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A successful defence strategy in grapevine cultivar 'Tocai friulano' provides compartmentation of grapevine Flavescence dorée phytoplasma
Get PDFBackgroundFlavescence doree (FD) is a grapevine disease caused by phytoplasma and it is one of the most destructive pathologies in Europe. Nowadays, the only strategies used to control the epidemics are insecticides against vector, but more sustainable techniques are required. Completely resistant Vitis vinifera varieties have not been uncovered yet, but differences in susceptibility among cultivars and spontaneous recovery from FD symptoms have been observed. The grapevine cultivar 'Tocai friulano' shows very low susceptibility to FD but its defence strategy to counteract the phytoplasma spread has not been deciphered yet. In this work, the mechanisms occurring within 'Tocai friulano' FD-infected plants were examined in depth to identify the phytoplasma distribution and the defence pathways involved.ResultsIn 'Tocai friulano' symptoms of FD-infection remained confined near the area where they appeared during all the vegetative season. Analyses of secondary phloem showed a total absence of FD phytoplasma (FDp) in the trunk and its disappearance in 2-year-old arms from July to November, which was different from 'Pinot gris', a highly susceptible variety.Diverse modulations of defence genes and accumulation of metabolites were revealed in 1-year-old canes of 'Tocai friulano' FD-infected plants, depending on the sanitary status. Symptomatic portions showed high activation of both jasmonate- and salicylate-mediated responses, together with a great accumulation of resveratrol. Whereas activation of jasmonate-mediated response and high content of epsilon-viniferin were identified in asymptomatic 1-year-old cane portions close to the symptomatic ones.ConclusionSuccessful defence mechanisms activated near the symptomatic areas allowed the compartmentation of FD symptoms and phytoplasmas within the infected 'Tocai friulano' plants. These results could suggest specific agronomical practices to be adopted during FD management of this variety, and drive research of resistance genes against FD
Fig. 4. Gyponana mali DeLong, 1942 in First records of the North American leafhopper Gyponana mali (Hemiptera: Cicadellidae) invading urban gardens and agroecosystems in Europe
No full textFig. 4. Gyponana mali DeLong, 1942:A – aedeagus, caudal view (reprinted from Hൺආංඅඍඈඇ 1982); B – aedeagus, ventral view (left) and style, lateral view (right; reprinted from DൾLඈඇǤ & F*©ൾඒඍൺǤ 1964).Gyponana extenda DeLong, 1942: C – aedeagus, caudal view and style, lateral view, with structural variation from "s" to "v" form (reprinted from Hൺආංඅඍඈඇ 1982); D – aedeagus, ventral view (left) and style, lateral view (right; reprinted from DൾLඈඇǤ & F*©ൾඒඍൺǤ 1964).Published as part of Trivellone, Valeria, Forte, Vally, Filippin, Luisa & Dietrich, Christopher H., 2021, First records of the North American leafhopper Gyponana mali (Hemiptera: Cicadellidae) invading urban gardens and agroecosystems in Europe, pp. 213-219 in Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1) on page 216, DOI: 10.37520/aemnp.2021.011, http://zenodo.org/record/503739
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
A GRAPEVINE GENETIC LINKAGE MAP TO FIND OUT QUANTITATIVE TRAIT LOCI RESPONSIBLE FOR LOWER SUSCEPTIBILITY TO FLAVESCENCE DORÉE
No full textFlavescence dorée (FD) is one of the most destructive grapevine yellows (GY) diseases, and a
quarantine pest in Europe. It is caused by phytoplasmas, which are transmitted among plants by the
leafhopper Scaphoideus titanus Ball. Although grapevine varieties completely resistant to FD have
not been uncovered yet, some inter- and intra-specific differences in susceptibility have already
been observed as poor presence of infected vines in vineyard, no severe symptoms and recovery
ability of plants. The different behavior among grapevine varieties suggests the presence of putative
several loci, not yet disclosed, associated with high or low susceptibility to FD. In this context, the
development of a genetic map is the first crucial step to dissect the genetic basis that regulate FD
incidence. The aim of our study is to build a high-density genetic linkage map using F1 progeny
from a cross ‘Chardonnay x Tocai friulano’, characterized by high and low susceptibility to FD,
respectively. Two hundred and thirty F1 individuals were first checked with ten SSR (Simple
Sequence Repeats) markers to exclude self-fertilized individuals. A total of 184 individuals and
their parents were then subjected to Genotyping by Sequencing (GBS). A panel of 122,049 Single
Nucleotide Polymorphisms (SNPs) generated by GBS was filtered and used to construct a genetic
linkage map using the JoinMap 4 software. The genetic map resulted in 2,923 markers, distributed
among 19 linkage groups and covering 1336.05 cM, with an average distance of 2 cM between two
markers. At the same time, the F1 population is undergoing phenotyping. The information derived
from the genetic map will be combined with phenotypic data points to identify QTLs involved in
high or low FD susceptibility
Enhancing the volatile organic compound and biomass production by three biocontrol potential bacteria in corn steep liquor growth medium and development of cell freeze-drying process
No full textsp. 3R4, and Bacillus sp. T22, to assess their potential application as biocontrol agents by using the ecofriendly and low-cost substrate Corn
Steep Liquor (CSL) medium. Analyses of antagonism through volatile organic compounds (VOCs) production, biofilm formation, and growth
perf ormance w ere carried out.
Methods and results: Dual antagonism assay showed that all strains displayed significant ant agonistic activit y against Botrytis cinerea through
VOCs. Gas chromatography demonstrated that strains in the CSL exhibited higher VOCs production than nutrient medium. Moreo v er, enhanced
biofilm formation analysed by Calgary Biofilm Device, growth, and biomass were noted in CSL cultures. Pseudomonas protegens MP1 2, whic h
sho w ed higher cell concentration and biomass yield, was selected for freeze-drying treatments. Storage cell viability assays evidenced that it
can be effectively preserved for nearly 7 months at 4 ◦C.
Conclusion: The results here obtained showed that CLS medium enhanced VOCs production, biofilm formation, growth, and biomass of the
antagonistic bacteria of the three strains. Eventually, the more effective strain P. protegens MP12 can be stored for nearly 7 months at 4 ◦C
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