phytophthora rubi and P. fragariae are two closely related oomycete plant pathogens that exhibit strong morphological and physiological similarities but are specialized to infect different hosts of economic importance, namely, raspberry and strawberry. Here, we report the draft genome sequences of these two Phytophthora species as a first step toward understanding the genomic processes underlying plant host adaptation in these pathogens.

  20. Host resistance to phytophthora fruit rot in U.S. watermelon plant introductions

    Science.gov (United States)

    Phytophthora capsici, distributed worldwide, is an aggressive pathogen with a broad host range, infecting solanaceous, leguminaceous, and cucurbitaceous crops. Phytophthora fruit rot of watermelon (Citrullus lanatus) caused by P. capsici was first reported in the U.S. in 1940. Since then, the dise...

  1. The expansion of Phytophthora clade 8b: three new species associated with winter grown vegetable crops

    NARCIS (Netherlands)

    Bertier, L.; Brouwer, H.; Cock, de A.W.A.M.; Cooke, D.E.L.; Olsson, C.H.B.; Höfte, M.

    2013-01-01

    Despite its association with important agricultural crops, Phytophthora clade 8b is a poorly studied group of species. The clade currently consists of three officially described species (Phytophthora porri, P. brassicae and P. primulae) that are host-specific pathogens of leek, cabbages and Primula

  2. Survival of southern highbush blueberry cultivars in Phytophthora Root Rot Infested fields in South Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of commercial blueberries and is most severe when blueberries are grown in wet soils with poor drainage. Symptoms of Phytophthora root rot include small, yellow or red leaves, lack of new growth, root necrosis, and a smaller root system than healthy plan...

  3. Fruit age and development of Phytophthora fruit rot on resistant and susceptible watermelon lines

    Science.gov (United States)

    Phytophthora fruit rot caused by Phytophthora capsici is an emerging disease in most watermelon producing regions of Southeast U.S. and has resulted in severe losses to watermelon growers especially in GA, SC, and NC. We recently released four germplasm lines (USVL203-PFR, USVL020-PFR, USVL782-PFR,...

  4. Molecular tools to unravel the role of genes from Phytophthora infestans

    NARCIS (Netherlands)

    West, van P.

    2000-01-01

    The oomycete plant pathogen Phytophthora infestans is the causal agent of potato late blight. P. infestans is undoubtedly the best known and most studied Phytophthora species today. This is mainly because it is such a

  5. Novel quantitative trait loci for partial resistance to Phytophthora sojae in soybean PI 398841

    Science.gov (United States)

    Phytophthora root and stem rot caused by Phytophthora sojae Kaufmann and Gerdmann is one of the most severe soybean [Glycine max (L.) Merr] diseases in the US. Partial resistance is as effective in managing this disease as single-gene (Rps) mediated resistance and is more durable. The objective of t...

  6. Molecular tools to unravel the role of genes from Phytophthora infestans

    NARCIS (Netherlands)

    West, van P.

    2000-01-01

    The oomycete plant pathogen Phytophthora infestans is the causal agent of potato late blight. P. infestans is undoubtedly the best known and most studied Phytophthora species today. This is mainly because it is such a devastating pathogen that can cause complete destruction of a potato field in only

  7. Resistance to Phytophthora cinnamomi among seedlings from backcross families of hybrid american chestnut

    Science.gov (United States)

    Steven N. Jeffers; Inga M. Meadows; Joseph B. James; Paul H. Sisco

    2012-01-01

    American chestnut (Castanea dentata (Marsh.) Borkh.) once was a primary hardwood species in forests of the eastern United States. Sometime during the late 18th century, it is speculated that Phytophthora cinnamomi, which causes Phytophthora root rot (PRR) on many woody plant species, was introduced to the southeast region of...

  8. Phytophthora megakarya, a causal agent of black pod rot in Africa

    Science.gov (United States)

    In most parts of the world where Theobroma cacao is grown, Phytophthora palmivora is the major concern for causing black pod rot (BPR). Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest ...

  9. Influence of fruit age on Phytophthora fruit rot development on susceptible and resistant watermelon germplasm

    Science.gov (United States)

    Phytophthora fruit rot of watermelon caused by Phytophthora capsici is an emerging disease in the southeastern United States. The disease has resulted in severe losses to watermelon growers in GA, SC, and NC, and is considered a top-research priority by the National Watermelon Association. We releas...

  10. Validation of the bait test with Rhododendron leaves for Phytophthora diagnosis

    Science.gov (United States)

    Corina Junker; Sabine Werres

    2017-01-01

    Bait tests are very helpful for diagnosis of Phytophthora in for example soil, substrate, water, sediment, and rootball samples (Werres and others 2014). By attracting the motile zoospores of the Phytophthora species with the baits these pathogens can be separated from other organisms. Bait tests are simple and cost...

  11. Urban activities influence on Phytophthora species diversity in British Columbia, Canada

    Science.gov (United States)

    Angela Dale; Nicolas Feau; Julien Ponchart; Guillaume Bilodeau; Jean Berube; R.C. Hamelin

    2017-01-01

    Phytophthora de Bary, a genus of Oomycetes, is known as a plant pathogenic genus. The best-known species infect a wide range of hosts, including economically valuable angiosperm and gymnosperm tree species and important agricultural crops. Many Phytophthora are invasive and have been disseminated through nursery and...

  12. Phytophthora andina sp nov., a newly identified heterothallic pathogen of solanaceous hosts in the Andean highlands

    NARCIS (Netherlands)

    Oliva, R.F.; Kroon, L.P.N.M.; Chacon, G.; Flier, W.G.; Ristaino, J.B.; Forbes, G.A.

    2010-01-01

    A blight disease on fruits and foliage of wild and cultivated Solanum spp. was found to be associated with a new species of Phytophthora. The proposed novel species is named Phytophthora andina Adler & Flier, sp. nov. based on morphological characteristics, pathogenicity assays, mitochondrial DN

  13. Phylogenetic Analysis of Phytophthora Species Based on Mitochondrial and Nuclear DNA Sequences

    NARCIS (Netherlands)

    Kroon, L.P.N.M.; Bakker, F.T.; Bosch, van den G.B.M.; Bonants, P.J.M.; Flier, W.G.

    2004-01-01

    A molecular phylogenetic analysis of the genus Phytophthora was performed, 113 isolates from 48 Phytophthora species were included in this analysis. Phylogenetic analyses were performed on regions of mitochondrial (cytochrome c oxidase subunit 1; NADH dehydrogenase subunit 1) and nuclear gene sequen

  14. Invasion of xylem of mature tree stems by Phytophthora ramorum and P. kernoviae

    Science.gov (United States)

    Anna Brown; Clive Brasier

    2008-01-01

    The aetiology and frequency of Phytophthoras in discoloured xylem tissue beneath phloem lesions was investigated in a range of broadleaved trees infected with P. ramorum, P. kernoviae and several other Phytophthoras. Isolation was attempted from the inner surface of 81, 6 x 4 cm sterilised...

  15. The interplay between a Phytophthora RXLR effector and an Arabidopsis lectin receptor kinase

    NARCIS (Netherlands)

    Bouwmeester, K.

    2010-01-01

    Phytophthora infestans – the causal agent of potato late blight – secretes a plethora of effector proteins to facilitate plant infection. The central subject of this thesis is ipiO, one of the first cloned Phytophthora genes with a putative function in pathogenicity as was anticipated based on its i

  16. Sporulation of Phytophthora ramorum and P. kernoviae on asymptomatic foliage and fruit

    Science.gov (United States)

    S. Denman; E. Moralejo; S.A. Kirk; E. Orton; A. Whybrow

    2008-01-01

    Phytophthora ramorum and P. kernoviae are newly discovered invasive Phytophthoras causing leaf necrosis, shoot tip dieback (mostly on ornamental and forest understorey host species) and bleeding cankers on tree trunks of a wide range of plant species. Both pathogens are now present in south-west England....

  17. Efficacy of fungicides against Phytophthora cactorum on Viola.

    Science.gov (United States)

    Blindeman, L; Heungens, K; Goossens, F; Gobin, B

    2009-01-01

    Phytophthora cactorum caused significant losses to pansies during the heat wave at the end of the summer of 2006. Infected plants showed foliage that appeared stunted and chlorotic, with wilting occurring even when soil moisture was adequate. When uprooted, symptomatic plants typically possess a surprisingly healthy looking and well-developed root system, but stem and root tissue at the soil interface is discoloured (purple to dark brown) and soft. Older Leaves turn yellow and when the stem base is attacked, the plant dies. Phytophthora cactorum was identified from stem and root tissue with both morphological and molecular techniques. To evaluate the efficacy of different fungicides against this pathogen, healthy plants were infected with zoospores of a Phytophthora cactorum isolate collected from commercial plants. Eleven fungicides were evaluated and compared to an untreated control. Two fungicides were applied via root drenching, 7 days before inoculation with zoospores of P. cactorum. The other fungicides were applied by spraying 24 hours after inoculation with P. cactorum. Preventive drenching with the combined formulation of fenamidone + fosethyl offered the best protection against P. cactorum, while drenching with dimethomorf also resulted in an obvious reduction in the number of infected plants. Foliar application was less successful, as only a combined formulation of mancozeb + metalaxyl-M gave sufficient protection. In conclusion, preventive drenching appears to be the best solution to prevent infection with P. cactorum, especially during warm weather periods, which are conducive to pathogen and disease development.

  18. Psigologiese benadering van pastorale arbeid

    Directory of Open Access Journals (Sweden)

    D. J. Strümpfer

    1969-03-01

    Full Text Available In die spreektaal van ons Afrikaanse kerke is ons lief om die bedienaar van die Woord aan te dui as „die predikant”, „die leraar” of „die dominee”. Miskien plaas ons met hierdie semantiese gebruik van terme wat lering en proklamering impliseer, ’n ongelukkige klem op die preekamp. Daarteenoor, het ons semanties miskien iets te leer van die Pinkstersektes wat die benaming „pastoor” verkies, of die Amerikaanse ge­ bruik van die term „the pastor”. Ons is wel lief om te praat van „ons herder en leraar”. Veelal word die herderlike, of pastorale, deel van die taak van die bedienaar van die Woord egter in sy eie gedagtes, asook in die gedagtes van sy gemeentelede, deur die leraarskap op die agtergrond gedwing. Al te dikwels word hy deur gemeentelede beskou as iemand wat op Sondag op die kansel gesien moet word en wat niks met die res van hul lewens te doen het nie. Herstel van die pastoraat sal deel moet wees van die proses om die ontkerstening van die hedendaagse lewe teen te gaan.

  19. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  20. Small homologous blocks in phytophthora genomes do not point to an ancient whole-genome duplication.

    Science.gov (United States)

    van Hooff, Jolien J E; Snel, Berend; Seidl, Michael F

    2014-05-01

    Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) and by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presence of 2HOM blocks, have been attributed to a whole-genome duplication (WGD) at the last common ancestor of Phytophthora. However, large intraspecies synteny-compelling evidence for a WGD-has not been detected. Here, we revisited the WGD hypothesis by deducing the age of 2HOM blocks. Two independent timing methods reveal that the majority of 2HOM blocks arose after divergence of the Phytophthora lineages. In addition, a large proportion of the 2HOM block copies colocalize on the same scaffold. Therefore, the presence of 2HOM blocks does not support a WGD at the last common ancestor of Phytophthora. Thus, genome evolution of Phytophthora is likely driven by alternative mechanisms, such as bursts of transposon activity.

  1. Leren van huisontruimingen

    Directory of Open Access Journals (Sweden)

    Gert Schout

    2011-11-01

    Full Text Available Preventing evictions Background. An eviction is a dramatic event. There is little knowledge on the process that precedes an eviction and how to prevent evictions. Method. An exploratory descriptive study based on seven case studies. Results. The process of a evictions is multifaceted and complex, but is determined by discontent over unfulfilled expectations, stereotyping, hardening, impotence, over-specialization, narrow-mindedness and lack of cooperation. Implications for practice that can be inferred from this study: institutionalize conflict capability. This means sensitivity to signals and signs of escalation, recognizing signs of hardening of positions, investing in skills and de-escalation skills like metacommunication and negotiation skills. Leren van huisontruimingen Achtergrond. Een huisontruiming is een ingrijpende gebeurtenis. Over hoe huisontruimingen verlopen en hoe ze zijn te voorkomen is weinig bekend. Methode. Een exploratief beschrijvend onderzoek gebaseerd op zeven casestudies. Resultaten. Het proces tot een huisontruiming is veelvormig en complex maar wordt bepaald door onvrede over niet ingeloste verwachtingen, stereotypering, verharding, onmacht, overspecialisatie, blikvernauwing en gebrekkige samenwerking. De volgende aanwijzing voor de praktijk kan worden afgeleid uit deze studie: institutionaliseer het vermogen om conflicten op constructieve wijze tegemoet te treden. Dit betekent het gevoelig worden voor signalen en voortekenen van escalatie, herkennen van tekenen van verharding van standpunten, het investeren in de-escaleren vaardigheden als metacommunicatie en onderhandelen.

  2. Variations in alkaloidal constituents of plant tissue cultures. [Nicotiana tabacum, Nicotiana rustica, Datura stramonium and Hyoscyamus niger

    Energy Technology Data Exchange (ETDEWEB)

    Essa, A.K.

    1987-01-01

    The accumulation of tobacco and Solanaceae-tropane alkaloids in calluses and suspensions of Nicotiana tabacum, Nicotiana rustica, Datura stramonium and Hyoscyamus niger was the main concern of this work. Nicotine, anabasine and anatabine had regularly been found in tobacco callus tissues grown for several passages. For the first time, N. tabacum suspensions were shown able to accumulate anabasine, anatabine, anatalline, myosmine and nicotelline whereas N. rustica calluses, N-methyl-, N,N-dimethyl- and N-methyl-N-nitroso anilines. The aim of these experiments was an attempt to affect the yields and types of alkaloids produced. The interrelationship between nicotine and protein contents in N. tabacum and N. rustica calluses was investigated. The possible role of urea and sodium propionate as precursors of nicotine in tobacco suspensions was checked by feeding the latter with carbon-14 radioactive substrates. The scope and quantum of the principle alkaloidal components present in the source N. tabacum plants and D. stramonium and H. niger seeds were investigated to stand as references against in vitro production. Identification of the products found was made by using gas chromatography-mass spectrometry (GC-MS) and/or MS.

  3. Diversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.

    Science.gov (United States)

    Scanu, Bruno; Linaldeddu, Benedetto T.; Deidda, Antonio; Jung, Thomas

    2015-01-01

    The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world’s vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago. PMID:26649428

  4. Diversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.

    Directory of Open Access Journals (Sweden)

    Bruno Scanu

    Full Text Available The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy. Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago.

  5. Die instelling van die doop

    Directory of Open Access Journals (Sweden)

    J. L. Venter

    1989-06-01

    Full Text Available Die eerste plek in die evangeliebeskrywings waar daar van die doop as ’n opdrag van Jesus Christus gepraat word en waar die betekenis die duidelikste uitkristalliseer, staan in Matteus 28 : 16 - 20. Heilshistories gesien, is dit die begin van kerklike inlywing van die wat gehoor het hoedat Jesus sy koninkryk proklameer, die evangelie aanvaar en tot bekering kom. Vir die doel van hierdie artikel word hierdie gedeelte ondersoek om te sien hoe die instelling geskied het, wat die plek en betekenis van die Christelike doop is.

  6. Competition between Phytophthora infestans effectors leads to increased aggressiveness on plants containing broad-spectrum late blight resistance.

    Directory of Open Access Journals (Sweden)

    Dennis A Halterman

    Full Text Available BACKGROUND: The destructive plant disease potato late blight is caused by the oomycete pathogen Phytophthora infestans (Mont. de Bary. This disease has remained particularly problematic despite intensive breeding efforts to integrate resistance into cultivated potato, largely because of the pathogen's ability to quickly evolve to overcome major resistance genes. The RB gene, identified in the wild potato species S. bulbocastanum, encodes a protein that confers broad-spectrum resistance to most P. infestans isolates through its recognition of highly conserved members of the corresponding pathogen effector family IPI-O. IpiO is a multigene family of effectors and while the majority of IPI-O proteins are recognized by RB to elicit host resistance, some variants exist that are able to elude detection (e.g. IPI-O4. METHODS AND FINDINGS: In the present study, analysis of ipiO variants among 40 different P. infestans isolates collected from Guatemala, Thailand, and the United States revealed a high degree of complexity within this gene family. Isolate aggressiveness was correlated with increased ipiO diversity and especially the presence of the ipiO4 variant. Furthermore, isolates expressing IPI-O4 overcame RB-mediated resistance in transgenic potato plants even when the resistance-eliciting IPI-O1 variant was present. In support of this finding, we observed that expression of IPI-O4 via Agrobacterium blocked recognition of IPI-O1, leading to inactivation of RB-mediated programmed cell death in Nicotiana benthamiana. CONCLUSIONS: In this study we definitively demonstrate and provide the first evidence that P. infestans can defeat an R protein through inhibition of recognition of the corresponding effector protein.

  7. Effecten van de verregening van EDTA-houdend zuivelafvalwater

    NARCIS (Netherlands)

    Drent, J.

    1981-01-01

    In een kolomproef en via literatuuronderzoek is het effect van verschillende gehalten aan EDTA (Ethyl-Diamine-Tetra-Azijnzuur) in het afvalwater op de gehalten van metaalionen in het drainwater onderzocht.

  8. Effecten van de verregening van EDTA-houdend zuivelafvalwater

    NARCIS (Netherlands)

    Drent, J.

    1981-01-01

    In een kolomproef en via literatuuronderzoek is het effect van verschillende gehalten aan EDTA (Ethyl-Diamine-Tetra-Azijnzuur) in het afvalwater op de gehalten van metaalionen in het drainwater onderzocht.

  9. Praktijkkennis van leerkrachten als ontwerpers van een ICT rijke leeromgeving

    NARCIS (Netherlands)

    Boschman, Ferry; McKenney, Susan; Voogt, Joke

    2011-01-01

    Ormel, B., Pareja, N., & McKenney, S. (2011, 8-10 June). Praktijkkennis van leerkrachten als ontwerpers van een ICT rijke leeromgeving. Presentation at the ORD annual meeting, Maastricht, The Netherlands.

  10. De functionele eigenschappen van suiker : de rol van suiker

    NARCIS (Netherlands)

    Boekel, van M.A.J.S.

    2010-01-01

    Suiker kan om veel verschillende redenen aan voeding worden toegevoegd. Om de zoete smaak natuurlijk, maar er is meer. Professor Tiny van Boekel van Wageningen Universiteit legt uit waarom suiker zo uniek is.

  11. Duurzaamheidsaspecten van de teelt en verwerking van energiegewassen in Zuidoost Nederland

    NARCIS (Netherlands)

    Conijn, J.G.; Corré, W.J.

    2009-01-01

    Resultaten van berekeningen van de effecten van teelt en verwerking van energiegewassen van vier verschillende ketens. De duurzaamheidsaspecten die aan bod komen zijn: vermindering fossiel energiegebruik en broeikasgas (BKG) emissie, behoud organische stof in de bodem, nitraatuitspoeling uit de bode

  12. Onderrig van Generasie Y

    Directory of Open Access Journals (Sweden)

    Elza Venter

    2016-02-01

    Full Text Available Generasie Y-leerders is jongmense wat ongeveer tussen 1977 en 2000 gebore is. Hierdie leerders het voor skerms grootgeword, ongeag of dit televisie-, rekenaar- of selfoonskerms was. Hulle is gebore in ’n samelewing waar inligting, opvoeding en vermaak net ’n klik ver was. Navorsers meen dat dié leerders se kritiese denke en ander kognitiewe vaardighede geaffekteer is omdat hulle ’n aansienlike hoeveelheid tyd daaraan bestee het om woorde en beelde passief te absorbeer, eerder as om met insig te lees. Leerders uit die generasie is dikwels ongemotiveerd en onbetrokke by hul eie leerervaring omdat hulle hul gelyktydig op ’n menigte digitale toestelle vermaak, terwyl die opvoeder hulle aandag probeer kry. Hulle verkies multitaakverrigting eerder as om op een taak of persoon op ’n slag te fokus en stel dikwels meer belang in wat op die skerm voor hulle aangaan as in wat die onderwyser hulle kan bied. Opvoeders op sekondêre en tersiêre vlak moet kennis hiervan neem en opnuut dink oor hulle onderrig- en leerstrategieë. Die klem in hierdie navorsing val op leerders, studente en opvoeders op sekondêre en tersiêre vlak. Die navorsing is deur die toepassing van ’n literatuuroorsig gedoen. Die hoofnavorsingsvraag van die studie is: ‘Hoe kan Generasie Y-leerders beter deur opvoeders by hulle eie leer in die klaskamer of lesinglokaal betrek word?’ Die twee subvrae is: (1 ‘Wat is sommige van die eienskappe van Generasie Y-leerders wat leer beïnvloed?’ en (2 ‘Watter onderrigstrategieë kan gebruik word om Generasie Y-leerders meer by hulle eie leer te betrek?’ Die outeur van hierdie artikel wil poog om opvoeders deur die literatuurstudie van riglyne in hierdie verband te voorsien.

  13. Feminisering van het basisonderwijs

    OpenAIRE

    Geerdink, Gerda

    2009-01-01

    In deze bijdrage ga ik in op wat feminisering van het onderwijs is en hoe we daar de afgelopen 25 jaar – zowel op de pabo als in het basisonderwijs – mee te maken hebben gekregen. De keerzijde is masculinisering en ik zal eveneens laten zien hoe zich dat in het onderwijs voordoet. Zowel feminisering als masculinisering hebben negatieve gevolgen. Ik wil duidelijk maken dat de gevolgen van de feminisering minder erg zijn dan we volgens de pers moeten geloven, maar dat het desondanks een ongewen...

  14. Analise van die Tswanaraaisel

    Directory of Open Access Journals (Sweden)

    S. A. Swanepoel

    1984-05-01

    Full Text Available ’n Strukturele, stilistiese en funksionele bcskrywing van die Twanaraaisel bring mee dat daar aan die volgende aspekte aandag gegee moet word: •\tWat is ’n raaisel en lioe word dit in Tswana genoem. •\tTot watter studiegebied en literere genre hoort die raaisel en watter subvorme kan vir Tswana onderskei word. •\tHoe sien die struktuur van Tswanaraaisels daar uit. •\tDeur wie, waar, wanneer en hoe word Tswanaraaisels voorgedra. •\tWatter stilistiese kenmcrke kan in Tswanaraaisels onderskei word. •\tWatter funksies vervul raaisels in ’n Tswanagcmeenskap.

  15. Kwantificering van variatie in resultaten van een waterkwaliteitsmodel als gevolg van onzekerheden bij calibratie van modelparameters; case study van de Biebrza, Polen

    NARCIS (Netherlands)

    Perk, van der M.; Bierkens, M.F.P.

    1995-01-01

    De fout in resultaten van een waterkwaliteitsmodel van de Biebrza in Polen, die het gevolg is van onzekerheden bij kalibratie van modelparameters, is gekwantificeerd. De gebruikte methode combineert kalibratie en gevoeligheidsanalyse. Het model is gevalideerd om de bekwaamheid ervan te toetsen, waar

  16. BOGO van groene grondstoffen naar biobased materialen. eigenschappen van polymerlkzuur

    NARCIS (Netherlands)

    Schennink, G.G.J.; Beukelaer, de H.J.; Molenveld, K.

    2013-01-01

    Deze opdracht geeft inzicht in de eigenschappen van PLA en daarmee de toepassingsmogelijkheden. Het praktijkdeel van deze opdracht laat zien hoe door keuze van de juiste PLA typen en temperatuurbehandeling de maximale gebruikstemperatuur (HDT=Heat Distortion Temperature) verhoogd kan worden.

  17. Toepassing van de basisvrachtbenadering op fosfaat van compost; advies

    NARCIS (Netherlands)

    Ehlert, P.A.I.

    2005-01-01

    Bij het vormgeven van het stelsel van gebruiksnormen is een maatschappelijke discussie ontstaan over de aanvoer van fosfaat met grond in compost en zwarte grond. Deze deskstudie gaat in op vragen die hierbij gesteld zijn. Het aandeel grond in compost en zwarte grond en de hoeveelheid fosfaat daarin

  18. Vervanging insecticiden : bestrijding van ritnaalden in de teelt van gladiool

    NARCIS (Netherlands)

    Conijn, C.G.M.; Breedeveld, M.E.

    2004-01-01

    Van alle schadelijke bodeminsecten bij bloembollen vormen ritnaalden bij de teelt van gladiolen de grootste bedreiging. Minder massaal, doch voor de teler desastreus, komen bonenvlieg, aardrupsen en emelten als plaag voor of worden bestrijdingsmaatregelen daartegen getroffen. Alleen aan de hand van

  19. Bestemming van schoolverlaters van het middelbaar agrarisch onderwijs

    NARCIS (Netherlands)

    Spierings, C.J.M.; Wolsink, G.H.

    1984-01-01

    Dit rapport geeft inzicht in de bestemming van schoolverlaters van het middelbaar agrarisch onderwijs. De resultaten zijn gebaseerd op een enquete in 1982/83 onder ruim 2000 jongens en meisjes, die in 1978 in de laatste klas zaten. Centraal stond de vraag wie en hoeveel van deze jongeren boer of tui

  20. Koperemissies als gevolg van het gebruik van aangroeiwerende verven

    NARCIS (Netherlands)

    Ros JPM

    1987-01-01

    Het gebruik van aangroeiwerende verven voor schepen leidt tot Cu-emissies. Bij werven is dat voornamelijk het gevolg van stralen en spuiten van verflagen. Voor 1985 is dit geschat op 32 ton. Er resulteert onder meer sterk verontreinigde baggerspecie. Modelberekeningen laten zien, dat vergaande d

  1. Aspecten van het beheer van Wilde zwijnen op de Veluwe

    NARCIS (Netherlands)

    Groot Bruinderink, G.W.T.A.; Lammertsma, D.R.

    2008-01-01

    Eens in de zoveel jaren, zoals afgelopen winter, zijn er veel berichten over overlast veroorzakende wilde zwijnen op de Veluwe. Welke factoren hebben geleid tot de enorme toename van de Sus scrofa? Op basis van kennis van de relatie tussen het wilde zwijn en mast worden een aantal mogelijke beheersc

  2. Bepaling van lasalocid-natrium door middel van HPLC

    NARCIS (Netherlands)

    Beek, W.M.J.; Buizer, F.G.

    1981-01-01

    Lasalocid-natrium is volgens methode EEG doc. 1089/VI/81-E onderzocht in twee mengvoeders. De storende invloed van monensin, salinomycine en narasin werd eveneens bekeken. Lasalocid-natrium wordt als coccidiostaticum toegepast voor het gebruik van kippen op een doseringsniveau van 75-150 ppm. De voo

  3. Kwaliteit van enkelvoudige extramurale ergotherapie: de bruikbaarheid van een meetinstrument.

    NARCIS (Netherlands)

    Janssen, B.; Sixma, H.

    2003-01-01

    Het NIVEL heeft in samenwerking met de NVE een meetinstrument ontwikkeld dat de kwaliteit van enkelvoudige extramurale ergotherapeutische zorg meet vanuit het perspectief van de cliënt. De QUOTE-EEE is ontstaan door schriftelijke vragenlijsten te versturen aan cliënten, van instellingen en praktijke

  4. Toepassing van de basisvrachtbenadering op fosfaat van compost; advies

    NARCIS (Netherlands)

    Ehlert, P.A.I.

    2005-01-01

    Bij het vormgeven van het stelsel van gebruiksnormen is een maatschappelijke discussie ontstaan over de aanvoer van fosfaat met grond in compost en zwarte grond. Deze deskstudie gaat in op vragen die hierbij gesteld zijn. Het aandeel grond in compost en zwarte grond en de hoeveelheid fosfaat daarin

  5. Winkel van de toekomst, toekomst van de winkel?

    NARCIS (Netherlands)

    Hofste, M. (Marleen); Teeuw, W.B. (Wouter)

    2012-01-01

    Dit boekje geeft de resultaten weer van het project Future Store van het Saxion Kenniscentrum Design en Technologie. Het gedrag, de behoeften van de consument, trends en de technologische ontwikkelingen veranderen in een rap tempo. Om deze veranderingen te kunnen bijbenen hebben retailers, MKB- bedr

  6. Sorptie van chloorfenolen in de bodem

    NARCIS (Netherlands)

    Lagas; P.; Snell; M.C.; Wytzes; H.

    1986-01-01

    Het sorptieproces alsmede de kinetiek van sorptie van chloorfenolen in natuurlijke en synthetische grondsoorten werd bestudeerd met behulp van laboratoriumexperimenten. Uit de resultaten bleek dat sorptie van chloorfenolen kan worden beschouwd als tweestapsproces. De eerste stap verloopt snel. D

  7. Kennis van de bacterieziekte ringrot groeit

    NARCIS (Netherlands)

    Custers, J.B.M.

    2002-01-01

    Kenmerken en verspreiding van ringrot in pootaardappelen. Gegevens in bijgaande tabel: Verspreiding van de ringrotbacterie binnen en tussen partijen pootgoed tijdens machinaal poten en de invloed van voorkieming en het ontsmetten van de machine hierop

  8. Big data en handschriften van Christiaan Huygens

    NARCIS (Netherlands)

    Damen, J.C.M.

    2013-01-01

    In de achtste aflevering van een serie combinatiebesprekingen (digitaalandspeciaal) schenkt Jos Damen aandacht aan een onderzoek naar big data van bibliotheekcatalogi en een catalogus van het werk van het Nederlandse genie Christiaan Huygens.

  9. De distributiestructuur van varkens in Nederland

    NARCIS (Netherlands)

    Driel, van J.A.

    1988-01-01

    Onderzoek naar de structuur van de afzet van levende varkens en biggen op basis van enquetes onder ruim 1000 varkenshouders en 150 veehandelaren. Het rapport beschrijft de situatie in 1986 en vergelijkt deze met die van 1973

  10. Oogst- en bewaartechnieken van wilgenstengels als energiegewas

    NARCIS (Netherlands)

    Gigler, J.K.; Sonneveld, C.

    1998-01-01

    IMAG-DLO onderzoekt de keten van teelt en logistiek van een aantal energiegewassen voor elektriciteitswinning. Voor dit onderzoek zijn hier verschillende experimenten uitgevoerd met de oogst van wilgenstengels. Wilgenteelt ten behoeve van energievoorziening

  11. Flotatieslib van slachterijen als voer voor varkens

    NARCIS (Netherlands)

    Smits, B.

    1984-01-01

    De belangrijkste resultaten worden weergegeven van de voederproeven met flotatieslib, slib dat ontstaat door uitvlokking van het afvalwater van slachterijen. In deze proeven is de voederwaarde en de gebruikswaarde van flotatieslib voor mestvarkens bepaald

  12. Verwachte economische effecten van uitbreidingsplannen

    NARCIS (Netherlands)

    Backus, G.; Bens, P.

    1994-01-01

    Vierentwintig varkenshouders hebben deelgenomen aan een onderzoek naar de effecten van voorgenomen uitbreidingsplannen. Gezinsuitgaven, betalingscapaciteit, ouderdom van de stallen en de uitbreidingsstrategie hebben een grote invloed op de bedrijfsresultaten

  13. Voer van invloed op biggensterfte

    NARCIS (Netherlands)

    Makkink, C.A.; Wientjes, J.G.M.

    2013-01-01

    Marginale verschillen in voeding en metabolisme vóór inseminatie kunnen leiden tot grote verschillen in prenatale en postnatale biggensterfte. Dit was een van de conclusies tijdens het seminar van de leerstoelgroep Adaptatiefysiologie in Wageningen University.

  14. De noodzaak van lokale verbindingen

    NARCIS (Netherlands)

    Jaarsma, C.F.; Heijman, W.J.M.; Voet, van der J.L.M.

    2004-01-01

    Het metropolitane landschap dreigt geleidelijk te worden versnipperd door aanleg en aanpassing van grootschalige infrastructuur. Dit artikel geeft een analyse van tijd en afstand, die nodig is, om aan openluchtrecreatie te doen: wandelen, fietsen, trimmen, paardrijden. Een onderverdeling is gemaakt

  15. Leibniz, metafysicus van het atoomtijdperk

    NARCIS (Netherlands)

    Romeijn, J.-W.

    2008-01-01

    Wat heeft de rekenkunde met de metafysica van doen? Massimo Mugnai laat ons in “Leibniz, Filosoof en Mathematicus” kennismaken met Leibniz als grondlegger van de logica. Maar dat is lang niet alles.

  16. De noodzaak van lokale verbindingen

    NARCIS (Netherlands)

    Jaarsma, C.F.; Heijman, W.J.M.; Voet, van der J.L.M.

    2004-01-01

    Het metropolitane landschap dreigt geleidelijk te worden versnipperd door aanleg en aanpassing van grootschalige infrastructuur. Dit artikel geeft een analyse van tijd en afstand, die nodig is, om aan openluchtrecreatie te doen: wandelen, fietsen, trimmen, paardrijden. Een onderverdeling is gemaakt

  17. Leibniz, metafysicus van het atoomtijdperk

    NARCIS (Netherlands)

    Romeijn, J.-W.

    2008-01-01

    Wat heeft de rekenkunde met de metafysica van doen? Massimo Mugnai laat ons in “Leibniz, Filosoof en Mathematicus” kennismaken met Leibniz als grondlegger van de logica. Maar dat is lang niet alles.

  18. U-box E3 ubiquitin ligase PUB17 acts in the nucleus to promote specific immune pathways triggered by Phytophthora infestans.

    Science.gov (United States)

    He, Qin; McLellan, Hazel; Boevink, Petra C; Sadanandom, Ari; Xie, Conghua; Birch, Paul R J; Tian, Zhendong

    2015-06-01

    Ubiquitination regulates many processes in plants, including immunity. The E3 ubiquitin ligase PUB17 is a positive regulator of programmed cell death (PCD) triggered by resistance proteins CF4/9 in tomato. Its role in immunity to the potato late blight pathogen, Phytophthora infestans, was investigated here. Silencing StPUB17 in potato by RNAi and NbPUB17 in Nicotiana benthamiana by virus-induced gene silencing (VIGS) each enhanced P. infestans leaf colonization. PAMP-triggered immunity (PTI) transcriptional responses activated by flg22, and CF4/Avr4-mediated PCD were attenuated by silencing PUB17. However, silencing PUB17 did not compromise PCD triggered by P. infestans PAMP INF1, or co-expression of R3a/AVR3a, demonstrating that not all PTI- and PCD-associated responses require PUB17. PUB17 localizes to the plant nucleus and especially in the nucleolus. Transient over-expression of a dominant-negative StPUB17(V314I,V316I) mutant, which retained nucleolar localization, suppressed CF4-mediated cell death and enhanced P. infestans colonization. Exclusion of the StPUB17(V314I,V316I) mutant from the nucleus abolished its dominant-negative activity, demonstrating that StPUB17 functions in the nucleus. PUB17 is a positive regulator of immunity to late blight that acts in the nucleus to promote specific PTI and PCD pathways.

  19. The Cell Death Triggered by the Nuclear Localized RxLR Effector PITG_22798 from Phytophthora infestans Is Suppressed by the Effector AVR3b.

    Science.gov (United States)

    Wang, Hongyang; Ren, Yajuan; Zhou, Jing; Du, Juan; Hou, Juan; Jiang, Rui; Wang, Haixia; Tian, Zhendong; Xie, Conghua

    2017-02-14

    Phytopathogenic oomycetes, such as Phytophthora infestans, potentially secrete many RxLR effector proteins into plant cells to modulate plant immune responses and promote colonization. However, the molecular mechanisms by which these RxLR effectors suppress plant immune responses are largely unknown. Here we describe an RxLR effector PITG_22798 (Gene accession: XM_002998349) that was upregulated during early infection of potato by P. infestans. By employment of agroinfiltration, we observed that PITG_22798 triggers cell death in Nicotiana benthamiana. Confocal microscopic examination showed that PITG_22798-GFP (Green Fluorescent Protein) located in the host nucleus when expressed transiently in N. benthamiana leaves. A nuclear localization signal (NLS) domain of PITG_22798 is important for nuclear localization and cell death-inducing activity. Sequence alignment and transient expression showed that PITG_22798 from diverse P. infestans isolates are conserved, and transient expression of PITG_22798 enhances P. infestans colonization of N. benthamiana leaves, which suggests that PITG_22798 contributes to P. infestans infection. PITG_22798-triggered cell death is dependent on SGT1-mediated signaling and is suppressed by the P. infestans avirulence effector 3b (AVR3b). The present research provides a clue for further investigation of how P. infestans effector PITG_22798 associates with and modulates host immunity.

  20. Gaschromatografisch onderzoek naar de samenstelling van de vluchtige olie van Mentha piperita L. gedurende de ontwikkeling van de plant

    NARCIS (Netherlands)

    Malingré, Theodorus Maria

    1966-01-01

    SAMENVATTING Het doel van het beschreven onderzoek was door middel van gaschromatografie, gecombineerd met andere analysemethoden, de samenstelling van de vluchtige olie van Mentha piperita L. en de veranderingen hierin gedurende de ontwikkeling van de plant, te bepalen en uit de resultaten van het

  1. Samenstelling van de vluchtige olie van Origanum vulgare L. ssp. vulgare gedurende de ontwikkeling van de plant

    NARCIS (Netherlands)

    Maarse, Henk

    1971-01-01

    INLEIDING EN DOEL VAN HET ONDERZOEK Vele onderzoekers hebben de laatste jaren de vorming van de verbindingen in vluchtige olien van planten bestudeerd door het bepalen van de verandering in de samenstelling van de vluchtige olie tijdens de groei van de plant. Lemli (68) wees als eerste op de noodzaa

  2. PHANTASTICA regulates development of the adaxial mesophyll in Nicotiana leaves.

    Science.gov (United States)

    McHale, Neil A; Koning, Ross E

    2004-05-01

    Initiation and growth of leaf blades is oriented by an adaxial/abaxial axis aligned with the original axis of polarity in the leaf primordium. To investigate mechanisms regulating this process, we cloned the Nicotiana tabacum ortholog of PHANTASTICA (NTPHAN) and generated a series of antisense transgenics in N. sylvestris. We show that NSPHAN is expressed throughout emerging blade primordia in the wild type and becomes localized to the middle mesophyll in the expanding lamina. Antisense NSPHAN leaves show ectopic expression of NTH20, a class I KNOX gene. Juvenile transgenic leaves have normal adaxial/abaxial polarity and generate leaf blades in the normal position, but the adaxial mesophyll shows disorganized patterns of cell division, delayed maturation of palisade, and ectopic reinitiation of blade primordia along the midrib. Reversal of the phenotype with exogenous gibberellic acid suggests that NSPHAN, acting via KNOX repression, maintains determinacy in the expanding lamina and sustains the patterns of cell proliferation critical to palisade development.

  3. Silicon delays Tobacco ringspot virus systemic symptoms in Nicotiana tabacum.

    Science.gov (United States)

    Zellner, Wendy; Frantz, Jonathan; Leisner, Scott

    2011-10-15

    Soluble silicon (Si) provides protection to plants against a variety of abiotic and biotic stress. However, the effects of Si on viral infections are largely unknown. To investigate the role of Si in viral infections, hydroponic studies were conducted in Nicotiana tabacum with two pathogens: Tobacco ringspot virus (TRSV) and Tobacco mosaic virus (TMV). Plants grown in elevated Si showed a delay in TRSV systemic symptom formation and a reduction in symptomatic leaf area, compared to the non-supplemented controls. TRSV-infected plants showed significantly higher levels of foliar Si compared to mock-inoculated plants. However, the Si effect appeared to be virus-specific, since the element did not alter TMV symptoms nor did infection by this virus alter foliar Si levels. Hence, increased foliar Si levels appear to correlate with Si-modulated protection against viral infection. This is all the more intriguing since N. tabacum is classified as a low Si accumulator.

  4. Phytophthora infestans POPULATION STRUCTURE: A WORLDWIDE SCALE Estructura poblacional de Phytophthora infestans: una escala global

    Directory of Open Access Journals (Sweden)

    MARTHA CÁRDENAS

    2012-05-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of the pathogen's population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep ( Pep tidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America, expanding it on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.Phytophthora infestans, el agente causal del tizón tardío de la papa y otros miembros de la familia de las Solanáceas, es el responsable de la gran hambruna irlandesa y aún hoy sigue causando grandes pérdidas económicas alrededor del planeta. Para establecer estrategias de control adecuadas contra este patógeno se requiere comprender la estructura poblacional del mismo. Mundialmente se han utilizado como marcadores las aloenzimas, Gpi (Glucosa-6-fosfato isomerasa y Pep (Peptidasa y la sonda de fingerprinting de RFLP (Polimorfismos de la Longitud de los Fragmentos de Restricción, RG57. De igual forma, la resistencia al fungicida metalaxyl y el tipo de apareamiento, han sido

  5. Gezamenlijke ontwikkeling van digitale leermaterialen

    NARCIS (Netherlands)

    Hermans, Henry; De Vries, Fred

    2005-01-01

    Hermans, H. & de Vries, F. (2004). Gezamenlijke ontwikkeling van digitale leermaterialen. In: Van Geloven, M., Koper, R. & Van der Veen, J., E-learning trends (pp. 19-21). Utrecht, Stichting Digitale Universiteit.
    Ook beschikbaar in dspace: http://hdl.han

  6. Effect van fasenvoedering op reproductie

    NARCIS (Netherlands)

    Peet-Schwering, van der C.M.C.; Smolders, M.M.A.H.H.

    2004-01-01

    Het verstrekken van minder stikstof en fosfor aan drachtige zeugen gedurende de eerste vier pariteiten verhoogt het percentage terugkomers bij zeugen van pariteit 1 en 2. De overige reproductiekenmerken worden niet beïnvloed door het verstrekken van minder stikstof en fosfor in het voer. Ook is er g

  7. Uitroeiing van schurft op varkensbedrijven

    NARCIS (Netherlands)

    Vesseur, P.; Bokma-Bakker, M.

    1999-01-01

    Het Praktijkonderzoek Varkenshouderij heeft in opdracht van 'Diergezondheid in Beweging' een methodiek ontwikkeld voor het schurftvrij maken van varkensbedrijven. Voor het breed in de praktijk introduceren van de methode zijn een folder en een videoband beschikbaar. Gezien het te verwachten positiev

  8. Gezamenlijke ontwikkeling van digitale leermaterialen

    NARCIS (Netherlands)

    Hermans, Henry; De Vries, Fred

    2005-01-01

    Hermans, H. & de Vries, F. (2004). Gezamenlijke ontwikkeling van digitale leermaterialen. In: Van Geloven, M., Koper, R. & Van der Veen, J., E-learning trends (pp. 19-21). Utrecht, Stichting Digitale Universiteit.
    Ook beschikbaar in dspace: http://hdl.han

  9. Verspanen van moeilijk bewerkbare materialen

    NARCIS (Netherlands)

    Hoogstrate, A.M.; Oosterling, J.A.J.

    2011-01-01

    Hier vindt u het boek over het verspanen van moeilijk bewerkbare materialen. Het is het resultaat van het TNO kennisoverdrachtproject “Verspanen van moeilijk bewerkbare materialen” Het bevat zowel achtergrondkennis als praktisch toepasbare richtlijnen en gegevens. Het is een introductie in dit onder

  10. Invloed van sport op speeksel

    NARCIS (Netherlands)

    G.J.H. Bruins; A. Vissink; E.C.I. Veerman; A. van Nieuw Amerongen

    2008-01-01

    Fysieke belasting zoals sportbeoefening kan van invloed zijn op de secretie en de samenstelling van speeksel. Bij intensieve lichamelijke inspanning daalt de concentratie van immunoglobulinen in speeksel, nemen de eiwitconcentratie - de output aan eiwitten (mg/min) blijft echter gelijk - en de visco

  11. Onverwachte gevolgen van endometriumablatie

    NARCIS (Netherlands)

    Voogd, I. de; Lagro-Janssen, A.L.M.

    2016-01-01

    Endometriumablatie kan uitkomst bieden voor vrouwen met hevig menstrueel bloedverlies bij wie medicamenteuze behandeling of een hormoonhoudend spiraaltje (LNG-IUD) onvoldoende effect oplevert. De nieuwste soort ablatiebehandeling, Novasure®, vindt plaats in 90% van de ziekenhuizen in Nederland. Bij

  12. Segments of van Gogh.

    Science.gov (United States)

    Mannlein, Sally

    2002-01-01

    Describes an art project that was used with first grade students in which they learn about Vincent van Gogh's style of painting. Explains that the children learn to create circles and straight lines and how to fill in with color. (CMK)

  13. Van Gogh's Sunflowers

    Science.gov (United States)

    Daddino, Michelle

    2010-01-01

    In this article, the author describes an art project wherein kindergarten students painted sunflowers. These beautiful and colorful sunflowers were inspired by the book "Camille and the Sunflowers" by Laurence Anholt, which does an amazing job of introducing young children to the art and life of Vincent van Gogh.

  14. Remembering Van Gogh.

    Science.gov (United States)

    Freifeld, Susan

    1999-01-01

    Describes an activity in which fourth grade students created a three-dimensional representation of Vincent Van Gogh's room in Arles (France). Expounds that the students had to invent their own strategies for three-dimensional construction and two-dimensional embellishment. Provides directions for creating the room and bed. (CMK)

  15. Van Bahrein tot Bitcoin

    NARCIS (Netherlands)

    Lodder, A.R.

    2014-01-01

    Door het internet kan de burger rechtstreeks contact krijgen met zijn publiek zonder hulp van derden als omroepen, kranten, uitgevers, muziekindustrie, etc. Bij al deze communicaties is prominent (Youtube) of minder prominent (Wordpress) een derde partij betrokken die de communicatie faciliteert. De

  16. Bacteriologisch Onderzoek van slachtdieren

    NARCIS (Netherlands)

    Engel HWB; van Leusden FM; Erne EHW

    1986-01-01

    Door zes vleeskeuringsdiensten en het RIVM werd gezamenlijk onderzoek verricht naar het in de Vleeskeuringswet omschreven "Bacteriologisch Onderzoek" (BO) bij slachtdieren. Doel was na te gaan of er verschillen zouden zijn in de aantallen positieve resultaten van het BO tussen de diensten

  17. Van Bahrein tot Bitcoin

    NARCIS (Netherlands)

    Lodder, A.R.

    2014-01-01

    Door het internet kan de burger rechtstreeks contact krijgen met zijn publiek zonder hulp van derden als omroepen, kranten, uitgevers, muziekindustrie, etc. Bij al deze communicaties is prominent (Youtube) of minder prominent (Wordpress) een derde partij betrokken die de communicatie faciliteert. De

  18. Zwartverkleuring van zandsteen

    NARCIS (Netherlands)

    Nijland, T.G.; Dubelaar, C.W.; Hees, R.P.J. van; Linden, T.J.M. van der

    2002-01-01

    Zwart- of grijsverkleuring van zandsteen in monumenten is een wijdverspreid fenomeen (Fig. 1). Sommige objecten danken er zelfs hun naam aan, denk aan de Porta Nigra in Trier. Deze zwartverkleuring, vaak aangeduid met de verwarrende en daarom ongelukkige term 'patina', wordt door velen ervaren als

  19. Het rendement van geluk

    NARCIS (Netherlands)

    Keijsers, J.; Jansen, M.; Ruland, E.

    2016-01-01

    Plaatste je twintig jaar geleden een zonnepaneel op je dak of deelde je de auto met de buren, dan behoorde je al snel tot de uitzonderingen in de samenleving, die elke vorm van financieel gewin de rug leek toe te keren. Dat maatschappelijke betrokkenheid en rendement hand in hand kunnen gaan, is een

  20. Verbeteren eetkwaliteit van stierenvlees

    NARCIS (Netherlands)

    Os, van M.; Heeres-van der Tol, J.J.; Kranen, R.W.; Eikelenboom, G.

    2001-01-01

    Deze eisen zullen de uniformiteit verbeteren, maar wat het effect is van deze factoren op de eetkwaliteit is echter minder bekend. Om hier inzicht in te krijgen heeft het Praktijkonderzoek Veehouderij in samenwerking met het ID-Lelystad een onderzoek uitgevoerd.

  1. Pythagoras Meets Van Hiele.

    Science.gov (United States)

    Flores, Alfinio

    1993-01-01

    Develops the Pythagorean Theorem in the context of the Van Hiele levels by presenting activities appropriate for each level. Activities point to preparatory development (level 0), give 3 different versions of Euclid's proof (levels 1, 2, and 3), give some generalizations of the theorem (level 3), and explore the Pythagorean relationship in other…

  2. Van profijtbeginsel naar rendementsdenken

    NARCIS (Netherlands)

    Gelderen, A.J.S. van

    2015-01-01

    Het ‘rendementsdenken’ is een ongelukkige verzamelnaam voor allerlei kwalen in het huidige hoger onderwijs. Verschillende vormen van rendement worden op een hoop gegooid en er gebeurt juist veel in het hoger onderwijs dat het ‘rendement’, óók het financiële rendement, juist niet ten goede komt. Dat

  3. Het importeren van honingbijen

    NARCIS (Netherlands)

    Cornelissen, B.

    2007-01-01

    Er wordt in de wereld volop gehandeld in bijen en bijenproducten. De globalisering is niet aan de bijenteelt voorbij gegaan. Producten als honing en propolis, maar ook raszuivere koninginnen worden over heel de wereld gemaakt en verspreid. Met deze wereldwijde verplaatsing van bijen kunnen ook aller

  4. Het importeren van honingbijen

    NARCIS (Netherlands)

    Cornelissen, B.

    2007-01-01

    Er wordt in de wereld volop gehandeld in bijen en bijenproducten. De globalisering is niet aan de bijenteelt voorbij gegaan. Producten als honing en propolis, maar ook raszuivere koninginnen worden over heel de wereld gemaakt en verspreid. Met deze wereldwijde verplaatsing van bijen kunnen ook

  5. Beschikbaarheid van biociden

    NARCIS (Netherlands)

    van der Grinten E; SEC; mev

    2012-01-01

    Beschikbaarheid van biociden:
    Biociden zijn middelen die de industrie en huishoudens gebruiken om schadelijke organismen te bestrijden. Biociden doorlopen een risicoanalyse voordat ze op de markt worden toegelaten. In 2009 is een handhavingsbeleid op niet-toegelaten middelen gestart. Middel

  6. Van Bahrein tot Bitcoin

    NARCIS (Netherlands)

    Lodder, A.R.

    2014-01-01

    Door het internet kan de burger rechtstreeks contact krijgen met zijn publiek zonder hulp van derden als omroepen, kranten, uitgevers, muziekindustrie, etc. Bij al deze communicaties is prominent (Youtube) of minder prominent (Wordpress) een derde partij betrokken die de communicatie faciliteert.

  7. De Pretertiaire Historie van den Indischen Archipel

    NARCIS (Netherlands)

    Umbgrove, J.H.F.

    1935-01-01

    Aan de hand van een serie kaartjes wordt in deze studie gepoogd de ontwikkeling van den Indischen Archipel — verspreiding van land en zee, faciesgebieden, tijden van transgressies, plooiingsperiodes etc. — in pretertiairen tijd voor zoover mogelijk na te gaan. Bij het vermelden van feiten en van lit

  8. Van wie zijn zij? De ambtenaren

    NARCIS (Netherlands)

    Peters, Jit

    2011-01-01

    Aan de hand van actuele voorbeelden gaat Jit Peters tijdens zijn afscheidscollege in op de toegenomen macht van ambtenaren. De loyaliteit van de ambtenaar is volgens hem nu te veel gericht op het ondersteunen van de eigen minister. Als tegenwichten van de macht van de ambtenaar staat Peters stil bij

  9. Verkenning van het hydrologische systeem van de Utrechte Heuvelrug met behulp van het model TRINS

    NARCIS (Netherlands)

    Snelting; H.; Pastoors; M.J.H.

    1985-01-01

    Voor de identificatie van het geohydrologische systeem in het onderzoek van de Utrechtse Heuvelrug is een eindige elementen model voor niet- stationaire grondwaterstroming gebruikt (het model TRINS). Het gesimuleerde systeemgedrag moet uiteraard aan de werkelijkheid worden getoetst. Voor deze to

  10. The expansion of Phytophthora clade 8b: three new species associated with winter grown vegetable crops.

    Science.gov (United States)

    Bertier, L; Brouwer, H; de Cock, A W A M; Cooke, D E L; Olsson, C H B; Höfte, M

    2013-12-01

    Despite its association with important agricultural crops, Phytophthora clade 8b is a poorly studied group of species. The clade currently consists of three officially described species (Phytophthora porri, P. brassicae and P. primulae) that are host-specific pathogens of leek, cabbages and Primula spp., respectively. However, over the past few decades, several other clade 8b-like Phytophthoras have been found on a variety of different host plants that were all grown at low temperatures in winter seasons. In this study, a collection of 30 of these isolates was subjected to a phylogenetic study using two loci (the rDNA ITS region and the mitochondrial cox1 gene). This analysis revealed a clear clustering of isolates according to their host plants. To verify whether these isolates belong to separate species, a detailed morphological study was conducted. On the basis of genetic and morphological differences and host specificity, we now present the official description of three new species in clade 8b: Phytophthora cichorii sp. nov., P. dauci sp. nov. and P. lactucae sp. nov. Two other groups of isolates (Phytophthora taxon castitis and Phytophthora taxon parsley) might also represent new species but the data available at this time are insufficient for an official description. This brings Phytophthora clade 8b to a group of six species that are all host-specific, slow-growing and specifically infect herbaceous crops at low temperatures.

  11. Four different Phytophthora species that are able to infect Scots pine seedlings in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2016-09-01

    Full Text Available To investigate susceptibility of young Scots pine seedlings to four Phytophthora species: Phytophthora cactorum, Phytophthora cambivora, Phytophthora plurivora and Phytophthora pini; seven-day-old seedlings of Scots pine (15 seedlings per experiment were infected using agar plugs of the respective species. Control group also consisted of 15 seedlings and was inoculated with sterile agar plugs. Results unambiguously show that after 4.5 days, all seedlings show clear signs of infection and display severe symptoms of tissue damage and necrosis. Moreover, three and two seedlings in the P. cactorum and P. cambivora infected seedlings groups, respectively, collapsed. The length of largest necrosis measured 13.4±3.90 mm and was caused by P. cactorum. To rule out any putative contamination or infection by secondary pathogens, re-isolations of pathogens from infection sites were performed and were positive in 100% of plated pieces of infected seedlings. All re-isolations were, however, negative in the case of the control group. Detailed microscopic analyses of infected tissues of young seedlings confirmed the presence of numerous Phytophthora species inside and on the surface of infected seedlings. Therefore, our results suggest Phytophthora spp. and mainly P. cactorum and P. cambivora as aggressive pathogens of Scots pine seedlings and highlight a putative involvement of these species in the damping off of young Scots pine seedlings frequently observed in forest nurseries.

  12. ANTIBACTERIAL ACTIVITY, PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY OF STEM OF NICOTIANA TABACUM

    National Research Council Canada - National Science Library

    Y Sharma; D Dua; A Nagar; N S Srivastava

    2016-01-01

    .... The purpose of this present study is to investigate the antibacterial activity, phytochemical screening and the antioxidant activity of aqueous and alcoholic extracts of the stem of Nicotiana tabacum...

  13. De rol van professionals bij schulden van jongeren. Voorkomen van schulden bij jongeren

    NARCIS (Netherlands)

    Pim van Heijst; Stijn Verhagen; Kitty Jurrius

    2010-01-01

    In het praktijkgerichte onderzoek dat we de afgelopen drie jaar vanuit het lectoraat Participatie en Maatschappelijke Ontwikkeling(PMO) van de Hogeschool Utrecht hebben gedaan, heeft de rol van professionals bij het voorkomen van schulden bij jongeren centraal gestaan. Naast overige actoren als

  14. Effecten van preventie. Deelrapport van de VTV 2010 Van gezond naar beter

    NARCIS (Netherlands)

    van den Berg M; Schoemaker CG; VTV; PZO; vz

    2010-01-01

    'Effecten van preventie' is het deelrapport van de Volksgezondheid Toekomst Verkenning 2010 over de effectiviteit van preventieve maatregelen en interventies. Sinds de Preventienota 'Kiezen voor gezond leven' uit 2006 hanteert de overheid in het preventiebeleid een vijftal speer

  15. Het monitoren van kwantiteit en kwaliteit van afvalwater van pangasiusvijvers in Vietnam

    NARCIS (Netherlands)

    Heijden, van der P.G.M.; Poelman, M.; Bosma, R.

    2011-01-01

    In 2010 hebben twee Vietnamese onderzoeksinstituten onder begeleiding van Wageningen UR het inkomende water en het water dat de vijvers van vier pangasiuskwekerijen verlaat, maandelijks bemonsterd en de gemonitord. Doel was om een simpele methode te vinden om hoeveelheid en kwaliteit van het afvalwa

  16. Vonken van Vernieuwing : een voorbeeld van vernieuwing van binnenuit in een lerarenopleiding

    NARCIS (Netherlands)

    Thölke, Jürg

    2010-01-01

    Het lectoraat innovatie van leren in organisaties aan de HAN bestaat uit een kerngroep van professionals met verschillende achtergronden. Wij richten ons in brede zin op de ontwikkeling van mens en organisatie. Hierin experimenteren wij met systemische werkvormen in het onderwijs, organisatieadvies,

  17. Eerste inventarisatie van de effecten van licht op het welzijn van (gezelschaps)dieren

    NARCIS (Netherlands)

    Bracke, M.B.M.; Wolthuis-Fillerup, M.

    2012-01-01

    Dit rapport geeft een eerste inventarisatie naar de effecten van licht op het welzijn van (gezelschaps)dieren. Aanleiding is het ontwerp Besluit Gezelschapsdieren waarin het algemene doelvoorschrift is opgenomen dat het licht moet voldoen aan de ethologische en fysiologische behoeften van de dieren.

  18. Eerste inventarisatie van de effecten van licht op het welzijn van (gezelschaps)dieren

    NARCIS (Netherlands)

    Bracke, M.B.M.; Wolthuis-Fillerup, M.

    2012-01-01

    Dit rapport geeft een eerste inventarisatie naar de effecten van licht op het welzijn van (gezelschaps)dieren. Aanleiding is het ontwerp Besluit Gezelschapsdieren waarin het algemene doelvoorschrift is opgenomen dat het licht moet voldoen aan de ethologische en fysiologische behoeften van de dieren.

  19. Kwaliteit van het stofbaden van leghennen, in de strooiselbak van de welzijnskooi

    NARCIS (Netherlands)

    Rooijen, van J.

    1998-01-01

    Het stofbaden van bruine leghennen (Isabrown) in de strooiselbak van de welzijnskooi is onderzocht. Een welzijnskooi is een grote kooi voor ongeveer 40 leghennen met een legnest, zitstokken en een strooiselbak om in te stofbaden. Welzijnskooien wordenontwikkeld om het welzijn van leghennen te

  20. Toepassing van grasstroken in laanbomen : optimaliseren van de groei laanbomen bij toepassing van grasstroken

    NARCIS (Netherlands)

    Sluis, van der B.J.

    2014-01-01

    In de teelt van laanbomen worden, met name op de zandgronden, op grote schaal grasstroken toegepast. In de teelt van laanbomen op kleigronden is dit nog zeer beperkt. Onder de kwekers neemt de belangstelling voor deze toepassing steeds meer toe, maar de voor- en nadelen van grasstroken zijn steeds o

  1. De statuur van Jan van Riebeeck en de betekenis van de volksplanting.

    Directory of Open Access Journals (Sweden)

    A. A. van Schelven

    1952-03-01

    Full Text Available In 1927 heeft wijlen de Leidse professor Knappert een aantal, aan Joan van Riebeeck’s Dagverhaal ontleende mededelingen in dezer voege samengevat: „het is van Riebeeck gegaan als vele groten van ons geslachl; hij heeft ervaren, dat . . . deucht met ondeucht geloont wert.” Noch in Amsterdam noch in Batavia hadden de bureaucraten veel met de Kaap op.

  2. Bewaren van onbeworteld stek : bewaring van onbeworteld stek van aster en solidago

    NARCIS (Netherlands)

    Eveleens, B.; Krijger, D.; Kouwenhoven, D.; Berg, van den T.; Telgen, van H.J.

    2002-01-01

    In de praktijk worden geoogste stekken van Aster ericoides en Solidago maximaal een week bewaard. Bij langere bewaring (of transport) treden vaak problemen op als uitval ten gevolge van rot en/of slechte beworteling. Een langere bewaarduur is gewenst, zowel voor planning van werkzaamheden als behoud

  3. Holland Media Groep of Luxemburg Media Groep: de trouvaille van de Raad van State

    NARCIS (Netherlands)

    Gronden, J.W. van de

    2001-01-01

    In de introductie van haar annotatie bij de uitspraak van de Rechtbank merkt C. van Boxtel op dat deze uitspraak de voorlaatste ronde is van de langdurige strijd tussen het Commissariaat voor de Media en HMG. Uit de uitspraak van de Afdeling Bestuursrechtspraak van de Raad van State - in deze beeld

  4. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Science.gov (United States)

    Amini, Jahanshir; Farhang, Vahid; Javadi, Taimoor; Nazemi, Javad

    2016-01-01

    In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC50) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC50 values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean EC50 values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases. PMID:26889111

  5. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Directory of Open Access Journals (Sweden)

    Jahanshir Amini

    2016-02-01

    Full Text Available In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC₅₀ values (ppm of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm. Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC₅₀ values for inhibition of the mycelial growth of P. capsici (31.473, P. melonis (33.097 and P. drechsleri (69.112, respectively. The mean EC₅₀ values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral (39.16% and z-citral (30.95% were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05. Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

  6. Werkafwesigheid: 'n Studie van vragmotorbestuurders

    Directory of Open Access Journals (Sweden)

    J. S. Gouws

    1995-06-01

    Full Text Available Absenteeism: A study of truck drivers. The aim of the study was to explore reasons for absenteeism as experienced by code 11 truck drivers. Two groups were identified: one group high, and the other group low on an absenteeism continuum. Significant differences between the groups ocurred with respect to four of the sixteen personality factors of the Sixteen Personality Factor Questionnaire. However, no significant difference in their personal values and intellectual ability could be found. Opsomming Die doel van die studie was die identifisering van aanduiders van werkafwesigheid by kode 11 vragmotorbestuurders. Die bevinding van hierdie studie is dat daar beduidende verskille tussen werkafwesige en werkaanwesige vragmotorbestuurders ten opsigte van vier van die sestien persoonlikheidsfaktore van die Sestien Persoonlik- heidsfaktorvraelys bestaan. Daar blyk egter geen beduidende verskille betreffende hulle persoonlike waardes en intellektuele vermoens te wees nie.

  7. Distribution and Virulence Diversity of Phytophthora sojae in China

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhen-dong; WANG Hua-bo; WANG Xiao-ming; CHANG Ru-zhen; WU Xiao-fei

    2004-01-01

    By investigating occurrence of Phytophthora root rot in fields and isolating P. sojae from diseased plants and soils, the distribution of P. sojae in China was surveyed. In addition to northeast region, P. sojae existed in Huanghe-Huaihe basin and Yangtze basin too. Eighty- three isolates of P. sojae isolated from different areas were identified on virulence using 13differential soybean cultivars, abundant virulence diversity was found in P. sojae. The greater diversity in virulence of P. sojae was in isolates from soil than from plants. And the greatest virulence diversity of P.sojae was found in Yangtze basin.

  8. Die gebruik van parallelplaatreologie vir die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat

    Directory of Open Access Journals (Sweden)

    O. C. Vorster

    2005-09-01

    Full Text Available Die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat word bemoeilik deur die feit dat daar tans slegs twee metodes in gebruik is. In die eerste metode word die bepaling deur middel van oplossingsviskometrie gedoen, maar die toksisiteit van die oplosmiddel, asook die tydperk wat dit neem om die bepaling te doen, is ’n probleem. Die tweede metode word beperk deur die kompleksiteit en beskikbaarheid van die apparatuur in Suid-Afrika. In hierdie studie word ’n alternatiewe metode, gebaseer op parallelplaatreologie, voorgestel wat albei hierdie probleme oorkom en die resultate sodoende verkry, word vergelyk met dié wat met bestaande metodes verkry is.

  9. Ellis-van Creveld

    Directory of Open Access Journals (Sweden)

    Dhandabani Jayaraj

    2012-01-01

    Full Text Available Ellis-van Creveld (EVC syndrome is an autosomal recessive disorder that is also known as chondro-ectodermal dysplasia. The common manifestations of this syndrome are short ribs, postaxial polydactyly, growth retardation, and ectodermal and cardiac defects. The present case report is about an 8-year-old boy who had the features of bilateral hexadactyly, knocked knees, cardiac problems, congenital absence of incisors, fused upper and lower labial frenulum, and mulberry molars.

  10. Electromagnetic van Kampen waves

    Energy Technology Data Exchange (ETDEWEB)

    Ignatov, A. M., E-mail: aign@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2017-01-15

    The theory of van Kampen waves in plasma with an arbitrary anisotropic distribution function is developed. The obtained solutions are explicitly expressed in terms of the permittivity tensor. There are three types of perturbations, one of which is characterized by the frequency dependence on the wave vector, while for the other two, the dispersion relation is lacking. Solutions to the conjugate equations allowing one to solve the initial value problem are analyzed.

  11. Van Wyk Louw Simbolis?

    Directory of Open Access Journals (Sweden)

    F. I.J. van Rensburg

    1990-05-01

    Full Text Available In this article the question is posed whether one is justified in associating N.P. van Wyk Louw’s work with Symbolism as seen in terms of its being a historical art movement. At first sight some of the main characteristics of his work seem incompatible with the overall spirit of Symbolism. A close look is taken at these characteristics. They are weighed against typical characteristics of Symbolism. A number of common traits are discovered. Following this, a study of Van Wyk Louw’s utterances in his prose works is undertaken to establish the extent of his knowledge of the works of Symbolists and of Symbolism as such, The unfolding history of his contact with their work and with Symbolism is traced. Some revealing relations are uncovered. Having established a number of definite Symbolist traits in his work, his poetical oeuvre is projected against the set of fundamental characteristics of Symbolism as a phenomenon identified by S. Dresden in his book Symbolisme (1980. Seen at against this background, the range of symbolist features in his work shows up clearly. The conclusion reached is that Van Wyk Louw so thoroughly absorbed those characteristics of Symbolism that corresponded with his own creative personality that they have blended almost imperceptibly with the rest of his oeuvre, thereby creating the impression that they are fully native to his work.

  12. Slow sand filters effectively reduce Phytophthora after a pathogen switch from Fusarium and a simulated pump failure.

    Science.gov (United States)

    Lee, Eric; Oki, Lorence R

    2013-09-15

    Slow sand filtration has been shown to effectively reduce Phytophthora zoospores in irrigation water. This experiment tested the reduction of Phytophthora colony forming units (CFUs) by slow sand filtration systems after switching the pathogen contaminating plant leachate from Fusarium to Phytophthora and the resilience of the system to a short period without water, as might be caused by a pump failure. The slow sand filtration system greatly reduced Phytophthora CFUs and transmission after switching the pathogens. In addition, Phytophthora reduction by the slow sand filter was equally effective before and after the simulated pump failure. Reduction of Fusarium was not seen by the SSFs, before or after the simulated pump failure. The results suggest that slow sand filters are effective at reducing larger organisms, such as Phytophthora zoospores, even after a pump failure or a change in pathogens.

  13. Phytophthora gemini sp. nov., a new species isolated from the halophilic plant Zostera marina in the Netherlands.

    Science.gov (United States)

    Man in 't Veld, Willem A; Rosendahl, Karin C H M; Brouwer, Henk; de Cock, Arthur W A M

    2011-08-01

    Eight strains belonging to the Oomycete genus Phytophthora were isolated from Zostera marina (seagrass) in The Netherlands over the past 25 y. Based on morphology, isozymes, temperature-growth relationships and ITS sequences, these strains were found to belong to two different Phytophthora species. Five strains, four of them isolated from rotting seeds and one isolated from decaying plants, could not be assigned to a known species and hence belong to a new species for which we propose the name Phytophthora gemini sp. nov. Three strains were isolated from decaying plants and were identified as Phytophthora inundata, thereby expanding the known habitat range of this species from fresh to brackish-saline areas. The possible role of both Phytophthora species in the decline of Z. marina in The Netherlands and the evolutionary significance of the presence of Phytophthora species in marine environments are discussed.

  14. Die voorgeskiedenis van kwantumberekening

    Directory of Open Access Journals (Sweden)

    P. H. Potgieter

    2004-09-01

    Full Text Available

    Die hoofidees wat tans gestalte vind in die teorie en tegnologie van kwantumberekening is in die laat 1970’s en vroeg 1980’s deur fisici in die Weste en ’n wiskundige in die voormalige Sowjetunie neergelˆ e. Dat di´ e teorie ook wortels in die Russiestalige vakliteratuur het, is nie algemeen bekend in die Weste nie. Daar word kortliks gekyk na die idee soos deur Benioff en (veral Feynman in die Weste versprei, asook die voorstel van di´ e rekengrondslag deur Manin in die Russiese literatuur. Die outeur hoop om hiermee so ’n onpartydig moontlike sintese van die vroe ¨ e gedagtegeskiedenis rondom kwantumberekening aan te bied. Die rol van omkeerbare en onomkeerbare berekeningsprosesse word vlugtig bekyk soos dit verband hou met die ontstaan van kwantumberekening, asook die sogenaamde Inligtingsparadoks in die fisika. Die inligtingsteorie en die fisika het heelwat met mekaar te kommunikeer, soos hierdie paradoks uitwys.

    Abstract

    The pre-history of quantum computation

    The main ideas behind developments in the theory and technology of quantum computation were formulated in the late 1970s and early 1980s by two physicists in the West and a mathematician in the former Soviet Union. It is not generally known in the West that the subject has roots in the Russian technical literature. The idea, as propagated by Benioff and (especially Feynman, is reviewed along with the proposition of a foundation for this kind of computation by Manin in the Russian literature. The author hopes to present as impartial a synthesis as possible of the early history of thought on this subject. The role of reversible and irreversible computational processes will be examined briefly as it relates to the origins of quantum computing and the so-called Information Paradox in physics. Information theory and physics, as this paradox shows, have much to communicate to each other.

  15. Onderzoek naar de affecten van de aanleg van damwanden en grondverdichting op tandwalvissen in het Dolfinarium Harderwijk

    NARCIS (Netherlands)

    Haan, de D.

    2013-01-01

    Voor het vaststellen van de effecten van de aanleg van damwandinstallaties en grondverdichting als onderdelen van het grootschalig bouwplan Waterfront Harderwijk van de gemeente Harderwijk werden op vijf verschillende locaties van het bouwplan installaties gesimuleerd en de geluidseffecten daarvan i

  16. Infection of Phytophthora capsici on pepper——Models and affecting factors

    Institute of Scientific and Technical Information of China (English)

    Xuemin LIU; Yanling ZHOU; Lijun LI

    2008-01-01

    Under controlled conditions in a growth chamber, we studied the mortality of pepper seedlings caused by Phytophthora capsici. The results showed that soil temperature and soil water content were important factors affecting their infection with P. capsici and the optimum condition for infection was found to be a soil temperature of 22℃-28℃ and a soil water content of 40%. The relationships of pepper seedling mortality caused by P. capsici along with soil temperature, soil water content and their interactions can be described by mathematical models. Field observations suggested that the Gompertz model was the best one for describing the epidemiological dynamics of the disease. The incidence of pepper phytophthora blight was significantly related to the initial incidence of pepper phytophthora blight, soil temperature, soil water content and air temperature. A forecasting model for pepper phytophthora blight in the field was developed.

  17. Disease Severity Rating of Chile Pepper Plants Inoculated with Phytophthora Capsici Collected in Taiwan

    Data.gov (United States)

    US Agency for International Development — The data are the phenotypic host reactions of a recombinant inbred line population of Capsicum annuum developed to differentiate races of Phytophthora capsici. The...

  18. Rapid isothermal detection of Phytophthora species on plant samples using recombinase polymerase amplification

    Science.gov (United States)

    Recently several isothermal amplification techniques have been developed that are extremely tolerant towards inhibitors present in many plant extracts. Recombinase polymerase amplification (RPA) assays for the genus Phytophthora have been developed which provide a simple and rapid method to macerate...

  19. Stability of partial resistance in potato cultivars exposed to aggressive strains of Phytophthora infestans

    NARCIS (Netherlands)

    Flier, W.G.; Bosch, van den G.B.M.; Turkensteen, L.J.

    2003-01-01

    Potato cultivars were evaluated for their resistance responses to aggressive strains of Phytophthora infestans in field and laboratory experiments. Analysis of variance revealed differential cultivar-by-isolate interactions for both foliar and tuber blight resistance. Differential responses occur as

  20. Rituele van plesier: Dolf van Coller se Die Bieliebalies

    Directory of Open Access Journals (Sweden)

    J. van Wyk

    1998-05-01

    Full Text Available Rituals of pleasure: Dolf van Coller’s Die Bieliebalies This article is an analysis of Dolf van Coller's Die Bieliebalies (1993, read as a hedonist text. It has many points of similarity with what Bakhtin (1984 called grotesque realism, and with Nietzsche’s views as expounded in The birth of tragedy (1956. By comparing Van Caller's text to that of Bakhtin and Nietzsche, a counter-discourse to contemporary moral discourses such as feminism is explored. Van Coller’s use of laughter as a relativising mechanism is very liberating in the context where petty morality intervenes dogmatically in the field of literature and other spheres of life.

  1. Highly Oxygenated Flavonoids from the Leaves of Nicotiana plumbaginifolia (Solanaceae

    Directory of Open Access Journals (Sweden)

    Md. Shafiullah Shajib

    2017-11-01

    Full Text Available Nicotiana plumbaginifolia Viv. is an annual herb of the family Solanaceae, which grows abundantly in the weedy lands of Bangladesh . This plant possesses analgesic, antibacterial, anti-anxiety and hepatoprotective properties, and produces various phenolic compounds including flavonoids. The present study afforded determination of total phenolic and flavonoid contents, and for the first time, the isolation and characterization of highly oxygenated flavonoids, e.g., 3,3' ,5,6,7,8-hexamethoxy- 4',5'-methylenedioxyflavone (1, 3,3' ,4' ,5',5,6,7,8-octamethoxyflavone (2, exoticin, 6,7,4',5'-dimethylenedioxy-3,5,3'-trimethoxyflavone (3 and ( 3,3' ,4',5,5',8-hexamethoxy-6,7-methylenedioxyflavone (4 from the leaves of N. plumbaginifolia . All these flavonoids are rather rare natural products, and only found in a few genera, e.g.,Polygonum and Murraya. The structures of the isolated flavonoids were elucidated by comprehensive spectroscopic analyses, e.g., UV, 1H, 13C NMR, DEPT, HSQC, HMBC and MS.

  2. Assessment of inoculation methods for screening black alder resistance to Phytophthora ×alni

    OpenAIRE

    Husson, Claude; Druart, P.; Marcais, Benoit

    2015-01-01

    Identification of resistance to Phytophthora xalni could provide the basis for a management strategy against alder decline in riparian ecosystems in Europe.[br/] This study aimed to test methods to evaluate the resistance of riparian alders to the disease, and to screen alder genotypes for resistance.[br/] Phytophthora xalni isolates were compared for their aggressiveness (lesion length on stem) and sporulation capacity (sporangia). While no difference in lesion lengths was found bet...

  3. Verspreide opstellen over de geschiedenis van Nederland

    OpenAIRE

    Huizinga, J.

    2007-01-01

    De bundel Verspreide opstellen over de geschiedenis van Nederland van Johan Huizinga is weliswaar uit een veelheid van bronnen samengesteld en de stukken stammen uit een periode van meer dan dertig jaren, maar zij laten bij de lezer een beeld van grote eenheid en samenhang achter. Of het nu gaat over de figuur van Willem van Oranje, over Leidens ontzet, over Hugo de Groot of over de invloed van Duitsland op de Nederlandse cultuur, Huizinga slaagt erin het nationale karakter van Nederland en o...

  4. Registratie van voedselinfecties en -vergiftigingen onderzocht door GGD's en Keuringsdiensten van waren, 1999

    NARCIS (Netherlands)

    van Duynhoven YTHP; de Wit MAS; CIE

    2000-01-01

    In deze rapportage worden de gegevens gepresenteerd van voedselinfecties en voedselvergiftigingen in Nederland in 1999. De resultaten zijn gebaseerd op meldingen door consumenten aan de Keuringsdienst van Waren, op standaard rapportages van onderzochte explosies van voedselinfecties en -vergiftigin

  5. Bepaling van enkele neurotransmitters, monoaminen, en metabolieten, met behulp van Continuous Flowapparatuur

    NARCIS (Netherlands)

    Eigeman L; Schonewille F; Borst M; van der Laan JW

    1986-01-01

    Bij het onderzoek in de psychofarmacologie kan kennis van de effecten van stoffen op de omzettingssnelheid van neurotransmitters een belangrijk aspect zijn. Met de huidige psychofarmaca lijken vooral de klassieke neurotransmitters zoals de monoaminen, noradrenaline, dopamine en serotonine van

  6. Achtergrondbelasting van het oppervlaktewater met zware metalen ten gevolge van uitspoeling uit de bodem

    NARCIS (Netherlands)

    Bonten, L.T.C.; Grift, B.; Klein, J.

    2007-01-01

    Uitspoeling van van nature in de bodem aanwezige metalen leiden tot een belasting van het oppervlaktewater. Modelberekeningen zijn uitgevoerd om deze achtergrondbelasting te schatten. Deze modelberekeningen zijn gebaseerd op schattingen van achtergrondgehaltes in de bodem voor de bovengrond en ondie

  7. Kwaliteit van de keuring en belasting van keurmeesters bij de pluimveekeuring

    NARCIS (Netherlands)

    Veerkamp, C.H.; Vries, de A.W.; Zegers, D.H.A.

    1989-01-01

    Onderzoek werd verricht aan 3 verschillende systemen van pluimveekeuring, waarbij is gelet op alle condities die van belang kunnen zijn voor de kwaliteit van de keuring en de belasting van de pluimveekeurmeesters

  8. Onderscheid tussen temporomandibulaire pijn en andere vormen van orofaciale pijn op basis van een vragenlijst

    NARCIS (Netherlands)

    Bonn, C.E.H.M.; van Selms, M.K.A.; te Poel, F.; Visscher, C.M.; Lobbezoo, F.; Naeije, M.

    2013-01-01

    Onderzocht werd of, los van de gebruikelijke instrumenten voor de diagnostiek van temporomandibulaire pijn, een vragenlijst onderscheid kan maken tussen temporomandibulaire pijn en andere vormen van chronische orofaciale pijn. Daarbij werd uitgegaan van het biopsychosociaal model. Er werden 509 pati

  9. Pyrosequencing of environmental soil samples reveals biodiversity of the Phytophthora resident community in chestnut forests.

    Science.gov (United States)

    Vannini, Andrea; Bruni, Natalia; Tomassini, Alessia; Franceschini, Selma; Vettraino, Anna Maria

    2013-09-01

    Pyrosequencing analysis was performed on soils from Italian chestnut groves to evaluate the diversity of the resident Phytophthora community. Sequences analysed with a custom database discriminated 15 pathogenic Phytophthoras including species common to chestnut soils, while a total of nine species were detected with baiting. The two sites studied differed in Phytophthora diversity and the presence of specific taxa responded to specific ecological traits of the sites. Furthermore, some species not previously recorded were represented by a discrete number of reads; among these species, Phytophthora ramorum was detected at both sites. Pyrosequencing was demonstrated to be a very sensitive technique to describe the Phytophthora community in soil and was able to detect species not easy to be isolated from soil with standard baiting techniques. In particular, pyrosequencing is an highly efficient tool for investigating the colonization of new environments by alien species, and for ecological and adaptive studies coupled with biological detection methods. This study represents the first application of pyrosequencing for describing Phytophthoras in environmental soil samples.

  10. Membrane-based oligonucleotide array developed from multiple markers for the detection of many Phytophthora species.

    Science.gov (United States)

    Chen, Wen; Djama, Zeinab Robleh; Coffey, Michael D; Martin, Frank N; Bilodeau, Guillaume J; Radmer, Lorien; Denton, Geoff; Lévesque, C André

    2013-01-01

    Most Phytophthora spp. are destructive plant pathogens; therefore, effective monitoring and accurate early detection are important means of preventing potential epidemics and outbreaks of diseases. In the current study, a membrane-based oligonucleotide array was developed that can detect Phytophthora spp. reliably using three DNA regions; namely, the internal transcribed spacer (ITS), the 5' end of cytochrome c oxidase 1 gene (cox1), and the intergenic region between cytochrome c oxidase 2 gene (cox2) and cox1 (cox2-1 spacer). Each sequence data set contained ≈250 sequences representing 98 described and 15 undescribed species of Phytophthora. The array was validated with 143 pure cultures and 35 field samples. Together, nonrejected oligonucleotides from all three markers have the ability to reliably detect 82 described and 8 undescribed Phytophthora spp., including several quarantine or regulated pathogens such as Phytophthora ramorum. Our results showed that a DNA array containing signature oligonucleotides designed from multiple genomic regions provided robustness and redundancy for the detection and differentiation of closely related taxon groups. This array has the potential to be used as a routine diagnostic tool for Phytophthora spp. from complex environmental samples without the need for extensive growth of cultures.

  11. Phytophthora terminalis sp. nov. and Phytophthora occultans sp. nov., two invasive pathogens of ornamental plants in Europe.

    Science.gov (United States)

    Man In 't Veld, Willem A; Rosendahl, Karin C H M; van Rijswick, Patricia C J; Meffert, Johan P; Westenberg, Marcel; van de Vossenberg, Bart T L H; Denton, Geoff; van Kuik, Fons A J

    2015-01-01

    In the past decade several Phytophthora strains were isolated from diseased Pachysandra terminalis plants suffering stem base and root rot, originating from the Netherlands and Belgium. All isolates were homothallic and had a felt-like colony pattern, produced semi-papillate sporangia, globose oogonia and had a maximum growth at ~ 27 C. Several additional Phytophthora strains were isolated from diseased Buxus sempervirens plants, originating from the Netherlands and Belgium, which had sustained stem base and root rot; similar strains also were isolated from Acer palmatum, Choisya ternata and Taxus in the United Kingdom. All isolates were homothallic and had a stellate colony pattern, produced larger semi-papillate sporangia and smaller globose oogonia than the isolates from Pa. terminalis and had a maximum growth temperature of ~ 30 C. Phylogenetic analyses of both species using the internal transcribed spacer region of the nuc rDNA (ITS), mt cytochrome oxidases subunit I gene (CoxI) and nuc translation elongation factor 1-α gene (TEF1α) revealed that all sequences of each species were identical at each locus and unique to that species, forming two distinct clusters in subclade 2a. Sequence analysis of partial β-tubulin genes showed that both taxa share an identical sequence that is identical to that of Ph. himalsilva, a species originating from Asia, suggesting a common Asian origin. Pathogenicity trials demonstrated disease symptoms on their respective hosts, and re-isolation and re-identification of the inoculated pathogens confirmed Koch's postulates.

  12. Phytophthora aquimorbida sp. nov. and Phytophthora taxon 'aquatilis' recovered from irrigation reservoirs and a stream in Virginia, USA.

    Science.gov (United States)

    Hong, Chuanxue; Richardson, Patricia A; Hao, Wei; Ghimire, Sita R; Kong, Ping; Moorman, Gary W; Lea-Cox, John D; Ross, David S

    2012-01-01

    Two distinct subgroups (L2 and A(-2)) were recovered from irrigation reservoirs and a stream in Virginia, USA. After molecular, morphological and physiological examinations, the L2 subgroup was named Phytophthora aquimorbida and the A(-2) designated as Phytophthora taxon 'aquatilis'. Both taxa are homothallic. P. aquimorbida is characterized by its noncaducous and nonpapillate sporangia, catenulate and radiating hyphal swellings and thick-walled plerotic oospores formed in globose oogonia mostly in the absence of an antheridium. P. taxon 'aquatilis' produces plerotic oospores in globose oogonia mostly with a paragynous antheridium. It has semi-papillate, caducous sporangia with variable pedicels, but it does not have hyphal swelling. Analyses of ITS, CO1, β-tubulin and NADH1 sequences revealed that P. aquimorbida is closely related to P. hydropathica, P. irrigata and P. parsiana, and P. taxon 'aquatilis' is related to P. multivesiculata. The optimum temperature for culture growth is 30 and 20 C for P. aquimorbida and P. taxon 'aquatilis' respectively. Both taxa were pathogenic to rhododendron plants and caused root discoloration, pale leaves, wilting, tip necrosis and dieback. Their plant biosecurity risk also is discussed.

  13. Optimalisatie bemesting Van Strien : voortgang 2013

    NARCIS (Netherlands)

    Hospers-Brands, A.J.T.M.; Strien, van J.

    2014-01-01

    Dit rapport bevat de resultaten van het derde jaar van het project “Bedrijfsinterne Optimalisatie”, en wel van het deelproject “Van Strien”. Op diverse percelen zijn metingen uitgevoerd aan de bodem om de stikstof werking van maaimeststoffen in beeld te krijgen.

  14. Electrospray ionisatie massaspectrometrie: Verkenning van het toepassingsgebied

    NARCIS (Netherlands)

    Heeft E van der; Hove GJ ten; Jong APJM de; LOC

    1996-01-01

    Betreft de resultaten van een studie naar de toepasbaarheid van electrospray ionisatie massaspectrometrie (ESI-MS). Er werd onderzoek verricht op het gebied van de eitwit- en peptide-analyse en de bepaling van polaire bestrijdingsmiddelen, macrolide antibiotica en metabolieten van polycyclische

  15. De syntaxis van de Italiaanse preposities

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In dit hoofdstuk wordt een inventaris opgesteld van de Italiaanse preposities die voorkomen in een corpus bestaande uit de romans La Ciociara van Moravia en Il Gattopardo van Tomasi di Lampedusa. Achtergrond voor de herkenning van preposities is de Extended Standard Theory van de gener

  16. Een nieuwe vorm van E-voedingswetenschap

    NARCIS (Netherlands)

    Kersten, A.H.; Schrauwen, P.; Müller, M.R.

    2008-01-01

    De informatiemaatschappij zorgt voor een nieuwe vorm van voedingswetenschap op het gebied van nutrigenomics, Nutritional Science 2.0. Voor het vermeerderen van kennis op dit terrein is een vrije mondiale uitwisseling van data nodig die nog niet goed van de grond is gekomen

  17. De syntaxis van de Italiaanse preposities

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In dit hoofdstuk wordt een inventaris opgesteld van de Italiaanse preposities die voorkomen in een corpus bestaande uit de romans La Ciociara van Moravia en Il Gattopardo van Tomasi di Lampedusa. Achtergrond voor de herkenning van preposities is de Extended Standard Theory van de

  18. Outsourcing van het ICT door overheidsinstellingen

    NARCIS (Netherlands)

    Kok, L.; Theeuwes, J.J.M.; Janssens, L.

    2003-01-01

    Het IWI heeft onlangs gewezen op de risico’s van outsourcing van ICT door het UWV. Ook het uitbesteden van ICT door gemeenten is niet zonder risico. Om outsourcingsbeslissingen van gemeenten en UWV te kunnen beoordelen wil het ministerie meer inzicht in de effecten van outsourcing. De directie

  19. Erkennen van een MOOC: een statusoverzicht

    NARCIS (Netherlands)

    Robert Schuwer

    2015-01-01

    Toekennen van studiepunten aan het succesvol volgen van een MOOC. Dit onderwerp is in de afgelopen jaren al meermalen aan bod gekomen bij discussies over mogelijke effecten van MOOC’s op het reguliere onderwijs. Medio 2014 verscheen een verkenning hierover van de NVAO (NVAO, 2014). Eén van de consta

  20. Kognitiewe en persoonlikheidskorrelate van aandaggewing

    Directory of Open Access Journals (Sweden)

    S. J. Vos

    1993-06-01

    Full Text Available Cognitive and personality correlates of attention. The principal aim of the study was to determine the cognitive and personality correlates of attention. Two contrasting groups were formed on the basis of scores from a self report inventory of attention. These two groups were compared in terms of the NSAG, the SAT, the 16PF and the JPQ. With the aid of the Hotelling T2 it was found that the vectors of means scores of the two contrasting groups differed statistically significantly from one another in respect of both the cognitive and personality variables. Opsomming Die hoofdoel van die studie was om die persoonlikheids- en kognitiewe korrelate van aandaggewing vas te stel. Twee kontrasterende groepe is saamgestel aan die hand van tellings op 'n selfverslaggewende vraelys oor aandaggewing. Hierdie twee groepe is met mekaar vergelyk ten opsigte van die NSAG, die SAT, die 16PF, en die JPV. Met behulp van Hotelling se T'toets is vasgestel dat die vektore van gemiddeldes van die twee groepe statistics beduidend van mekaar verskil ten opsigte van sowel die kognitiewe as die persoonlikheidsmetings.

  1. De volledigheidswaan van biografen

    Directory of Open Access Journals (Sweden)

    H. de Liagre Böhl

    2000-01-01

    Full Text Available A. Kuiper, Een wijze ging voorbij. Het leven van Abel J. Herzberg; L. van Driel, J. Noordegraaf, De Vries en Te Winkel. Een duografie; W. Hazeu, M.C. Escher. Een biografie; J.W. Renders, Zo meen ik dat ook jij bent. Biografie van Jan Hanlo; M. Derks, S. Verheesen-Stegeman, Wetenschap als roeping. Prof. dr. Christine Mohrmann (1903-1988, classica; F. Zwart, Willem Mengelberg (1871-1951. Een biografie 1871-1920The delusion that the scope of a biography is ever fully completeThis review article observes that, since the 1980s, the art of writing biographies has become fully accepted once more in academic circles in the Netherlands. This revival has been stimulated by positive collaborative efforts between historians and Dutch specialists. This harmony is based on their commitment to the principles of the Modem Biography, a style which counts since the first World War as the ‘ideal type’ of the whole genre. This style — which is mostly identified with Lytton Strachey’s Eminent Victorians (1918 - mediates between literature and historical studies. Their followers want to combine: 1. literary eloquence, 2. scholarly accuracy, 3. an analytic and a explicative concept about the personage and his or her work, 4. the skill of placing the character in the context of his or her time. Those four desiderata are used in this article as a point of departure for assessing six Dutch biographies that appeared in 1998. Some of them are excellent, however, all of them show a propensity towards empiricism and prolixity. Unfortunately this trait is characteristic of many recent biographies in The Netherlands

  2. De volledigheidswaan van biografen

    Directory of Open Access Journals (Sweden)

    H. de Liagre Böhl

    2000-01-01

    Full Text Available A. Kuiper, Een wijze ging voorbij. Het leven van Abel J. Herzberg; L. van Driel, J. Noordegraaf, De Vries en Te Winkel. Een duografie; W. Hazeu, M.C. Escher. Een biografie; J.W. Renders, Zo meen ik dat ook jij bent. Biografie van Jan Hanlo; M. Derks, S. Verheesen-Stegeman, Wetenschap als roeping. Prof. dr. Christine Mohrmann (1903-1988, classica; F. Zwart, Willem Mengelberg (1871-1951. Een biografie 1871-1920The delusion that the scope of a biography is ever fully completeThis review article observes that, since the 1980s, the art of writing biographies has become fully accepted once more in academic circles in the Netherlands. This revival has been stimulated by positive collaborative efforts between historians and Dutch specialists. This harmony is based on their commitment to the principles of the Modem Biography, a style which counts since the first World War as the ‘ideal type’ of the whole genre. This style — which is mostly identified with Lytton Strachey’s Eminent Victorians (1918 - mediates between literature and historical studies. Their followers want to combine: 1. literary eloquence, 2. scholarly accuracy, 3. an analytic and a explicative concept about the personage and his or her work, 4. the skill of placing the character in the context of his or her time. Those four desiderata are used in this article as a point of departure for assessing six Dutch biographies that appeared in 1998. Some of them are excellent, however, all of them show a propensity towards empiricism and prolixity. Unfortunately this trait is characteristic of many recent biographies in The Netherlands

  3. van der Waals torque

    Science.gov (United States)

    Esquivel-Sirvent, Raul; Schatz, George

    2014-03-01

    The theory of generalized van der Waals forces by Lifshtz when applied to optically anisotropic media predicts the existence of a torque. In this work we present a theoretical calculation of the van der Waals torque for two systems. First we consider two isotropic parallel plates where the anisotropy is induced using an external magnetic field. The anisotropy will in turn induce a torque. As a case study we consider III-IV semiconductors such as InSb that can support magneto plasmons. The calculations of the torque are done in the Voigt configuration, that occurs when the magnetic field is parallel to the surface of the slabs. The change in the dielectric function as the magnetic field increases has the effect of decreasing the van der Waals force and increasing the torque. Thus, the external magnetic field is used to tune both the force and torque. The second example we present is the use of the torque in the non retarded regime to align arrays of nano particle slabs. The torque is calculated within Barash and Ginzburg formalism in the nonretarded limit, and is quantified by the introduction of a Hamaker torque constant. Calculations are conducted between anisotropic slabs of materials including BaTiO3 and arrays of Ag nano particles. Depending on the shape and arrangement of the Ag nano particles the effective dielectric function of the array can be tuned as to make it more or less anisotropic. We show how this torque can be used in self assembly of arrays of nano particles. ref. R. Esquivel-Sirvent, G. C. Schatz, Phys. Chem C, 117, 5492 (2013). partial support from DGAPA-UNAM.

  4. Invloed van schermen en temperatuurbehandeling van het plantmateriaal op de groei en bloei van 3 freesia-rassen bij de teelt voor herfstbloei

    NARCIS (Netherlands)

    Doorduin, J.C.

    1983-01-01

    Onderzoek naar de invloed van verschil in lichtonderschepping door middel van schermen en de invloed van temperatuurbehandeling van het plantmateriaal op de groei, bloeitijdstip, kwaliteit en produktie van de freesiarassen Ballerina, Blue Heaven en Rosalinde

  5. Lumen - Gaia - Atlas : architectuur, kunst en tuinen van de gebouwen van de Environmental Sciences Group

    NARCIS (Netherlands)

    Windt, de R.; Londo, G.; Zaal, A.M.; Verstegen, T.; Ruyten, E.C.W.M.

    2010-01-01

    Boek ter gelegenheid van het afscheid van Hoogendooorn als bestuurslid van ESG, het onderdeel Groene Ruimte van Wageningen UR. Deze publicatie toont alle kunst binnen en buiten de drie gebouwen van ESG. Zo komen kunstuitingen bij elkaar, die eerder elders gestaan hebben (bij vroegere gebouwen van

  6. Huge van Bordeeus : een ridder van Karel de Grote op avontuur in het Oosten

    NARCIS (Netherlands)

    Lens, Maria Johanna

    2004-01-01

    'Huge van Bordeeus' is de dissertatie van Maria Lens. Hierin doet zij verslag van haar onderzoek naar de Middelnederlandse overlevering van een Franse tekst, 'Huon de Bordeaux', over de ridder Huge van Bordeeus. Deze veertiende-eeuwse ridder, leenman van Karel de Grote, moet de baard en vier tanden

  7. Aanwezigheid van ascosporen van Sclerotinia sclerotiorum binnen en buiten besmette percelen

    NARCIS (Netherlands)

    Lamers, J.G.; Wander, J.; Russchen, H.J.

    2012-01-01

    De aantasting van een gewas door Sclerotinia sclerotiorum hangt af van de aanwezigheid van ascosporen van deze schimmel in de lucht. In dit onderzoek dat gefinancierd wordt door PT en PA werd nagegaan in hoeverre de ascosporen van het eigen perceel afkomstig zijn of ook van een naburig perceel kunne

  8. Current status and prospects for the study of Nicotiana genomics, genetics, and nicotine biosynthesis genes.

    Science.gov (United States)

    Wang, Xuewen; Bennetzen, Jeffrey L

    2015-02-01

    Nicotiana, a member of the Solanaceae family, is one of the most important research model plants, and of high agricultural and economic value worldwide. To better understand the substantial and rapid research progress with Nicotiana in recent years, its genomics, genetics, and nicotine gene studies are summarized, with useful web links. Several important genetic maps, including a high-density map of N. tabacum consisting of ~2,000 markers published in 2012, provide tools for genetics research. Four whole genome sequences are from allotetraploid species, including N. benthamiana in 2012, and three N. tabacum cultivars (TN90, K326, and BX) in 2014. Three whole genome sequences are from diploids, including progenitors N. sylvestris and N. tomentosiformis in 2013 and N. otophora in 2014. These and additional studies provide numerous insights into genome evolution after polyploidization, including changes in gene composition and transcriptome expression in N. tabacum. The major genes involved in the nicotine biosynthetic pathway have been identified and the genetic basis of the differences in nicotine levels among Nicotiana species has been revealed. In addition, other progress on chloroplast, mitochondrial, and NCBI-registered projects on Nicotiana are discussed. The challenges and prospects for genomic, genetic and application research are addressed. Hence, this review provides important resources and guidance for current and future research and application in Nicotiana.

  9. A Distinct Endogenous Pararetrovirus Family in Nicotiana tomentosiformis, a Diploid Progenitor of Polyploid Tobacco1[w

    Science.gov (United States)

    Gregor, Wolfgang; Mette, M. Florian; Staginnus, Christina; Matzke, Marjori A.; Matzke, Antonius J.M.

    2004-01-01

    A distinct endogenous pararetrovirus (EPRV) family corresponding to a previously unknown virus has been identified in the genome of Nicotiana tomentosiformis, a diploid ancestor of allotetraploid tobacco (Nicotiana tabacum). The putative virus giving rise to N. tomentosiformis EPRVs (NtoEPRVs) is most similar to tobacco vein clearing virus, an episomal form of a normally silent EPRV family in Nicotiana glutinosa; it is also related to a putative virus giving rise to the NsEPRV family in Nicotiana sylvestris (the second diploid progenitor of tobacco) and in the N. sylvestris fraction of the tobacco genome. The copy number of NtoEPRVs is significantly higher in N. tomentosiformis than in tobacco. This suggests that after the polyploidization event, many copies were lost from the polyploid genome or were accumulated specifically in the diploid genome. By contrast, the copy number of NsEPRVs has remained constant in N. sylvestris and tobacco, indicating that changes have occurred preferentially in the NtoEPRV family during evolution of the three Nicotiana species. NtoEPRVs are often flanked by Gypsy retrotransposon-containing plant DNA. Although the mechanisms of NtoEPRV integration, accumulation, and/or elimination are unknown, these processes are possibly linked to retrotransposon activity. PMID:14988473

  10. Toepassing van ozon bij de bewaring van pootaardappelen

    NARCIS (Netherlands)

    Bus, C.B.; Veerman, A.

    2007-01-01

    In dit rapport wordt een onderzoek beschreven dat in een praktijkpootgoedbewaarplaats is uitgevoerd om te kijken naar de mogelijkheden van ontsmetting van pootgoed met ozongas. De knollen werden met een hoge concentratie ozon op de band behandeld tijdens het inschuren, met een lage concentratie cont

  11. Vorm en duur van thuiskraamzorg naar het oordeel van kraamvrouwen.

    NARCIS (Netherlands)

    Kerssens, J.J.

    1993-01-01

    De georganiseerde thuiskraamzorg is van groot belang in de Nederlandse verloskunde. Omdat de vraag naar kraamzorg het aanbod overtreft, is voldoende zorg echter niet meer overal beschikbaar. Steeds vaker worden minder uitgebreide vormen van kraamzorg geleverd en de gemiddelde verzorgingsduur voldoet

  12. Invloed van fosfaat op de strekkingsgroei van Kalanchoë

    NARCIS (Netherlands)

    Noort, van F.R.

    2010-01-01

    Hoewel door nieuwe compactere cultivars en door beter gebruik van groeiregulatoren het gebruik van groeiregulatoren is afgenomen, moet er nog steeds geremd worden om strekkingsgroei tegen te gaan en compacte Kalanchoës te telen. Vanuit diverse onderzoeken bij andere gewassen is bekend dat een

  13. Dutch Water Mining: Potentie van een zuiverend landschap van overvloed

    NARCIS (Netherlands)

    Os, van E.; Kruijs, A.; Bomas, B.; Poelman, M.; Pater, de M.; Bokhoven, van D.

    2012-01-01

    De blauwalg in het Volkerak - Zoommeer zorgt jaarlijks voor veel overlast. In de zomerperiode zijn giftig water en stank een hinderlijk fenomeen voor iedereen. Met de techniek Dutch Water Mining verdwijnt de overlast van blauwalgen. Voor de omliggende landbouwbedrijven ontstaat de zekerheid van een

  14. Betekenis van Legionella-soorten voor preventiebeleid van leidingwaterinstallaties

    NARCIS (Netherlands)

    Versteegh JFM; Brandsema PS; Lodder WJ; de Roda Husman AM; Schalk JAC; van der Aa NGFM; IMG; LZO; EPI

    2009-01-01

    Het RIVM adviseert om de huidige normstelling voor het preventiebeleid van Legionella te handhaven en niet uitsluitend op Legionella pneumophila te richten. Als andere Legionella-soorten worden aangetroffen kan er ook groei van Legionella pneumophila optreden. Als er dan geen maatregelen worden geno

  15. De invloed van bodemreiniging op de biologische beschikbaarheid van metalen

    NARCIS (Netherlands)

    Adema DMM*; Boer JLM de; Gestel CAM van; Jong P de*

    1987-01-01

    Er werd onderzoek uitgevoerd met als doel het uitlooggedrag en de biologische beschikbaarheid van metalen in verontreinigde gronden voor en na reiniging te bepalen. Dit (deel)rapport beschrijft de resultaten van het onderzoek naar de biologische beschikbaarheid. Op zes locaties in Nederland

  16. Opname en DNS strepieskodering van weekdiere en mosselkrewels van Robbeneiland

    Directory of Open Access Journals (Sweden)

    F.H. van der Bank

    2012-03-01

    Full Text Available Die Mollusca is die tweede grootste dierfilum. Dit sluit meer as 35 000 fossiel en 100 000 lewendespesies in. Die doel van hierdie studie was om ‘n opname te maak van die mosselkrewels, inheemse en uitlandse slakspesies op die eiland.

  17. Determinanten van de geneigdheid tot groupon-gebruik: toepassing van de theorie van gepland gedrag

    OpenAIRE

    Peeters, Andy

    2013-01-01

    In deze thesis wordt onderzocht welke factoren een invloed hebben op de Groupon proneness. Er wordt met andere woorden een onderzoek gedaan naar welke factoren er toe leiden dat mensen geneigd zijn om Groupon te gebruiken. De centrale onderzoeksvraag is: 'Welke factoren hebben een invloed op de geneigdheid om Groupon te gebruiken?' We gaan een antwoord geven op deze vraag aan de hand van de 'theorie van gepland gedrag', waarin we de theorie van de 'Big five' integreren. Vervolgens ...

  18. [Field resistance of Phytophthora melonis to metalaxyl in South China].

    Science.gov (United States)

    Wu, Yongguan; Lu, Shaofeng; Huang, Siliang; Fu, Gang; Chen, Liang; Xie, Dasen; Li, Qiqin; Cen, Zhenlu

    2011-08-01

    Phytophthora melonis is the casual agent of wax gourd and cucumber Phytophthora blight which becomes a constraint for sustainable production of the related crops. Metalaxyl is one of the principal fungicides for controlling the disease now. The objectives of the present study were: (1) to investigate the baseline sensitivity and field resistance of P. melonis to metalaxyl in South China; (2) to test the occurrence of metalaxyl-resistant mutants from metalaxyl-sensitive wild type strains exposed to the fungicide; and (3) to monitor the development of metalaxyl resistance in P. melonis population. Over 400 samples of wax gourd and cucumber Phytophthora blight were collected from Guangxi Zhuang Autonomous Region and Guangdong province during 2007-2010, and 193 strains of P. melonis were isolated and purified. The sensitivity of the isolated strains to metalaxyl was tested using mycelial growth rate method in vitro and floating-leaf-disk method in vivo, respectively. The metalaxyl-sensitive strains were induced on PDA plates containing 10 microg/mL metalaxyl. The sensitive, moderately resistant and resistant strains were recorded as 29.0% , 18.1% and 52.8%, respectively, among 193 tested strains. The frequency and level of resistance of P. melonis from Guangdong were higher than that from Guangxi. The strains from cucumber was generally more resistant to metalaxyl than those from wax gourd. The metalaxyl-resistant strains were frequently detected as predominant populations in most of the sampling sites and the highest resistance index (4226.9) was confirmed. Metalaxyl-resistant (M1r) mutants could be isolated from approximately 60% of the sensitive wild-type strains. The resistance level of the M mutants was 189-407 times higher than that of their sensitive parental strains. The EC50 values of 9 sensitive strains from a sampling site without a record of phenylamide fungicide application ranged from 0.0429 to 0.5461 microg/mL. Their mean EC50 value (0.3200 +/- 0

  19. Development of Phytophthora fruit rot resistant watermelon germplasm lines: USVL489-PFR, USVL782-PFR, USVL203-PFR and USVL020-PFR

    Science.gov (United States)

    Phytophthora capsici, distributed worldwide, is an aggressive pathogen with a broad host range, infecting solanaceous, leguminaceous, and cucurbitaceous crops. Phytophthora fruit rot of watermelon (Citrullus lanatus) caused by Phytophthora capsici was first reported in the U.S. in 1940. Since then...

  20. Afscheid van de stapelmarkt

    Directory of Open Access Journals (Sweden)

    J.W. Veluwenkamp

    2003-01-01

    Full Text Available C. Lesger, Handel in Amsterdam ten tijde van de Opstand. Kooplieden, commerciële expansie en verandering in de ruimtelijke economie van de Nederlanden ca. 1550-ca. 1630 Farewell to the Staple Market, Jan Willem VeluwenkampLesger argues that Amsterdam's essential function in international trade in the seventeenth century was turnover promotion through price stabilisation. Claiming that the relevant mechanism involved information provision rather than stockpiling, he convincingly bids farewell to the historiographical tradition of the Amsterdam staple market and introduces Amsterdamas the centre of information provision. I contest two aspects of Lesger's argument. Unlike him, I do not think that information provision was decisive in Amsterdam's commercial expansion around 1600: Prior to 1585, information exchange and expansion were characteristic for Antwerp too. The Amsterdam acceleration essentially involved the penetration of Asia and the Atlantic area, which was mainly provoked by the war. In addition, I think that Lesger underestimates the Dutch intermediate trade. On the one hand, Dutch industry-related import and export were more significant than he indicates. On the other hand, he attaches too little meaning to the fact that Dutchmen dominated international commerce even when they did not steer all commodity flows via the Dutch Republic.