602 research outputs found
High resolution mapping of Dense spike-ar (dsp.ar) to the genetic centromere of barley chromosome 7H
No full textSpike density in barley is under the control of several major genes, as documented previously by genetic analysis of a number of morphological mutants. One such class of mutants affects the rachis internode length leading to dense or compact spikes and the underlying genes were designated dense spike (dsp). We previously delimited two introgressed genomic segments on chromosome 3H (21 SNP loci, 35.5 cM) and 7H (17 SNP loci, 20.34 cM) in BW265, a BC(7)F(3) nearly isogenic line (NIL) of cv. Bowman as potentially containing the dense spike mutant locus dsp.ar, by genotyping 1,536 single nucleotide polymorphism (SNP) markers in both BW265 and its recurrent parent. Here, the gene was allocated by high-resolution bi-parental mapping to a 0.37 cM interval between markers SC57808 (Hv_SPL14)-CAPSK06413 residing on the short and long arm at the genetic centromere of chromosome 7H, respectively. This region putatively contains more than 800 genes as deduced by comparison with the collinear regions of barley, rice, sorghum and Brachypodium, Classical map-based isolation of the gene dsp.ar thus will be complicated due to the infavorable relationship of genetic to physical distances at the target locus.Fahimeh Shahinnia, Arnis Druka, Jerome Franckowiak, Michele Morgante, Robbie Waugh and Nils Stei
The International Barley Sequencing Consortium - At the Threshold of Efficient Access to the Barley Genome
Full text linkDaniela Schulte, Timothy J. Close, Andreas Graner, Peter Langridge, Takashi Matsumoto, Gary Muehlbauer, Kazuhiro Sato, Alan H. Schulman, Robbie Waugh, Roger P. Wise and Nils Stei
Robbie Burns Night
No full textPhotograph - A crowd at Robbie Burns night at Royal Canadian Legion, Athabasca Branch No. 103, Athabasca, Alberta. February 6, 196
Major chromosome 5H haplotype switch structures the European two-rowed spring barley germplasm of the past 190 years
Full text linkKey message: Selection over 70 years has led to almost complete fixation of a haplotype spanning ~ 250 Mbp of chomosome 5H in European two-rowed spring barleys, possibly originating from North Africa. Abstract: Plant breeding and selection have shaped the genetic composition of modern crops over the past decades and centuries and have led to great improvements in agronomic and quality traits. Knowledge of the genetic composition of breeding germplasm is essential to make informed decisions in breeding programs. In this study, we characterized the structure and composition of 209 barley cultivars representative of the European two-rowed spring barley germplasm of the past 190 years. Utilizing high-density SNP marker data, we identified a distinct centromeric haplotype spanning a ~ 250 Mbp large region on chromosome 5H which likely was first introduced into the European breeding germplasm in the early to mid-twentieth century and has been non-recombining and under strong positive selection over the past 70 years. Almost all cultivars in our panel that were released after 2000 carry this new haplotype, suggesting that this region carries one or several genes conferring highly beneficial traits. Using the global barley collection of the German Federal ex situ gene bank at IPK Gatersleben, we found the new haplotype at high frequencies in six-rowed spring-type landraces from Northern Africa, from which it may have been introduced into modern European barley germplasm via southern European landraces. The presence of a 250 Mbp genomic region characterized by lack of recombination and high levels of fixation in modern barley germplasm has substantial implications for the genetic diversity of the modern barley germplasm and for barley breeding.</p
Truth, purification and power: Foucault's genealogy of purity and impurity in and after The Will to Know lectures
No full textFoucault’s 1970–71 lectures at the Collège de France, The Will to Know, highlight the significance of themes of purity and impurity in Western thought. Reflecting on these themes coincided with the emergence of Foucault’s theory of power. This article presents the first analysis of Foucault’s investigation of purity and impurity in The Will to Know lectures, identifying the distinctive theory Foucault offers of purity as a discursive apparatus addressing correspondence between the subject and the truth through the image of relative integrity or mixture. It then traces Foucault’s subsequent reflections on these themes in his later writings on disciplinary power. The implications of Foucault’s position are considered; the article will close by putting Foucault’s ideas in dialogue with those of Kristeva, and in considering the role that purity and impurity may play in resistance
Genome wide association mapping for arabinoxylan content in a collection of tetraploid wheats
Full text linkBackground
Arabinoxylans (AXs) are major components of plant cell walls in bread wheat and are important in bread-making and starch extraction. Furthermore, arabinoxylans are components of soluble dietary fibre that has potential health-promoting effects in human nutrition. Despite their high value for human health, few studies have been carried out on the genetics of AX content in durum wheat.
Results
The genetic variability of AX content was investigated in a set of 104 tetraploid wheat genotypes and regions attributable to AX content were identified through a genome wide association study (GWAS). The amount of arabinoxylan, expressed as percentage (w/w) of the dry weight of the kernel, ranged from 1.8% to 5.5% with a mean value of 4.0%. The GWAS revealed a total of 37 significant marker-trait associations (MTA), identifying 19 quantitative trait loci (QTL) associated with AX content. The highest number of MTAs was identified on chromosome 5A (seven), where three QTL regions were associated with AX content, while the lowest number of MTAs was detected on chromosomes 2B and 4B, where only one MTA identified a single locus. Conservation of synteny between SNP marker sequences and the annotated genes and proteins in Brachypodium distachyon, Oryza sativa and Sorghum bicolor allowed the identification of nine QTL coincident with candidate genes. These included a glycosyl hydrolase GH35, which encodes Gal7 and a glucosyltransferase GT31 on chromosome 1A; a cluster of GT1 genes on chromosome 2B that includes TaUGT1 and cisZog1; a glycosyl hydrolase that encodes a CelC gene on chromosome 3A; Ugt12887 and TaUGT1 genes on chromosome 5A; a (1,3)-beta-D-glucan synthase (Gsl12 gene) and a glucosyl hydrolase (Cel8 gene) on chromosome 7A.
Conclusions
This study identifies significant MTAs for the AX content in the grain of tetraploid wheat genotypes. We propose that these may be used for molecular breeding of durum wheat varieties with higher soluble fibre content
Functional evaluation of RAMOSA2 cis-regulatory regions from different grass species for shaping inflorescence architecture in barley
Full text linkInflorescence architecture in grasses is considered one of the most important agronomic traits affecting crop yield. The inflorescence architecture is quite diverse, which includes branchless forms, such as the spike of barley and wheat, to more branched inflorescence, such as the panicle of sorghum. Identifying the genetic regulation of inflorescence developmental and molecular mechanisms behind the variation in inflorescence architecture is essential to increasing cereal crop yields. In the present study, to examine the effect of spatial-temporal activity of RA2 and its dosage on inflorescence architecture among barley, wheat, and sorghum, transgenic experiments were carried out by swapping RA2 promoters of different species fused with HvRA2 CDS and performing genetic complementation studies in branched barley ra2 mutant background and then quantifying recovery of canonical spike phenotypes.Die Blütenstandsarchitektur von Gräsern gilt als eines der wichtigsten agronomischen Merkmale, die den Ernteertrag beeinflussen. Die Blütenstandsarchitektur ist sehr vielfältig und umfasst verzweigte Formen wie die Ähre von Gerste und Weizen bis hin zu verzweigteren Blütenständen wie der Rispe von Sorghum. Die Identifizierung der genetischen Regulation der Blütenstandsentwicklung und der molekularen Mechanismen hinter der Variation in der Blütenstandsarchitektur ist für die Steigerung der Getreideerträge von wesentlicher Bedeutung. In der vorliegenden Studie wurden zur Untersuchung des Effektes der räumlich-zeitlichen Aktivität von RA2 und seiner Dosierung bei der Blütenstandarchitektur in Gerste, Weizen und Sorghum transgene Experimente durchgeführt, indem RA2-Promotoren verschiedener Arten, die mit HvRA2-CDS fusioniert waren, ausgetauscht und genetische Komplementationsstudien in verzweigtem Gersten-ra2 durchgeführtwurden Mutantenhintergrund und anschließende Quantifizierung der Wiederherstellung kanonischer Spike-Phänotypen
A guide to barley mutants
Full text linkBACKGROUND: Mutants have had a fundamental impact upon scientific and applied genetics. They have paved the way for the molecular and genomic era, and most of today's crop plants are derived from breeding programs involving mutagenic treatments.RESULTS: Barley (Hordeum vulgare L.) is one of the most widely grown cereals in the world and has a long history as a crop plant. Barley breeding started more than 100 years ago and large breeding programs have collected and generated a wide range of natural and induced mutants, which often were deposited in genebanks around the world. In recent years, an increased interest in genetic diversity has brought many historic mutants into focus because the collections are regarded as valuable resources for understanding the genetic control of barley biology and barley breeding. The increased interest has been fueled also by recent advances in genomic research, which provided new tools and possibilities to analyze and reveal the genetic diversity of mutant collections.CONCLUSION: Since detailed knowledge about phenotypic characters of the mutants is the key to success of genetic and genomic studies, we here provide a comprehensive description of mostly morphological barley mutants. The review is closely linked to the International Database for Barley Genes and Barley Genetic Stocks ( bgs.nordgen.org ) where further details and additional images of each mutant described in this review can be found.</p
Evolutionary relationships among barley and <i>Arabidopsis</i> core circadian clock and clock-associated genes
Full text linkThe circadian clock regulates a multitude of plant developmental and metabolic processes. In crop species, it contributes significantly to plant performance and productivity and to the adaptation and geographical range over which crops can be grown. To understand the clock in barley and how it relates to the components in the Arabidopsis thaliana clock, we have performed a systematic analysis of core circadian clock and clock-associated genes in barley, Arabidopsis and another eight species including tomato, potato, a range of monocotyledonous species and the moss, Physcomitrella patens. We have identified orthologues and paralogues of Arabidopsis genes which are conserved in all species, monocot/dicot differences, species-specific differences and variation in gene copy number (e.g. gene duplications among the various species). We propose that the common ancestor of barley and Arabidopsis had two-thirds of the key clock components identified in Arabidopsis prior to the separation of the monocot/dicot groups. After this separation, multiple independent gene duplication events took place in both monocot and dicot ancestors.</p
Tres Olas de Globalizacion: historia de una conciencia global (Alianz Enxayo) / Three Waves of Globalization: history of a global conscience (Spanish Edition)
No full text[Spanish] El concepto de globalización se considera algo bastante moderno pero según el autor de este libro, no es así. De hecho la humanidad ha experimentado tres diferentes oleadas de globalización en los últimos cinco siglos. Robbie Robertson hace una reinterpretación de la historia de la humanidad como un proceso de globalización creciente, que se ha acelerado en los últimos cinco siglos. Cada una de ellas ha cambiado el contexto en el que viven los humanos y la forma en que se ven a sí mismos y al mundo. En concreto, ha hecho posible el desarrollo de una conciencia global. Pero todavía es una conciencia débil y vulnerable y para entender la importancia de una conciencia global hay que contextualizar la globalización históricamente. Y eso es lo que hace el autor de este libro. Sobre todo conocer qué problemas internacionales, guerras o crisis económicas ha provocado cada ola de globalización y aprender las lecciones de la historia para analizar si la actual ola de globalización podría conducir en la misma dirección.
[English] The concept of globalization is considered quite modern but as the author of this book, it is not. In fact, humanity has experienced three distinct waves of globalization in the last five centuries. Robbie Robertson makes a reinterpretation of history as a process of increasing globalization, which has accelerated over the past five centuries. Each of them has changed the context in which humans live and how they view themselves and the world. Specifically, it has made possible the development of a global consciousness. But awareness is still weak and vulnerable and to understand the importance of global awareness should be historically contextualize globalization. And that is what the author of this book. Especially knowing what international problems, wars or economic crises caused each wave of globalization and learning the lessons of history to analyze whether the current wave of globalization could result in the same direction
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