1,720,964 research outputs found
First report of powdery mildew caused by Erysiphe platani in Ailanthus altissima, the tree-of-heaven, in the Mediterranean basin, Italy
No full textIn August 2018, a tree-of-heaven (Ailanthus altissima) showing symptoms of powdery mildew was found in Pisa, Italy. Morphological characteristics of the anamorph and molecular sequence analysis of the internal transcribed spacer region of rDNA verified the fungus as Erysiphe platani. In a pathogenicity test, powdery mildew patches were present on leaf surfaces 2 weeks after inoculation with the isolate. This is the first report of E. platani causing powdery mildew on ailanthus in the Mediterranean basin. The fungus, whose historical host range was confined to the genus Platanus, has expanded its host range to Ailanthus in Italy
Genome Resources of Verticillium dahliae VdGL16: the causal agent of vascular wilt on the invasive species Ailanthus altissima
No full textVerticillium species are known as plant pathogens responsible for wilt diseases in a large variety of dicotyledon plants and crops in many parts of the world. Here we present the draft genome sequence of Verticillium dahliae Kleb. (strain VdGL16) isolated in Italy from the invasive alien species Ailanthus altissima (Mill.; commonly known as tree-of-heaven) showing Verticillium wilt symptoms. The comparison between the newly sequenced genome with those publicly available revealed candidate genes putatively involved in pathogenicity. The genome represents a new useful source for future research on Verticillium genetics and biology as well as research on novel approaches in the control of A. altissima
Transient waterlogging events impair shoot and root physiology and reduce grain yield of durum wheat cultivars
Full text linkDurum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn) is a staple crop of the Mediterranean countries, where more frequent waterlogging events are predicted due to climate change. However, few investigations have been conducted on the physiological and agronomic responses of this crop to waterlogging. The present study provides a comprehensive evaluation of the effects of two waterlogging durations (i.e., 14 and 35 days) on two durum wheat cultivars (i.e., Svevo and Emilio Lepido). An integrated analysis of an array of physiological, biochemical, biometric, and yield parameters was performed at the end of the waterlogging events, during recovery, and at physiological maturity. Results established that effects on durum wheat varied depending on waterlogging duration. This stress imposed at tillering impaired photosynthetic activity of leaves and determined oxidative injury of the roots. The physiological damages could not be fully recovered, subsequently slowing down tiller formation and crop growth, and depressing the final grain yield. Furthermore, differences in waterlogging tolerance between cultivars were discovered. Our results demonstrate that in durum wheat, the energy maintenance, the cytosolic ion homeostasis, and the ROS control and detoxification can be useful physiological and biochemical parameters to consider for the waterlogging tolerance of genotypes, with regard to sustaining biomass production and grain yield
Sustainable Strategies to Counteract Mycotoxins Contamination and Cowpea Weevil in Chickpea Seeds during Post-Harvest
No full textMycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of deleterious organisms in foodstuff. Ozone treatment (O-3, 500 ppb for 30, 60 or 90 min) and high nitrogen concentration (N-2, 99% for 21 consecutive days) were tested in the post-harvest management of four batches of Cicer arietinum grains to control the presence of mycotoxigenic fungi and their secondary metabolites, as well as pest (i.e., Callosobruchus maculatus) infestation. At the end of the treatment, O-3 significantly decreased the incidence of Penicillium spp. (by an average of -50%, independently to the time of exposure) and reduced the patulin and aflatoxins content after 30 min (-85 and -100%, respectively). High N-2 concentrations remarkably reduced mycotoxins contamination (by an average of -94%) and induced pest mortality (at 100% after 5 days of exposure). These results confirm the promising potential of O-3 and N-2 in post-harvest conservation strategies, leading to further investigations to evaluate the effects on the qualitative characteristics of grains
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
Identification of key responsive leaf physiochemical traits for ozone sensitivity in 16 Italian cultivars of Triticum durum subjected to peak concentrations
No full textPlants of 16 Italian cultivars of durum wheat at the tillering stage were exposed to a single pulse of ozone (O-3 , 200 ppb, 5 h) to reveal the mechanisms explaining their O-3 tolerance/sensitivity by considering some leaf physiochemical traits [e.g., stomatal conductance, photosystem II (PSII) efficiency, antioxidant enzyme activity, and phytohormone synthesis]. At the end of the recovery period (48 h from the beginning of the exposure), all cultivars showed visible foliar injury in the form of widespread chlorosis which developed in bifacial ivory necrotic lesions scattered among the leaf veins of completely expanded leaves. Mongibello leaves showed not only the highest severity of visible injury (McKinney index = 62%), but also a reduction of PSII performance (Fv/Fm ratio: -22% compared with controls) together with an activation of the dissipation of the excess excitation energy as heat (qNP: +35%). The photosynthetic impairment observed throughout the whole experiment, was likely due to stomatal limitations (gs: -36% as average) and indicated that this cultivar was very sensitive to a pulse of O-3 . Similar results were obtained for Latino and Meridiano. Conversely, Iride, Orobel, and Portorico showed the lowest severity of visible injury (McKinney index around 13%) suggesting that they could be considered tolerant to a pulse of O-3 . These cultivars showed none or only transient changes due to O-3 in terms of photosynthetic activity (e.g., A values), while the slight decrease of Fv/Fm ratio did not determine the photoinhibition of the PSII activity, since mechanisms for dissipating excess excitation energy were being activated. Ozone treatment induced a significant reduction of CO2 assimilation rate (-34%) in Orobel and this is not attributable to stomatal and non-stomatal limitations. The remaining cultivars were considered moderately sensitive to O-3 , with McKinney index in the range of 20-43%. The measured biochemical traits are not decisive in determining the O-3 sensitivity. In particular, the activity of phenylalanine ammonia lyase increased only in seven cultivars; among them, only in Latino, Vetrodur, and Simeto, this enhancement reflected in an accumulation of phenolic compounds suggesting potential higher protection against reactive oxygen species. This work highlights the relevance of identifying O-3 -sensitive cultivars, in the optic to develop sustainable strategies to mitigate the impact of peak O-3 episodes on wheat production
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
Nutrient fertilization mitigates the effects of ozone exposure on poplar plants.
Full text linkThe progressive salinization of soils irrigated with salty water and
salt-water intrusion of groundwater bodies can limit crop production
in many areas, especially in the Mediterranean basin. The current
background tropospheric ozone (O3) levels are high enough to negatively
affect plant physiological and productive performances. In
this work, one-year-old saplings of pomegranate (Punica granatum
L., cv. ‘Dente di cavallo’) were exposed to two levels of O3 [AOT40
values were 21.51 in ambient air (AA), and 58.74 ppm h, in 2AA]
and two levels of salinity, denoted as No Salt (NS) and Salt (S, the
electrical conductivity and pH of the irrigation water were 5.5 mS
cm-1 and 7.6 with 50 mM of NaCl) for four consecutive months in an
O3 FACE open air facility. Under O3 (alone or in combination with
salt), plants developed visible stipples of browning tissue localized in
the interveinal adaxial leaf surface. At ecophysiological level, salt
stress further affected the photosynthetic performance (-17% compared
to AA_NS). By contrast, salinity did not induce oxidative
damage [as confirmed by unchanged malondialdehyde (MDA)
levels]. Under 2AA conditions, O3 alone reduced the stress tolerance,
as confirmed by the production of reactive oxygen species (+10 and
+225% of anion superoxide and hydrogen peroxide, respectively),
the increase of superoxide dismutase activity (+9%) and the concomitant
membrane denaturation (+198% of MDA content). According to
Bansal calculation, the combination of both stressors had a synergistic
effect in terms of oxidative damage and increased activity of
catalase
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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