scholarly journals Spatial and Temporal Abundance of Interacting Populations of White Clover and Grass Species as Assessed by Image Analyses

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anne Kjersti Bakken ◽  
Helge Bonesmo ◽  
Bård Pedersen
Keyword(s):  
White Clover ◽  
Spatial Dynamics ◽  
Grass Species ◽  
Plant Interactions ◽  
Wide Range ◽  
Interacting Populations ◽  
Spatial Configurations ◽  
Experimental Treatments ◽  
Further Development ◽  
Local Nature

The dataset comprises detailed mappings of two communities of interacting populations of white clover (Trifolium repens L.) and grass species under differing experimental treatments over 4-5 years. Information from digital photographs acquired two times per season has been processed into gridded data and documents the temporal and spatial dynamics of the species that followed from a wide range of spatial configurations that arose during the study period. The data contribute a unique basis for validation and further development of previously published models for the dynamics and population oscillations in grass-white clover swards. They will be well suited for estimating parameters in spatially explicit versions of these models, like neighborhood based models that incorporate both the dispersal and the local nature of plant-plant interactions.

The yields of barley following leys based on different grass species

1965 ◽  
Vol 64 (1) ◽  
pp. 3-9
Author(s):  
John L. Hammerton ◽  
R. S. Edwards
Keyword(s):  
White Clover ◽  
Crude Protein ◽  
Dry Matter ◽  
Fertilizer Application ◽  
Grass Species ◽  
Yield Data ◽  
Management Regime ◽  
Experimental Area ◽  
Compound Fertilizer ◽  
Experimental Treatments

In two earlier papers (Henderson, Edwards & Hammerton, 1962a, b) data on the yields of dry matter and crude protein obtained in an experiment carried out at Aberystwyth over the period 1954–56 were presented. The experiment compared the productivity of five leys, each based on a single grass species with white clover, at six levels of compound fertilizer, under a management regime of three cuts per annum. Subsequent to 1956 the fertilizer application and cutting regime were continued, but no yield data were collected. Early in 1960, the experimental area was ploughed up and sown to barley, in order to study the effects of the previous experimental treatments on arable productivity. Barley was also sown in 1961 and 1962, and the present paper is concerned with the yields of the three successive crops of barley.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

USE OF CELL AND MOLECULAR GENETIC MANIPULATION TO IMPROVE PASTURE PLANTS

1988 ◽  
pp. 67-72
Author(s):  
D.W.R. White
Keyword(s):  
Cell Culture ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Nutritional Quality ◽  
Rust Resistance ◽  
Herbicide Tolerance ◽  
Pest Resistance ◽  
Crown Rust ◽  
Wide Range ◽  
Pasture Plants

Cell culture and genetic engineering techniques can be used to develop improved pasture plants. To utilise these methods we have developed procedures for regenerating plants from tissue cultures of perennial ryegrass and white clover. In both, the plant genotype influences regeneration capacity. There was significant genetic variation among regenerated perennial ryegrass plants in a wide range of characteristics. Most of the regenerants were resIstant to crown rust and this trait was highly heritable. This rust resistance is being used to breed a new ryegrass cultivar. A system for introducing cloned genes into white clover is described. This capability is bemg used to incorporate genes with the potential to improve nutritional quality and pest resistance. Other possibilities for engineering genetic improvements in white clover, genes conferring herbicide tolerance and resistance to white clover mosaic virus, are briefly outlined. Keywords: Lolium perenne, Trifolium repens, cell culture, somaclonal variation, crown rust resistance, transformation, cloned genes, nutritional quality, proteinase inhibitors, Bt toxins, pest resistance, WCMV viral cross-protection, herbicide tolerance, Agrobacterium, Bacillus thuringenisis.

Theoretical Ecology

2007 ◽  
Keyword(s):  
Spatial Dynamics ◽  
Theory And Practice ◽  
The Novel ◽  
Basic Principles ◽  
Theoretical Ecology ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Interacting Populations ◽  
Novel Material ◽  
Ecological Science

Robert May's seminal book has played a central role in the development of ecological science. Originally published in 1976, this influential text has overseen the transition of ecology from an observational and descriptive subject to one with a solid conceptual core. Indeed, it is a testament to its influence that a great deal of the novel material presented in the earlier editions has now been incorporated into standard undergraduate textbooks. It is now a quarter of a century since the publication of the second edition, and a thorough revision is timely. Theoretical Ecology provides a succinct, up-to-date overview of the field set in the context of applications, thereby bridging the traditional division of theory and practice. It describes the recent advances in our understanding of how interacting populations of plants and animals change over time and space, in response to natural or human-created disturbance. In an integrated way, initial chapters give an account of the basic principles governing the structure, function, and temporal and spatial dynamics of populations and communities of plants and animals. Later chapters outline applications of these ideas to practical issues including fisheries, infectious diseases, tomorrow's food supplies, climate change, and conservation biology. Throughout the book, emphasis is placed on questions which as yet remain unanswered. The editors have invited the top scientists in the field to collaborate with the next generation of theoretical ecologists. The result is an accessible, advanced textbook suitable for senior undergraduate and graduate level students as well as researchers in the fields of ecology, mathematical biology, environmental and resources management. It will also be of interest to the general reader seeking a better understanding of a range of global environmental problems.

Use of tall fescue EST-SSR markers in phylogenetic analysis of cool-season forage grasses

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 637-647 ◽  
Author(s):  
M A. Rouf Mian ◽  
Malay C Saha ◽  
Andrew A Hopkins ◽  
Zeng-Yu Wang
Keyword(s):  
Phylogenetic Analysis ◽  
Ssr Markers ◽  
Tall Fescue ◽  
Related Species ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Grasses ◽  
Cool Season ◽  
Phylogenetic Relations ◽  
Wide Range

Microsatellites or simple sequence repeats (SSRs) are highly useful molecular markers for plant improvement. Expressed sequence tag (EST)-SSR markers have a higher rate of transferability across species than genomic SSR markers and are thus well suited for application in cross-species phylogenetic studies. Our objectives were to examine the amplification of tall fescue EST-SSR markers in 12 grass species representing 8 genera of 4 tribes from 2 subfamilies of Poaceae and the applicability of these markers for phylogenetic analysis of grass species. About 43% of the 145 EST-SSR primer pairs produced PCR bands in all 12 grass species and had high levels of polymorphism in all forage grasses studied. Thus, these markers will be useful in a variety of forage grass species, including the ones tested in this study. SSR marker data were useful in grouping genotypes within each species. Lolium temulentum, a potential model species for cool-season forage grasses, showed a close relation with the major Festuca–Lolium species in the study. Tall wheatgrass was found to be closely related to hexaploid wheat, thereby confirming the known taxonomic relations between these species. While clustering of closely related species was found, the effectiveness of such data in evaluating distantly related species needs further investigations. The phylogenetic trees based on DNA sequences of selected SSR bands were in agreement with the phylogenetic relations based on length polymorphism of SSRs markers. Tall fescue EST-SSR markers depicted phylogenetic relations among a wide range of cool-season forage grass species and thus are an important resource for researchers working with such grass species.Key words: phylogeny, EST-SSR, forage grasses, tall fescue.

scholarly journals Multiple cellular compartments engagement in Nicotiana benthamiana-peanut stunt virus-satRNA interactions revealed by systems biology approach

2021 ◽  
Author(s):  
Barbara Wrzesińska ◽  
Agnieszka Zmienko ◽  
Lam Dai Vu ◽  
Ive De Smet ◽  
Aleksandra Obrępalska-Stęplowska
Keyword(s):  
Virus Infection ◽  
Nicotiana Benthamiana ◽  
Cellular Localization ◽  
Plant Interactions ◽  
Satellite Rna ◽  
Functional Connections ◽  
Cell Compartments ◽  
Wide Range ◽  
Peanut Stunt Virus ◽  
Cellular Compartments

Abstract Key message PSV infection changed the abundance of host plant’s transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and cytosol, affecting photosynthesis, translation, transcription, and splicing. Abstract Virus infection is a process resulting in numerous molecular, cellular, and physiological changes, a wide range of which can be analyzed due to development of many high-throughput techniques. Plant RNA viruses are known to replicate in the cytoplasm; however, the roles of chloroplasts and other cellular structures in the viral replication cycle and in plant antiviral defense have been recently emphasized. Therefore, the aim of this study was to analyze the small RNAs, transcripts, proteins, and phosphoproteins affected during peanut stunt virus strain P (PSV-P)–Nicotiana benthamiana interactions with or without satellite RNA (satRNA) in the context of their cellular localization or functional connections with particular cellular compartments to elucidate the compartments most affected during pathogenesis at the early stages of infection. Moreover, the processes associated with particular cell compartments were determined. The ‘omic’ results were subjected to comparative data analyses. Transcriptomic and small RNA (sRNA)–seq data were obtained to provide new insights into PSV-P–satRNA–plant interactions, whereas previously obtained proteomic and phosphoproteomic data were used to broaden the analysis to terms associated with cellular compartments affected by virus infection. Based on the collected results, infection with PSV-P contributed to changes in the abundance of transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and the cytosol, and the most affected processes were photosynthesis, translation, transcription, and mRNA splicing. Furthermore, sRNA-seq and phosphoproteomic analyses indicated that kinase regulation resulted in decreases in phosphorylation levels. The kinases were associated with the membrane, cytoplasm, and nucleus components.

The functions and positions of political parties in consociational democracies: theoretical and empirical contexts

2020 ◽  
pp. 28-33
Author(s):  
O. Morhuniuk
Keyword(s):  
Political Parties ◽  
The Netherlands ◽  
Party System ◽  
Party Competition ◽  
European Countries ◽  
The Past ◽  
Democratic Regimes ◽  
Wide Range ◽  
Key Aspects ◽  
Further Development

An article is devoted to the analysis of the functions and formats of political parties in consociational democracies. In particular, it is defined that parties that represent the interests of certain subcultures in society and that reach a consensus among themselves at the level of political agreements are called segmental. At the same time, parties that encapsulate different subgroups of the society that cooperate inside the party within main features of the consociational theory (grand coalition, mutual veto, proportionality in representations, and independence of segments or society subcultures) are called consociational. The theory of consociationalism has received a wide range of theoretical additions and criticism from political scientists over the past fifty years. And while political parties should have been, by definition, one of the key aspects of research within such democratic regimes (parties are part of large coalitions and agents of representation of certain subcultures), there is very scarce number of literature that focuses on this aspect. Therefore, the presented article provides a description of the functions of political parties that could be observed as inside their subcultures as well as in interaction with other segmental parties. Based on the experience of two European countries in the period of “classical” consociationalism (Belgium and the Netherlands), we explain the functions of the parties we have defined in such societies with examples of relevant consociational practices in them. Simultaneously with the analysis of segmental parties, the article also offers the characteristics of consociational parties. The emergence of such parties has its own institutional and historical features. The way of further development of the party system and the level of preservation of consociational practices makes it possible to understand the nature of changes in the societies. Similarly, the analysis of the forms of party competition and interaction between segmental parties makes it possible to outline the forms of those consociational changes that are taking place in the research countries.

Third generation progress in breeding white clover for resistance to root-knot nematode

1996 ◽  
Vol 6 ◽  
pp. 163-166
Author(s):  
J. Van den Bosch ◽  
C.F. Mercer
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Egg Production ◽  
Control Method ◽  
Dry Weight ◽  
Third Generation ◽  
Root Knot Nematode ◽  
Root Dry Weight ◽  
Wide Range ◽  
Meloidogyne Sp

Root-knot nematode (Meloidogyne sp.) reduces growth and nutrition of white clover (Trifolium repens L.) in New Zealand, and breeding resistant cultivars (with low galls per gram of root) is the preferred control method. Resistant and susceptible selections were bred from a wide range of white clover lines for three generations. In the third generation there were significant differences between seed lines from the selections for number of galls, root dry weight, visual growth score and galls/gram of root dry weight. Resistant selections had 43% of the susceptible selections' galls per gram, and 50% of the number of galls. Germplasm showing resistance to Meloidogyne spp. in the USA showed partial resistance to the local Meloidogyne sp. Two resistant and two susceptible genotypes were also compared for nematode egg production; resistant genotypes had a mean of 3,460 eggs/plant, compared to 25,030 for susceptible genotypes. Keywords: breeding, Meloidogyne sp., resistance, rootknot nematode, screening, selection, Trifolium repens, white clover

Urochloa platyphylla (broadleaf signalgrass).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Environmental Conditions ◽  
Crop Residue ◽  
Soil Surface ◽  
Grass Species ◽  
Crop Fields ◽  
Wide Range ◽  
Germinating Seeds

Abstract U. platyphylla is a weedy grass species commonly found in disturbed, open and sandy sites such as crop fields, ditches and roadsides. It is considered a troublesome weed because of its tolerance to some herbicides principally in maize plantations (Chamblee et al., 1982; Gallaher et al.,1999). U. platyphylla is highly adaptable and it is able to germinate and grow throughout a wide range of soil and environmental conditions (Burke et al., 2003). Additionally, its seeds may remain on the crop residue until pre-emergence herbicides are no longer effective in controlling the germinating seeds, at which time the seeds fall to the soil surface and germinate (Alford et al., 2005).

scholarly journals Cloning and Mapping of a Putative Barley NADPH-Dependent HC-Toxin Reductase

1997 ◽  
Vol 10 (2) ◽  
pp. 234-239 ◽  
Author(s):  
F. Han ◽  
A. Kleinhofs ◽  
A. Kilian ◽  
S. E. Ullrich
Keyword(s):  
Plant Species ◽  
Chromosome 9 ◽  
Immature Embryos ◽  
Chromosome 1 ◽  
Grass Species ◽  
Cochliobolus Carbonum ◽  
Wide Range ◽  
Young Leaves ◽  
High Conservation ◽  
Hc Toxin

The NADPH-dependent HC-toxin reductase (HCTR), encoded by Hm1 in maize, inactivates HC-toxin produced by the fungus Cochliobolus carbonum, and thus confers resistance to the pathogen. The fact that C. carbonum only infects maize (Zea mays) and is the only species known to produce HC-toxin raises the question: What are the biological functions of HCTR in other plant species? An HCTR-like enzyme may function to detoxify toxins produced by pathogens which infect other plant species (R. B. Meeley, G. S. Johal, S. E. Briggs, and J. D. Walton, Plant Cell, 4:71–77, 1992). Hm1 homolog in rice (Y. Hihara, M. Umeda, C. Hara, Q. Liu, S. Aotsuka, K. Toriyama, and H. Uchimiya, unpublished) and HCTR activity in barley, wheat, oats and sorghum have been reported (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080–1086, 1993). To investigate the sequence conservation of Hm1 and HCTR in barley and the possible relationship of barley Hm1 homolog to the known disease resistance genes, we cloned and mapped a barley (Hordeum vulgare) Hm1-like gene. A putative full-length cDNA clone, Bhm1-18, was isolated from a cDNA library consisting of mRNA from young leaves, inflorescences, and immature embryos. This 1,297-bp clone encodes 363 amino acids which show great similarity (81.6%) with the amino acid sequence of HM1 in maize. Two loci were mapped to barley molecular marker linkage maps with Bhm1-18 as the probe; locus A (Bhm1A) on the long arm of chromosome 1, and locus B (Bhm1B) on the short arm of chromosome 1 which is syntenic to maize chromosome 9 containing the Hm2 locus. The Bhm1-18 probe hybridized strongly to a Southern blot of a wide range of grass species, indicating high conservation of HCTR at the DNA sequence level among grasses. The HCTR mRNA was detected in barley roots, leaves, inflorescences, and immature embryos. The conservation of the HCTR sequence, together with its expression in other plant species (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080–1086, 1993), suggests HCTR plays an important functional role in other plant species.

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