1,721,718 research outputs found
Combining Mutant Analysis and Genome Wide Association for Root Genetics Dissection in Barley
No full textKnowledge about the genetic control of root development and architecture is lagging behind others plant traits and functions. This is negatively impacting modern plant breeding addressing drought tolerance and nutrient use efficiency. In this study, we investigated the genetic control of barley root architecture by exploring both induced and native genetic variation. We screened the barley TILLMore mutagenized population to identify root architecture mutants at seedling stages (2 weeks) using a semi-hydroponic system. We identified approx. 40 mutant lines, which grouped in three categories: root growth rate/length (short and long, 77%), root morphology (coiling or geotropic, 15%) and root hairs (hairless or shorthairs, 8%). Several mutants were tested for Mendelian inheritance and confirmed. SNP-based bulk-segregant analysis combined with exome and/or whole-genome shotgun sequencing enabled us to identify root candidate genes. Using the same root phenotyping protocol, a collection of >400 barley landraces and cultivars was phenotyped and GWA was carried out taking advantage of exome-seq based SNP analysis. Interestingly, the mutant loci and GWA-based QTL showed little if any overlaps, suggesting the presence of a largely undiscovered genetic system controlling root architecture in barley
ALMA-ARUNDO: nuovi cloni di Arundo donax per produzione di biometano
No full textLa produzione di energia di fonti rinnovabili è oggi una dei principali fattori capaci di rendere più sostenibile un sistema economico.
Tra le diverse filiere, la digestione anaerobica di prodotti lignino-cellulosici per la produzione di biogas e/o biometano, è uno dei
sistemi più efficaci. Arundo donax (Arundo nel seguito) è la più efficiente specie vegetale nella produzione di biomassa nei nostri
ambienti. Il DIPSA ha prodotto la prima collezione di mutanti di Arundo (> 1.000 cloni), allo scopo di allargare la base genetica della
specie e favorire la selezione di nuove varietà più performanti dal punto di vista produttivo e di metanificazione. In questo progetto
(ALMA-ARUNDO), ci prefiggiamo di caratterizzare la struttura del genoma, le caratteristiche morfo-fisiologiche, del metabolismo dei
carboidrati e la resa in metano di una selezione di cloni di Arundo. Obiettivi finale è l’identificazione di cloni di potenziale interesse
commercial
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparative analysis of genetic relationships in barley based on RFLP and RAPD markers
No full textGenetic relationships have seldom been analyzed with different types of molecular markers in order to compare the information provided by each marker class. We investigated genetic relationships among nine barley cultivars using separate cluster analyses based on restriction fragment length polymorphisms (RFLPs) and random amplified polymorphic DNAs (RAPDs). Genomic DNA restricted with three enzymes and hybridized with 68 probes revealed 415 RFLPs (74.2% of all bands). Among the 128 primers used for RAPD analysis, 100 provided a reproducible profile, 89 of which revealed 202 polymorphic and 561 monomorphic bands (26.5 and 73.5%, respectively). A nonrandom distribution of 62 RAPDs with a tendency to cluster near centromeric regions was produced when these RAPDs were mapped using 76 doubled-haploid lines derived from a cross between two of the nine cultivars. The correlation between the RFLP and RAPD similarity matrices computed for the 36 pairwise comparisons among the nine cultivars was equal to 0.83. The dendrograms obtained by cluster analyses of the RFLP and RAPD data differed. These results indicate that in barley the information provided by RFLPs and RAPDs is not equivalent, most likely as a consequence of the fact that the two marker classes explore, at least in part, different portions of the genome
Assessment of mutagenized giant reed clones for yield, drought resistance and biomass quality
No full textGiven the sterility of giant reed (Arundo donax L.), mutagenesis can be a valid strategy to increase genetic diversity in the species and to enable the selection of superior genotypes with new agronomic and qualitative characteristics. The objective of this study was to evaluate the quantitative and qualitative traits of selected three-year old giant reed mutants (UniBO3; Line10; and Line11). The mutants' performance was evaluated in comparison to the local non-mutagenized ecotype (Arun11) under irrigated and rainfed conditions. Yield differences among mutants were significant: Line11 produced the highest (24 Mg ha−1), and UniBO3 the lowest (19 Mg ha−1) biomass yield, while Line10 showed intermediate yield (22 Mg ha−1). Such variable yields were in line with tiller density and WUE. Besides that, Line11 showed and enhanced plasticity in its water uptake sources and drought resistance. However, the effects of the irrigation and the genotype by irrigation treatment interaction were not significant. The irrigation treatment did not change either the qualitative characteristics of Line11: the cellulose content (42%) was higher than in the control and UniBO3 mutant. Whereas the hemicellulose and lignin contents remained unvaried, suggesting Line11 as a promising feedstock for conversion to advanced biofuels. As for the mineral composition, Line11 showed the most marked changes, especially in terms of K, Si, and Si/K ratio, suggesting a lowered quality for thermochemical conversion. The induced variability shows some promising characteristics that could lead to new specialized mutant lines with improved suitability to specific environmental conditions and conversion technologies
Development of PCR-based assays for allelic discrimination in maize by using the 5′-nuclease procedure
No full textWe describe the development of non-electrophoresis-based PCR assays for the allelic discrimination at two linked loci flanking an important QTL controlling days to pollen shed in maize. The assays are based on the fluorogenic 5′-nuclease procedure (TaqMan), which allows for the direct detection of the PCR product by the release of a fluorescent reporter dye as a result of DNA amplification. The assays were developed after sequencing the alleles at both loci, by designing suitable primers and probes based on single nucleotide or insertion/deletion polymorphisms. The TaqMan procedure allowed for a fast and highly reproducible analysis directly in the PCR vials. The lack of any fragment separation step allows for an almost complete automation of the process thus making this technique particularly valuable for the large-scale screening required for map-based cloning projects and for marker-assisted selection, particularly when the results are needed in a short time
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
ICP-MS Triplo Quadrupolo come tecnica analitica per la definizione dell'impronta in traccia e ultra-traccia di olio extravergine di oliva
Full text linkL'olio extravergine di oliva è un prodotto tipico dell'area mediterranea e la tutela della sua origine viene continuamente monitorata. In questo lavoro di ricerca è stata messa a punto la metodologia per analizzare campioni di olio extra vergine di olive con lo spettrometro di massa triplo quadrupolo, installato presso il Laboratorio Tracciabilità (FSN-SICNUC-TNMT) del Brasimone. Per individuare la metodologia di preparazione dei campioni ottimale, sono stati analizzati 24 campioni di olio d'oliva di diversa provenienza geografica (Rizzo et al., 2019), i cui risultati in ICP-MS-QQQ sono poi stati elaborati con tecniche chemiometriche per determinare l'affidabilità del metodo
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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