Morphologic, Molecular, and Pathogenic Characterization of Diaporthe phaseolorum Variability in the Core Soybean-Producing Area of Argentina     

Pioli RN  Morandi EN  Martínez MC  Lucca F  Tozzini A  Bisaro V  Hopp HE 《Phytopathology》2003,93(2):136-146

ABSTRACT Isolates of the Diaporthe/Phomopsis (D/P) complex were collected in the main soybean producing area of Argentina during the 1996-97, 1997-98, and 1998-99 growing seasons. Twenty-three morphologic characters related to type of colonies, stroma, pycnidia and conidia, presence of perithecia, and asci length were studied by principal component analysis (PCA). Genomic DNA were analyzed by the random amplified polymorphic DNA (RAPD) technique. From both studies, 18 isolates were identified as D/P complex and grouped in four major taxa: (i) Diaporthe phaseolorum var. meridionalis, (ii) D. phaseolorum var. caulivora, (iii) D. phaseolorum var. sojae, and (iv) Phomopsis longicolla. In addition to distinguishing interspecific and intraspecific variability, molecular markers allowed the detection of differences among isolates within the same variety. Pathogenicity was assayed in the greenhouse, by the toothpick method, inoculating the D/P isolates to soybean genotypes carrying different resistance genes (Rdc1, Rdc2, Rdc3, and Rdc4) against soybean stem canker (SSC). Pathogenic analysis distinguished two main groups: (i) the SSC-producing isolates, including D. phaseolorum var. meridionalis and D. phaseolorum var. caulivora, and (ii) the non-SSC-producing isolates, including D. phaseolorum var. sojae and P. longicolla. Cultivar RA-702 (susceptible control) was compatible with both D. phaseolorum var. meridionalis and D. phaseolorum var. caulivora isolates; meanwhile, Tracy-M (Rdc1 and Rdc 2 genes) was incompatible with D. phaseolorum var. meridionalis but compatible with D. phaseolorum var. caulivora isolates. The fact that Rdc1 and Rdc2 together (as in Tracy-M) confer an almost immune reaction to all assayed isolates of D. phaseolorum var. meridionalis but were ineffective against the D. phaseolorum var. caulivora isolates evaluated suggests that the virulence or avirulence genes in D. phaseolorum var. meridionalis and D. phaseolorum var. caulivora are different. Moreover, physiological races of D. phaseolorum var. meridionalis were detected by using differential soybean genotypes carrying distinct single Rdc genes. As far as we know, this is the first report on the existence of physiological races of D. phaseolorum var. meridionalis in South America. Selective pressure due to deployment of resistant host cultivars may have changed the frequency of the virulence or avirulence genes within the population of D. phaseolorum var. meridionalis. On the whole, our results show that pathogenic variability of D. phaseolorum in the core soybean-producing area of Argentina is higher than previously recognized.  相似文献   

Pathogenesis and clinical aspects of Aujeszky's disease in cattle following an experimental infection through the respiratory, digestive and genital organs and through the skin     

W Hopp  K H Witte  D Prager 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1985,32(4):287-305

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Feasibility of integration of molecular markers and morphological descriptors in a real case study of a plant variety protection system for soybean     

S. Giancola  S. Marcucci Poltri  P. Lacaze  H.E. Hopp 《Euphytica》2002,127(1):95-113

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Variation in extraction efficiency between juvenile and adult oribatid mites: Ameronothrus lineatus (Oribatida, Acari) in a Macfadyen high-gradient canister extractor     

Guldborg Søvik  Hans Petter Leinaas 《Pedobiologia》2002,46(1):34-41

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Fluorescence of muscle and connective tissue from cod and salmon   总被引：1，自引：0，他引：1  

Andersen CM  Wold JP 《Journal of agricultural and food chemistry》2003,51(2):470-476

Autofluorescence of salmon and cod muscle was measured and compared with autofluorescence of collagen type I and type V. Similarities between fluorescence of fish muscle and collagen were found in that the same peaks were obtained around 390, 430, and 480 nm. These similarities are supported by principal component analyses. Texture and gaping score were predicted from the fluorescence spectra by partial least-squares regression. However, the predictions did not perform well. Relating fluorescence to the gaping score gave a prediction error of 0.91 and a correlation of 0.43 when measuring gaping on a scale from 0 to 5. There was no relation between texture and fluorescence spectra. Fluorescence of fish muscle could be related to the storage time. However, this relation seemed not to be induced by changes in collagen.  相似文献   

EPPO Study on the Risk of Imports of Plants for Planting: description and details of the first outcomes     

F. Grousset  F. Petter  M. Suffert  A. S. Roy 《EPPO Bulletin》2012,42(2):185-190

EPPO member countries requested that a study be conducted to identify and better address the risks presented by the trade of plants for planting, which has led to numerous introductions of pests into the EPPO region in recent years. Concerns were raised about the efficacy of the current plant health systems in place in the EPPO region to deal with the risks presented by plants for planting. The EPPO Study on the Risk of Imports of Plants for Planting was launched by the EPPO Council in 2010. The first part of the Study was completed in spring 2012. It was published as EPPO Technical Document 1061 ( http://www.eppo.int/QUARANTINE/EPPO_Study_on_Plants_for_planting.pdf ). Examples of pest outbreaks in the EPPO region suspected to be caused by international trade of plants for planting were analyzed. This analysis identified characteristics of the pest/crop/trade patterns associated with the risks of importing pests. These characteristics are described as criteria that are intended to be used in a screening process to enable identification of commodities that require an assessment prior to import in the EPPO region. The further elaboration of the screening process is briefly outlined.  相似文献   

P0 protein of cotton leafroll dwarf virus-atypical isolate is a weak RNA silencing suppressor and the avirulence determinant that breaks the cotton Cbd gene-based resistance     

Y. C. Agrofoglio  V. C. Delfosse  M. F. Casse  H. E. Hopp  I. Bonacic Kresic  V. Ziegler-Graff  A. J. Distéfano 《Plant pathology》2019,68(6):1059-1071

Cotton blue disease (CBD) is the most important disease present in cotton crops in South America and cotton leafroll dwarf virus (CLRDV) is the causal agent. The disease has been controlled by sowing cotton varieties resistant to CLRDV. However, in the 2009/10 growing season, an outbreak due to an atypical CLRDV isolate (CLRDV-at) occurred in northwest Argentina. Although CLRDV and CLRDV-at genomes are very closely related, the symptoms they produce in cotton plants are quite different. P0 is the most divergent protein between the isolates and in CLRDV is a silencing suppressor protein. This work characterized the silencing suppressor activity of the P0 protein encoded by CLRDV-at (P0^CL-at) and evaluated its role in Cbd-resistance break in cotton plants. It was demonstrated that P0^CL-at, despite having a mutation in the consensus of the F-box-like motif, was able to suppress local RNA silencing, but displayed lower activity than P0^CL. P0^CL and P0^CL-at showed no differences in the interaction with Gossypium hirsutum SKP1 orthologue (GSK1) and Nicotiana benthamiana SKP1 and both P0 proteins triggered destabilization of ARGONAUTE1. However, when the ability to enhance PVX symptoms was evaluated, P0^CL-at was shown to be a weaker pathogenicity factor than P0^CL in N. benthamiana. Interestingly, trans-expressed P0^CL-at enabled CLRDV to systemically infect CBD-resistant plants, and a chimeric CLRDV-P0^CL-at infectious clone succeeded in establishing infection in CBD-resistant cotton varieties with symptoms resembling those produced by CLRDV-at. These results strongly suggest that P0^CL-at is the avirulence (Avr) determinant involved in breaking cotton Cbd gene-based resistance.  相似文献   

Genetic differentiation between and within ecotypes of pike (Esox lucius) in the Baltic Sea     

Oscar Nordahl  Per Koch‐Schmidt  Johanna Sunde  Yeerin Y&#x;ld&#x;r&#x;m  Petter Tibblin  Anders Forsman  Per Larsson 《水产资源保护:海洋与淡水生态系统》2019,29(11):1923-1935

The future of fish passage science,engineering, and practice          下载免费PDF全文

Ana T. Silva  Martyn C. Lucas  Theodore Castro‐Santos  Christos Katopodis  Lee J. Baumgartner  Jason D. Thiem  Kim Aarestrup  Paulo S. Pompeu  Gordon C. O'Brien  Douglas C. Braun  Nicholas J. Burnett  David Z. Zhu  Hans‐Petter Fjeldstad  Torbjørn Forseth  Nallamuthu Rajaratnam  John G. Williams  Steven J. Cooke 《Fish and Fisheries》2018,19(2):340-362

Much effort has been devoted to developing, constructing and refining fish passage facilities to enable target species to pass barriers on fluvial systems, and yet, fishway science, engineering and practice remain imperfect. In this review, 17 experts from different fish passage research fields (i.e., biology, ecology, physiology, ecohydraulics, engineering) and from different continents (i.e., North and South America, Europe, Africa, Australia) identified knowledge gaps and provided a roadmap for research priorities and technical developments. Once dominated by an engineering‐focused approach, fishway science today involves a wide range of disciplines from fish behaviour to socioeconomics to complex modelling of passage prioritization options in river networks. River barrier impacts on fish migration and dispersal are currently better understood than historically, but basic ecological knowledge underpinning the need for effective fish passage in many regions of the world, including in biodiversity hotspots (e.g., equatorial Africa, South‐East Asia), remains largely unknown. Designing efficient fishways, with minimal passage delay and post‐passage impacts, requires adaptive management and continued innovation. While the use of fishways in river restoration demands a transition towards fish passage at the community scale, advances in selective fishways are also needed to manage invasive fish colonization. Because of the erroneous view in some literature and communities of practice that fish passage is largely a proven technology, improved international collaboration, information sharing, method standardization and multidisciplinary training are needed. Further development of regional expertise is needed in South America, Asia and Africa where hydropower dams are currently being planned and constructed.  相似文献   

Summary and Conclusions of the Joint EFSA‐EPPO Workshop on ‘Data collection and information sharing in plant health’*          下载免费PDF全文

AS Roy  F Petter  M Ward 《EPPO Bulletin》2015,45(2):257-258

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