5,145 research outputs found
Da Giotto a Gentile. Pittura e scultura a Fabriano fra Due e Trecento: una recensione
No full textL’interessante mostra, curata da Vittorio Sgarbi ed allestita presso la Pinacoteca Civica Bruno Molajoli di Fabriano, offre una interessante panoramica della situazione artistica dell’area umbro-marchigiana tra i secoli XIII e XIV.
Contestualmente al percorso espositivo, si inserisce un itinerario nei più importanti siti pittorici della cittadina.
Significative sono le “finestre” aperte su alcune personalità artistiche, come il Maestro di Campodonico ed Allegretto Nuzi, oltre al più noto pittore a cui questo abitato ha dato i natali, Gentile da Fabriano, e sulla tipologia iconografica della Madonna dell’Umiltà, nata in questo contesto geografico e all’interno della cultura francescana
A New <i>Phytophthora</i> sp. causing root and collar rot on <i>Pistacia lentiscus</i> in Italy
No full textLentisk (Pistacia lentiscus L., Anacardiaceae) is an evergreen shrub that is widespread over the Mediterranean Region. The species is also cultivated as an ornamental plant in Italy. In August 2008, a survey carried out in a forest nursery in Sardinia (39°57′N, 9°13′E) revealed the presence of symptoms such as wilting and desiccation of foliage associated with root and collar rot on 1- to 3-year-old potted seedlings of lentisk. Approximately 30% of 1,500 potted plants were affected. A Phytophthora sp. was consistently isolated from infected roots on synthetic mucor agar medium. Colonies on carrot agar (CA) were stellate to slightly radiate with low aerial mycelium
<i>Phytophthora</i>:an ancient, historic, biologically and structurally cohesive and evolutionarily successful generic concept in need of preservation
No full textThe considerable economic and social impact of the oomycete genus Phytophthora is well known. In response to evidence that all downy mildews (DMs) reside phylogenetically within Phytophthora, rendering Phytophthora paraphyletic, a proposal has been made to split the genus into multiple new genera. We have reviewed the status of the genus and its relationship to the DMs. Despite a substantial increase in the number of described species and improvements in molecular phylogeny the Phytophthora clade structure has remained stable since first demonstrated in 2000. Currently some 200 species are distributed across twelve major clades in a relatively tight monophyletic cluster. In our assessment of 196 species for twenty morphological and behavioural criteria the clades show good biological cohesion. Saprotrophy, necrotrophy and hemi-biotrophy of woody and non-woody roots, stems and foliage occurs across the clades. Phylogenetically less related clades often show strong phenotypic and behavioural similarities and no one clade or group of clades shows the synapomorphies that might justify a unique generic status. We propose the clades arose from the migration and worldwide radiation ~ 140 Mya (million years ago) of an ancestral Gondwanan Phytophthora population, resulting in geographic isolation and clade divergence through drift on the diverging continents combined with adaptation to local hosts, climatic zones and habitats. The extraordinary flexibility of the genus may account for its global 'success'. The 20 genera of the obligately biotrophic, angiosperm-foliage specialised DMs evolved from Phytophthora at least twice via convergent evolution, making the DMs as a group polyphyletic and Phytophthora paraphyletic in cladistic terms. The long phylogenetic branches of the DMs indicate this occurred rather rapidly, via paraphyletic evolutionary 'jumps'. Such paraphyly is common in successful organisms. The proposal to divide Phytophthora appears more a device to address the issue of the convergent evolution of the DMs than the structure of Phytophthora per se. We consider it non-Darwinian, putting the emphasis on the emergent groups (the DMs) rather than the progenitor (Phytophthora) and ignoring the evolutionary processes that gave rise to the divergence. Further, the generic concept currently applied to the DMs is narrower than that between some closely related Phytophthora species. Considering the biological and structural cohesion of Phytophthora, its historic and social impacts and its importance in scientific communication and biosecurity protocol, we recommend that the current broad generic concept is retained by the scientific community.</p
Soil- and waterborne Phytophthora species linked to recent outbreaks in Northern California restoration sites
No full textMany studies around the globe have identified plant production facilities as major sources of plant pathogens that may be released in the wild, with significant consequences for the health and integrity of natural ecosystems. Recently, a large number of soilborne and waterborne species belonging to the plant pathogenic genus Phytophthora have been identified for the first time in California native plant production facilities, including those focused on the production of plant stock used in ecological restoration efforts. Additionally, the same Phytophthora species present in production facilities have often been identified in failing restoration projects, further endangering plant species already threatened or endangered. To our knowledge, the identification of Phytophthora species in restoration areas and in plant production facilities that produce plant stock for restoration projects is a novel discovery that finds many land managers unprepared, due to a lack of previous experience with these pathogens. This review summarizes some of the key knowledge about the genus Phytophthora in general and lists some of the many soilborne and waterborne species recently recovered from some California restoration sites and plant production facilities
Introducing “La fabrique du droit”. A Conversation with Bruno Latour
No full textBruno Latour talks with Paolo Landri about his book on the Conseil d'Etat (La Fabrique du droit). The conversation was held in 2006 at the time of the Italian translation of the book and illustrates the research project and the difficulties the author had in the field. At the same time, it clarifies the trajectories of Bruno Latour's work and theoretical framework of his program of study with respect to sociology, anthropology, and philosophy of law. The conversation helps to understand the open-ended character of Bruno Latour's research and reflection including STS as well as sociological, anthropological and philosophical themes
Diplodia africana causing dieback disease on Juniperus phoenicea: a new host and first report in the northern hemisphere
No full textDiversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.
No full textThe Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago
Potassium Phosphonate Induces Resistance in Sweet Chestnut against Ink Disease Caused by Phytophthora Species
No full textInk disease, caused by Phytophthora spp., represents a serious threat to sweet chestnuts throughout their distribution area. Among the control strategies, new perspectives have been offered by using potassium phosphonate, which indirectly controls Phytophthora diseases by acting on both host physiology and host-pathogen interactions. In this study, we tested in planta the effectiveness of trunk injection with K-phosphonate against seven different Phytophthora species associated with ink disease. For the two most aggressive species, P. cinnamomi and P. ×cambivora, the treatments were repeated at two different environmental conditions (a mean temperature of 14.5 °C vs. 25 °C) and tree phenology stages. The results obtained in this study demonstrated that K-phosphonate could contain the development of Phytophthora infection in phloem tissues. However, its effectiveness varied based on the concentration applied and the Phytophthora species tested. A concentration of 280 g/L of K-phosphonate was the most effective, and in some cases, callus formation around the necrotic lesion was detected. Overall, this study broadens the knowledge of endotherapic treatments with K-phosphonate as an effective measure for managing chestnut ink disease. Interestingly, the increase in mean temperature had a positive impact on the development of P. cinnamomi lesions on chestnut phloem tissues
PAL enzymatic activity (phenylalanine ammonium lyase) in pigmented and white myrtle (Myrtus communis L.) cultivars
No full textThe myrtle (Myrtus communis L.) is a spontaneous aromatic shrub, belonging
to the Myrtaceae family. Since ancient times, the plant has been used for medical
purposes. Due to the high quantity of essential oils in the vegetative organs,
the myrtle is used in pharmaceutical, cosmetic, and food fields.
Numerous studies show the high antioxidant activity of myrtle berries and leaves
and its derived products. Phenolic compounds, as flavonoids and tannins,
are the main responsible of this property.
Most phenols compounds originate from the phenylalanine produced by the
biosynthetic pathway of shikimic acid. The enzyme phenylalanine ammonia
lyase (PAL) catalyzes condensation of a molecule of L-phenylalanine and four
molecules of coenzyme-A with the formation of a trans-cinnamic acid and
ammonium ion. The conversion of trans-cinnamic acid into flavonoids, such as
anthocyanins, requires other reactions catalyzed by specific enzymes.
In several fruit species, the accumulation of anthocyanins and other flavonoids
correlated with PAL activity, through the support of cinnamic acid.
The aim of this work was to study the activity of PAL in berry and leaves as
related to the changes in the amounts of total polyphenols, anthocyanins, flavonoids,
and tannins from flowering to berry maturation in two model cultivars
of myrtle selected in Sardinia: One with pigmented berries and one with unpigmented
berries.
PAL activity was quite constant in leaves and variable in berries, greater in berries
of pigmented cultivar “Giovanna” and increasing from berry color-break
to full ripening. In berries, a positive correlation between PAL and flavonoids
(r = 0.44), and between PAL and anthocyanins (r = 0.69), as well as a negative
correlation between PAL and total polyphenols (r = −0.471), were found. Our
results show that activity of the PAL enzyme in myrtle berries is associated
with accumulation of flavonoids and anthocyanins, suggesting that PAL is a
limiting-enzyme in flavonoids biosynthesis
Author Correction: Collection of the digital data from the neurological examination.
No full textIn this article, the corresponding author was inadvertently designated only to “Bruno Kusznir Vitturi” but it should have been “Bruno Kusznir Vitturi” and “Walter Maetzler”. The original article has been corrected
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