1,720,973 research outputs found
Genotyping-by-Sequencing Defines Genetic Structure within the “Acquaviva” Red Onion Landrace.
No full textLandraces of horticultural species represent unvaluable sources of
agrobiodiversity, which can be employed in cultivation as such, or used in
breeding to broaden the genetic base of modern cultivars. The landrace
known as “Cipolla rossa di Acquaviva” (Acquaviva red onion, further
referred to as ARO) is traditionally cultivated in a small area of the
Apulia region (southern Italy) and is highly requested by the local market.
Despite representing an important source of income for farmers, the ARO
landrace lacks a solid genetic characterization necessary for its proper
valorisation and protection from frauds. In this work, genotyping-bysequencing (GBS) was used to characterize the genetic variation of seven
onion populations commercialized as ARO, as well as one population of the
landrace “Montoro”, which is phenotypically similar but is typical from a
different cultivation area. A panel of 6,872 SNP markers was used to
perform parametric and non-parametric structure analyses. Four ARO
populations formed a homogeneous genetic group, clearly distinct from the
other ARO and Montoro populations. A set of private alleles was identified
and used to fingerprint the core set by means of SNP-based molecular
barcode, suitable for traceability of marketable product. Overall, the
results of provides insights on the genetic structure of onions marketed as
ARO, and provide a framework for further breeding activities and product
traceability
Delvento C, Arcieri F, Marcotrigiano AR, Guerriero M, Fanelli V, Dellino M, Bouwmeester H, Lotti C, Ricciardi L, Pavan S (2023) High-density linkage mapping and genetic dissection of resistance to broomrape (Orobanche crenata Forsk.) in pea (Pisum sativum L.)
No full textPea (Pisum sativum L.) is a widely cultivated legume of major importance
for global food security and agricultural sustainability. Crenate broomrape
(Orobanche crenata Forsk.) (Oc) is a parasitic weed severely affecting
legumes, including pea, in the Mediterranean Basin and the Middle East.
Previously, the identification of the pea line ‘ROR12’, displaying
resistance to Oc, was reported. Two-year field trials on a segregant
population of 148 F7 recombinant inbred lines (RILs), originating from a
cross between ‘ROR12’ and the susceptible cultivar ‘Sprinter’, revealed
high heritability (0.84) of the ‘ROR12’ resistance source. Genotyping-bysequencing
(GBS) on the same RIL population allowed the construction of a
high-density pea linkage map, which was compared with the pea reference
genome and used for quantitative trait loci (QTL) mapping. Three QTLs
associated with the response to Oc infection, named PsOcr-1, PsOcr-2 and
PsOcr-3, were identified, with PsOcr-1 explaining 69.3% of the genotypic
variance. Evaluation of the effects of different genotypic combinations
indicated additivity between PsOcr-1 and PsOcr-2, and between PsOcr-1 and
PsOcr-3, and epistasis between PsOcr-2 and PsOcr-3. Finally, three
Kompetitive Allele Specific PCR (KASP) marker assays were designed on the
single nucleotide polymorphisms (SNPs) associated with the QTL significance
peaks. Besides contributing to the development of pea genomic resources,
this work lays the foundation for the obtainment of pea cultivars resistant
to Oc and the identification of genes involved in resistance to parasitic
Orobanchaceae
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
Genotyping-by-Sequencing Defines Genetic Structure within the “Acquaviva” Red Onion Landrace
No full textGenetic structure and distinctive features of landraces, such as adaptability to local agro-ecosystems and specific qualitative profiles, can be substantially altered by the massive introduction of allochthonous germplasm. The landrace known as "Cipolla rossa di Acquaviva" (Acquaviva red onion, further referred to as ARO) is traditionally cultivated and propagated in a small area of the Apulia region (southern Italy). However, the recent rise of its market value and cultivation area is possibly causing genetic contamination with foreign propagating material. In this work, genotyping-by-sequencing (GBS) was used to characterize genetic variation of seven onion populations commercialized as ARO, as well as one population of the landrace "Montoro" (M), which is phenotypically similar, but originates from another cultivation area and displays different qualitative features. A panel of 5011 SNP markers was used to perform parametric and non-parametric genetic structure analyses, which supported the hypothesis of genetic contamination of germplasm commercialized as ARO with a gene pool including the M landrace. Four ARO populations formed a core genetic group, homogeneous and clearly distinct from the other ARO and M populations. Conversely, the remaining three ARO populations did not display significant differences with the M population. A set of private alleles for the ARO core genetic group was identified, indicating the possibility to trace the ARO landrace by means of a SNP-based molecular barcode. Overall, the results of this study provide a framework for further breeding activities and the traceability of the ARO landrace
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
GENOTYPING-BY-SEQUENCING OF TWO EX SITU COLLECTIONS PROVIDES INSIGHTS ON THE PEA EVOLUTIONARY HISTORY
No full textPea (Pisum sativum L. subsp. sativum) is one of the oldest domesticated
species and a widely cultivated legume. In this study, we combined data
from two genotyping-by-sequencing (GBS) libraries, each referring to a
different Pisum germplasm collection. The selection of loci covered by both
libraries caused some loss of sequencing information; however, this did not
prevent the obtainment of one of the largest datasets ever used to explore
pea biodiversity, consisting of 652 accessions and 22,127 SNPs. The
analysis of genetic structure allowed to define a spatio-temporal model for
the expansion of pea cultivation from the domestication centre to other
regions of the world. Average decay of linkage disequilibrium (LD) in
distinct pea genetic clusters ranged from a few bases to hundreds of
kilobases, thus indicating different histories in terms of genetic drift
and selection. Genome-wide scan resulted in the identification of putative
selective sweeps associated with pea domestication and breeding, including
genes known to regulate shoot branching, cotyledon colour and resistance to
lodging. In addition to providing information of major interest for
fundamental and applied research on pea, our work describes the first
successful example of integration of different GBS datasets generated from
ex situ collections – a process of potential interest for a variety of
purposes, including conservation genetics, genome-wide association studies,
and breeding
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
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