1,720,966 research outputs found
A method for obtaining flexible broccoli varieties for sustainable agriculture
No full textBackground: The use of high inputs in agriculture resulted in few varieties (hybrids and pure lines) used in all agricultural systems. Also varieties of vegetables, including broccoli, for organic and low-input agriculture, are almost exclusively hybrids, since there are very few specific breeding programs and varieties for sustainable agriculture systems.A strategy to overcome this issue is the adoption of specific breeding programs for developing heterogeneous varieties (i.e. synthetics, open pollinated varieties, composite cross populations and mixtures). In fact, heterogeneous varieties are able to evolve and adapt to specific agro-climatic conditions.The aim of this study was to develop a method (an Evolutionary Breeding Program, EBP) for obtaining heterogeneous varieties of broccoli and test its efficiency in developing highly diverse varieties, as needed in sustainable agriculture.A synthetic variety originated from a landrace was multiplied in different environments for 3 cycles and morpho-phenological and genetic diversity of the derived populations were assessed.Results: The presented results are the first and unique indication about the efficiency of a short-time EBP for an allogamous species like broccoli.Few morphological changes were observed among varieties multiplied in different environments with different agro-climatic conditions. This could be probably due to the initial genetic diversity of the landrace from which the populations were selected and also to the great plasticity of the crop. However, SSR data highlighted a genetic differentiation among populations multiplied for two/three years across Europe and in Central Italy, that was not so evident when considering morphological data only.Conclusions: Few years of multiplication in different environments resulted in genetically differentiated broccoli populations that nonetheless preserved the original genetic diversity and productivity level and appear to evolve in relationship to different environments: the applied EBP is useful for developing heterogeneous materials for sustainable agriculture
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
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
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
Investigating the genetic basis of salt-tolerance in common bean: a genome-wide association study at the early vegetative stage
Full text linkSalinity poses a significant challenge to global crop productivity, affecting approximately 20% of cultivated and 33% of irrigated farmland, and this issue is on the rise. Negative impact of salinity on plant development and metabolism leads to physiological and morphological alterations mainly due to high ion concentration in tissues and the reduced water and nutrients uptake. Common bean (Phaseolus vulgaris L.), a staple food crop accounting for a substantial portion of consumed grain legumes worldwide, is highly susceptible to salt stress resulting in noticeable reduction in dry matter gain in roots and shoots even at low salt concentrations. In this study we screened a common bean panel of diversity encompassing 192 homozygous genotypes for salt tolerance at seedling stage. Phenotypic data were leveraged to identify genomic regions involved in salt stress tolerance in the species through GWAS. We detected seven significant associations between shoot dry weight and SNP markers. The candidate genes, in linkage with the regions associated to salt tolerance or harbouring the detected SNP, showed strong homology with genes known to be involved in salt tolerance in Arabidopsis. Our findings provide valuable insights onto the genetic control of salt tolerance in common bean and represent a first contribution to address the challenge of salinity-induced yield losses in this species and poses the ground to eventually breed salt tolerant common bean varieties
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Drafting a prioritized checklist of Crop Wild Relatives and Wild Harvested Plants of Italy: problems and solutions
Full text linkThe National checklists of Crop Wild Relatives (CWR) and Wild Harvested Plants (WHP) are the basic tools for the development of in situ and ex situ conservation strategies of plant genetic resources. Here we discuss the methodologies and the prioritization process we previously used in the preparation of the prioritized checklist of CWR and WHP for Italy.
The starting point were the most up-to-date Italian checklists of native and alien flora with their updates used as a nomenclatural and distributive source of data. Sardinia and Sicily were kept separate from peninsular Italy to perform detailed analyses focused on the taxa of the two major islands. The origin, the endemic status, cultivation, economic importance, uses, gene pool or taxon group, and the Red List status information were added. The WHP status was attributed to all the taxa with known direct uses. A qualitative approach was adopted in the prioritization
process, the main criteria used were: 1) the inclusion of wild relative taxa of crops listed in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) and/or by the Italian Institute of Statistics (ISTAT) for cultivated areas and yield in the last 5 years; 2) the threatened taxa occurring in national or global Red lists; 3) the endemism.
This prioritization process generated 102 taxa as most in need of specific protection and /or monitoring measures, 57 taxa requiring monitoring because of their restricted distribution although not requiring specific protection measures and 735 taxa not requiring any specific protection. However, different prioritization processes could have been applied to the Italian checklists yielding different results. Here we discuss the matter
A new list and prioritization of wild plants of socioeconomic interest in Italy: toward a conservation strategy
No full textWild harvested plants (WHP) and crop wild relatives (CWR), part of the segment of natural diversity that is collectively known as ‘Plant Genetic Resources’, have great socioeconomic importance for humans because they are used either directly or in crop breeding. In order to lay down a solid base for constructing conservation strategies for Italy, an updated annotated list of CWR and WHP was produced for the country including information on known uses. Taxa included in the list were then prioritized using a pragmatic approach based on their value, native status, and need of protection or monitoring
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