Appearance of atypical Puccinia striiformis f. sp. tritici phenotypes in north-western Europe

2007 ◽  
Vol 58 (6) ◽  
pp. 518 ◽  
Author(s):  
Mogens S. Hovmøller ◽  
Annemarie F. Justesen
Keyword(s):  
Large Scale ◽  
Western Europe ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Time Period ◽  
Genetic Interpretation ◽  
Wide Range ◽  
Diverse Origin ◽  
Large Scale Cultivation ◽  
Short Time

A combination of large-scale cultivation of highly susceptible cultivars and mild winters caused severe yield losses due to yellow rust in NW Europe in the early 1990s, but in recent years the disease has become less predominant. Several atypical Puccinia striiformis f. sp. tritici pathotypes have been observed in recent years, showing virulence spectra which made them able only to infect cultivars covering less than 5% of the wheat and triticale area in Denmark. Some were even unable to grow on any of the standard ‘European’ and ‘World’ yellow rust differentials. We observed 2 distinct groups of atypical pathotypes, each subdividing into 2 highly divergent AFLP phenotypes. It was striking that AFLP diversity among unusual pathotypes, sampled within a short time period in a small area on very few host cultivars, which induced limited or no selection on the pathogen population, was 3–4 times higher than among isolates sampled from a large number of cultivars with different Yr-genes in 4 different countries during more than 25 years. The repeated occurrence of atypical phenotypes of diverse origin may suggest a more frequent and even more distant dispersal of P. striiformis uredospores than previously anticipated. Finally, the disease reactions conferred by these unusual types on a wide range of differentials were used to discuss the limits for a genetic interpretation in terms of assessment of virulence and avirulence in pathogen isolates.

scholarly journals Race Dynamics, Diversity, and Virulence Evolution in Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust in China from 2003 to 2007

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1093-1101 ◽  
Author(s):  
W. Q. Chen ◽  
L. R. Wu ◽  
T. G. Liu ◽  
S. C. Xu ◽  
S. L. Jin ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Large Scale ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Rust Fungus ◽  
Long Distance ◽  
Center Of Origin ◽  
Virulence Evolution ◽  
Large Scale Cultivation ◽  
Pathogen Populations

Stripe (or yellow) rust caused by Puccinia striiformis f. sp. tritici is the most destructive foliar disease of wheat in China. The pathogen populations were analyzed for virulence evolution, complexity, phenotypic dynamics, and diversity on temporal and spatial bases. A total of 41 races were identified and characterized from 4,714 stripe rust isolates collected during 2003 through 2007 from wheat growing areas in 15 provinces in China. The races were based on avirulence/virulence patterns to 19 differential host genotypes. Chinese stripe rust population exhibited high diversity with a complex virulence structure. Comparisons using the relative Shannon's index indicated that some differences in the richness and evenness of races were present in pathogen populations within years and between regions despite a national tendency to reduced diversity over time. A noticeably increased frequency of race CYR33 (Chinese yellow rust 33) with virulence for YrSu was the major virulence change recorded in this study compared to the results on an annual basis. Isolates of Puccinia striiformis f. sp. tritici from different regions showed differences in the composition of races, distribution frequency, and diversity. The uneven distribution of major races and comparatively greater diversity in the Northwest and Southwest regions than that in the Huang-Huai-Hai region suggest that long-distance migrations of the pathogen occur from one or more over-summering areas eastward into over-wintering areas. This supports the hypothesis that southern Gansu and northwestern Sichuan comprises a “center of origin for virulence”. Mutation of virulence or avirulence for host resistance in the stripe rust fungus may be the basic cause of the occurrence of new virulent types. The subsequent dominance of certain races will vary with parasitic fitness and the opportunities to be selected through large-scale cultivation of varieties with matching resistance genes. Implications of the center of origin for virulence variation and diversity in the pathogen population and an alternative strategy for limiting virulence evolution are discussed.

Towards Control of an Estuary

1987 ◽  
Vol 19 (9) ◽  
pp. 155-174
Author(s):  
Henk L. F. Saeijs
Keyword(s):  
Shallow Water ◽  
Storm Surge ◽  
Salt Marshes ◽  
Large Scale ◽  
Western Europe ◽  
Oxygen Depletion ◽  
Negative Effects ◽  
Intertidal Flats ◽  
Environmental Consequences ◽  
Short Time

The Delta Project is in its final stage. In 1974 it was subjected to political reconsideration, but it is scheduled now for completion in 1987. The final touches are being put to the storm-surge barrier and two compartment dams that divide the Oosterschelde into three areas: one tidal, one with reduced tide, and one a freshwater lake. Compartmentalization will result in 13% of channels, 45% of intertidal flats and 59% of salt marshes being lost. There is a net gain of 7% of shallow-water areas. Human interventions with large scale impacts are not new in the Oosterschelde but the large scale and short time in which these interventions are taking place are, as is the creation of a controlled tidal system. This article focusses on the area with reduced tide and compares resent day and expected characteristics. In this reduced tidal part salt marshes will extend by 30–70%; intertidal flats will erode to a lower level and at their edges, and the area of shallow water will increase by 47%. Biomass production on the intertidal flats will decrease, with consequences for crustaceans, fishes and birds. The maximum number of waders counted on one day and the number of ‘bird-days' will decrease drastically, with negative effects for the wader populations of western Europe. The net area with a hard substratum in the reduced tidal part has more than doubled. Channels will become shallower. Detritus import will not change significantly. Stratification and oxygen depletion will be rare and local. The operation of the storm-surge barrier and the closure strategy chosen are very important for the ecosystem. Two optional closure strategies can be followed without any additional environmental consequences. It was essential to determine a clearly defined plan of action for the whole area, and to make land-use choices from the outset. How this was done is briefly described.

Enterprise Crowdsourcing Platform to Improve HR Workflow

2020 ◽  
Vol 9 (5) ◽  
pp. 5-8 ◽  
Author(s):  
G. Zuev
Keyword(s):  
Large Scale ◽  
Best Practice ◽  
Cost Effective ◽  
Hr Management ◽  
Practical Project ◽  
Effective Manner ◽  
Wide Range ◽  
Hr Managers ◽  
Short Time ◽  
Small Parts

Crowdsourcing technologies may solve a wide range of business issues: improve efficiency of HR management, increase customer loyalty and maximize economic efficiency of whole enterprise. The recent years best practice has shown how crowdsourcing is gaining particular relevance of human resource management, allowing HR managers to resolve organization relevant problems in quick and cost-effective manner. Important advantage of crowdsourcing сomes from his main ability: decomposition of tasks into small parts and the ability to perform it’s remotely, via Internet. Thanks to this, not only large corporations, but also small and medium-sized businesses can execute a large-scale projects in a short time. This article discusses the main approaches and principles of practical project management via crowdsourcing platforms, using as the example “Beorg Smart Vision” solution.

scholarly journals Virulence Characterization of Puccinia striiformis f. sp. tritici Using a New Set of Yr Single-Gene Line Differentials in the United States in 2010

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1534-1542 ◽  
Author(s):  
Anmin Wan ◽  
Xianming Chen
Keyword(s):  
United States ◽  
Stripe Rust ◽  
Large Scale ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Single Gene ◽  
The United States ◽  
The Past ◽  
History Of

Puccinia striiformis f. sp. tritici causes stripe rust (yellow rust) of wheat and is highly variable in virulence toward wheat with race-specific resistance. During 2010, wheat stripe rust was the most widespread in the recorded history of the United States, resulting in large-scale application of fungicides and substantial yield loss. A new differential set with 18 yellow rust (Yr) single-gene lines was established and used to differentiate races of P. striiformis f. sp. tritici, which were named as race PSTv in distinction from the PST races identified in the past. An octal system was used to describe the virulence and avirulence patterns of the PSTv races. From 348 viable P. striiformis f. sp. tritici isolates recovered from a total of 381 wheat and grass stripe rust samples collected in 24 states, 41 races, named PSTv-1 to PSTv-41, were identified using the new set of 18 Yr single-gene differentials, and their equivalent PST race names were determined on the previous set of 20 wheat cultivar differentials. The frequencies and distributions of the races and their virulences were determined. The five most predominant races were PSTv-37 (34.5%), PSTv-11 (17.5%), PSTv-14 (7.2%), PSTv-36 (5.2%), and PSTv-34 (4.9%). PSTv-37 was distributed throughout the country while PSTv-11 and PSTv-14 were almost restricted to states west of the Rocky Mountains. The races had virulence to 0 to 13 of the 18 Yr genes. Frequencies of virulences toward resistance genes Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yr43, Yr44, YrTr1, and YrExp2 were high (67.0 to 93.7%); those to Yr1 (32.8%) and YrTye (31.3%) were moderate; and those to Yr10, Yr24, Yr32, and YrSP were low (3.4 to 5.7%). All of the isolates were avirulent to Yr5 and Yr15.

scholarly journals Biomass and Cordycepin Production by the Medicinal Mushroom Cordyceps militaris—A Review of Various Aspects and Recent Trends towards the Exploitation of a Valuable Fungus

2021 ◽  
Vol 7 (11) ◽  
pp. 986
Author(s):  
Dimitrios Kontogiannatos ◽  
Georgios Koutrotsios ◽  
Savvina Xekalaki ◽  
Georgios I. Zervakis
Keyword(s):  
Large Scale ◽  
Fruit Body ◽  
Cordyceps Militaris ◽  
Economic Losses ◽  
Ophiocordyceps Sinensis ◽  
Wide Range ◽  
Significant Research ◽  
Caterpillar Fungus ◽  
Recent Trends ◽  
Large Scale Cultivation

Cordyceps militaris is an entomopathogenic ascomycete with similar pharmacological importance to that of the wild caterpillar fungus Ophiocordyceps sinensis. C. militaris has attracted significant research and commercial interest due to its content in bioactive compounds beneficial to human health and the relative ease of cultivation under laboratory conditions. However, room for improvement exists in the commercial-scale cultivation of C. militaris and concerns issues principally related to appropriate strain selection, genetic degeneration of cultures, and substrate optimization. In particular, culture degeneration—usually expressed by abnormal fruit body formation and reduced sporulation—results in important economic losses and is holding back investors and potential growers (mainly in Western countries) from further developing this highly promising sector. In the present review, the main factors that influence the generation of biomass and metabolites (with emphasis on cordycepin biosynthesis) by C. militaris are presented and evaluated in conjunction with the use of a wide range of supplements or additives towards the enhancement of fungal productivity in large-scale cultivation processes. Moreover, physiological and genetic factors that increase or reduce the manifestation of strain degeneration in C. militaris are outlined. Finally, methodologies for developing protocols to be used in C. militaris functional biology studies are discussed.

scholarly journals COASTAL PROCESSES FROM SPACE PHOTOGRAPHY

1970 ◽  
Vol 1 (12) ◽  
pp. 39
Author(s):  
Maynard M. Nichols
Keyword(s):  
Large Scale ◽  
Salt Water ◽  
Remote Sensing Data ◽  
Vantage Point ◽  
Coastal Processes ◽  
Time Intervals ◽  
Wide Range ◽  
The World ◽  
Routine Basis ◽  
Short Time

Photographs taken from space provide a new source of data concerning coastal processes By utilizing the high vantage point and broad view orbiting space cameras can record little known large-scale processes at short time intervals Major outflow plumes, fresh-salt water "fronts", turbidity maxima and massive effluents are among the wide range of features displayed It is shown from selected examples how coastal processes can be evaluated from space photography and how the information may be of use for solving certain problems as a supplement to field and other remote sensing data By 1972 satellite photography will be available on a routine basis for many coasts of the world Engineers are urged to consider the potential for improving their information which space photography has to offer.

scholarly journals A Comprehensive Review on Biology, Genetic Improvement, Agro and Process Technology of German Chamomile (Matricaria chamomilla L.)

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 29
Author(s):  
Ramesh Chauhan ◽  
Sanatsujat Singh ◽  
Vikas Kumar ◽  
Ashok Kumar ◽  
Amit Kumari ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Large Scale ◽  
Process Development ◽  
Floral Biology ◽  
Oil Extraction ◽  
Plant Ecology ◽  
Soil Conditions ◽  
Process Technology ◽  
Wide Range ◽  
Large Scale Cultivation

German chamomile (M. chamomilla) is recognized as a star herb due to its medicinal and aromatic properties. This plant is found across a wide range of climatic and soil conditions. Both the flower heads and blue essential oils of German chamomile possess several pharmacological properties of an anti-inflammatory, antimicrobial, antiseptic, antispasmodic and sedative, etc., nature, which makes it a highly sought after herb for use in many pharma and aroma industries. Chamomile tea, prepared from its flower heads, is also a well-known herbal tea for mind and body relaxation. Though it is a high-demand herb, farmers have not adopted this plant for large scale cultivation as a crop, which could improve their livelihood, due to the high cost in flower heads harvesting, loss in over mature and immature flower heads picking during harvesting, unavailability of varieties and agrotechnologies for machine harvesting, a lack of efficient process development of oil extraction and in the lack of improved stable varieties. There are many studies that have reported on the phytochemistry and pharmacological uses of chamomile, which further explore its importance in the medicine industry. Several studies are also present in the literature on its cultivation practices and plant ecology. However, studies on breeding behavior, genetic improvement, varietal development and mechanical harvesting are scarce in German chamomile. Hence, keeping in mind various aspects of farmers’ and researchers’ interest, earlier reports on taxonomy, floral biology, processing of oil extraction, active constituents, uses, agronomy, breeding challenges and opportunities in German chamomile are summarized in this review.

Physiographic controls on pre-event hydrological states and hydrological response to extreme precipitation in the Alzette River Basin, Luxembourg

2020 ◽  
Author(s):  
Carol Tamez-Melendez ◽  
Judith Meyer ◽  
Audrey Douinot ◽  
Günter Blöschl ◽  
Laurent Pfister
Keyword(s):  
Land Use ◽  
River Basin ◽  
Urban Areas ◽  
Large Scale ◽  
Western Europe ◽  
Flash Flood ◽  
Potential Evapotranspiration ◽  
Hydrological Regime ◽  
Area Of Interest ◽  
Wide Range

<p>The hydrological regime of rivers in Luxembourg (Central Western Europe) is characterised by summer low flows and winter high flows. In winter, large-scale floods are typically triggered by long-lasting sequences of precipitation events, related to westerly atmospheric fluxes that carry wet and temperate air masses from the Atlantic Ocean. In recent years, several flash flood events have been observed in Luxembourg. While being a common feature of Mediterranean river basins, this type of flooding events is uncommon at higher latitudes. The design of the hydro-meteorological monitoring and forecasting systems operated in Luxembourg is not adapted to this type of extreme events and there is a pressing need for a better mechanistic understanding of flash flood triggering mechanisms.</p><p>Here, we explore two lines of research – focusing on (i) the spatio-temporal variability of flash flood generation across a set of 41 nested catchments covering a wide range of physiographic settings (with mixed land use, soil types and bedrock geology) and (ii) the responsivity (resistance) and elasticity (resilience) of these catchments to global change.</p><p>Our area of interest is the Sûre River basin (4,240 km<sup>2</sup>), characterised by a homogenous climate (temperate oceanic), as well as various bedrock (e.g. sandstone, marls, shale) and land use (e.g. forests, grassland, crops, urban areas) types. Based on 8 years’ worth of daily hydrological data (precipitation, discharge and potential evapotranspiration) we computed the increments of the water balance to determine the maximum storage capacity and pre-event wetness state (expressed as storage deficit). Based on the relationship between storage deficit and discharge we first estimated total storage at nearly zero flow conditions. Second, we compared event runoff ratios (Q/P) to pre-hydrological states (as expressed to storage deficit prior to a rainfall-runoff event) in order to assess each catchment’s sensitivity to antecedent wetness conditions. Third, we assessed the responsivity (resistance) and elasticity (resilience) to climate variations – as expressed through the PET/P and AET/P deviations from the Budyko curve – for each individual catchment. Finally, we investigated potential physiographic controls on catchment responsivity and elasticity across our set of 41 nested catchments.</p>

Study on Technology System and System Integration Method of China High-Speed Railway

2010 ◽  
Author(s):  
Shuguang Zhang
Keyword(s):  
System Integration ◽  
High Speed ◽  
Large Scale ◽  
Integration Method ◽  
Low Cost ◽  
Short Time Period ◽  
High Speed Railway ◽  
Technology System ◽  
Time Period ◽  
Short Time

Since 2004, China had launched the construction of a large-scale high-speed railways network, China had developed a set of mature, reliable technology systems and system integration method for high-speed railways with relatively low cost in a comparatively short time period. The special demands for highspeed railways in china were analyzed firstly, and then the structure and characteristics of the technology system of China high-speed railways were presented, as well as the system integration method. At last, the development trends of China high-speed railway technology are proposed.

scholarly journals Methodology for Bathymetric Mapping Using Open-Source Software

2020 ◽  
Vol 24 (3) ◽  
pp. 239-248
Author(s):  
Jānis Dumpis ◽  
Ainis Lagzdiņš
Keyword(s):  
Open Source ◽  
Open Source Software ◽  
High Definition ◽  
Bathymetric Survey ◽  
Depth Data ◽  
Time Period ◽  
Wide Range ◽  
Computer Environment ◽  
Bathymetric Map ◽  
Short Time

AbstractThe modern technologies not only provide an opportunity to collect water depth data much more efficiently than in the past, but also there is a wide range of opportunities to process these data to develop bathymetric maps and perform various calculations in the computer environment. This research aims to construct a high-resolution bathymetric map by using open-source software. Lake Zebrus was selected as the study site, where fieldwork was performed to obtain the depth data and subsequently process to find optimal methodology for creating a bathymetric map. The methodology used in this research is modifiable for different purposes and is based on obtaining the best results from using open-source resources and knowledge of cartography. Lake Zebrus is an example how to perform accurate and state of the art bathymetric survey in a short time period. The area of Lake Zebrus is 417.57 ha. The lake has a small crooked coastline. Lake Zebrus has a maximum depth of 4.45 m and an average depth of 1.48 m. Results from the bathymetric survey can be used for further research based on depth data. The research tasks are accomplished as the methodology selected is repeatable in the other lakes. The research results prove that this methodology can be used for a bathymetric survey and it is possible to obtain high-definition results using open-source resources.

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