Characterization and pathogenicity of Pestalotiopsis uvicola causing black leaf spot on carob (Ceratonia siliqua L.) in Italy

During spring 2013, several carob plants (Ceratonia siliqua L.), showing symptoms of necrotic black lesions on leaves, were observed in Capri Island, Southern Italy. Acervuli, producing conidia with septa and appendages, appeared in the centre of the lesions. In this report, the identification of the causal agent of this disease was made applying Koch’s postulates. Morphological characteristics of colony (colour and mycelium appearance) and conidia (size, shape, number of septa, length and number of apical and basal appendages) were characterized to identify the pathogen. Moreover, for a rapid and unambiguous identification of the fungal species, the internal transcribed spacers, comprising the 5.8 rDNA gene (ITS1-5.8-ITS2), were amplified by PCR, using the genomic DNA extracted from the isolated colonies, and sequenced. The fungus isolated was ascribed to the species Pestalotiopsis uvicola (Speg.) Bissett. Phylogenetic analysis, performed with sequences present in GenBank database, showed that carob isolates clustered with P. uvicola isolates from North America and Italy, separately from Australian, Indian and Chinese isolates. P. uvicola isolates were pathogenic when artificially inoculated on carob leaves. To the best of our knowledge, this is the first report of P. uvicola on carob.     

Partition behavior of virgin olive oil phenolic compounds in oil-brine mixtures during thermal processing for fish canning

The chemical modifications and partitioning toward the brine phase (5% salt) of major phenol compounds of extra virgin olive oil (EVOO) were studied in a model system formed by sealed cans filled with oil-brine mixtures (5:1, v/v) simulating canned-in-oil food systems. Filled cans were processed in an industrial plant using two sterilization conditions commonly used during fish canning. The partitioning of phenolic compounds toward brine induced by thermal processing was studied by reversed-phase high-performance liquid chromatographic analysis of the phenol fraction extracted from oils and brine. Hydroxytyrosol (1), tyrosol (2), and the complex phenolic compounds containing 1 and 2 (i.e., the dialdehydic form of decarboxymethyl oleuropein aglycon 3, the dialdehydic form of decarboxymethyl ligstroside aglycon 4, and the oleuropein aglycon 6) decreased in the oily phase after sterilization with a marked partitioning toward the brine phase. The increase of the total amount of 1 and 2 after processing, as well as the presence of elenolic acid 7 released in brine, revealed the hydrolysis of the ester bond of hydrolyzable phenolic compounds 3, 4, and 6 during thermal processing. Both phenomena (partitioning toward the water phase and hydrolysis) contribute to explain the loss of phenolic compounds exhibited by EVOO used as filling medium in canned foods, as well as the protection of n-3 polyunsaturated fatty acids in canned-in-EVOO fish products.     

Delta-viniferin,a resveratrol dehydrodimer: one of the major stilbenes synthesized by stressed grapevine leaves

Delta-viniferin is a resveratrol dehydrodimer, an isomer of epsilon-viniferin. This compound has been reported as a molecule produced in vitro by the oxidative dimerization of resveratrol by plant peroxidases or fungal laccases. It was also recently identified in wines and in grape cell cultures. We have now identified this dimer by NMR, high-performance liquid chromatography-diode array detection (HPLC-DAD), and HPLC-mass spectrometry (MS) in grapevine leaves infected by Plasmopara viticola (downy mildew) or UV-C irradiated. Its concentration was higher than that of epsilon-viniferin and constitutes one of the most important phytoalexins derived from resveratrol.     

Antispasmodic saponins from bulbs of red onion, Allium cepa L. var. Tropea

A phytochemical analysis of the polar extract from the red bulbs of Allium cepa L. var. Tropea, typical of Calabria, a southern region of Italy, was performed extensively for the first time, leading to the isolation of four new furostanol saponins, named tropeoside A1/A2 (1a/1b) and tropeoside B1/B2 (3a/3b), along with the respective 22-O-methyl derivatives (2a/2b and 4a/4b), almost certainly extraction artifacts. High concentrations of ascalonicoside A1/A2 (5a/5b) and ascalonicoside B (6), previously isolated from Allium ascalonicum Hort., were also found. This is the first report of furostanol saponins in this A. cepa variety. The chemical structures of the new compounds were established through a combination of extensive nuclear magnetic resonance, mass spectrometry and chemical analyses. High concentrations of quercetin, quercetin 4(I)-glucoside, taxifolin, taxifolin 7-glucoside, and phenylalanine were also isolated. The new saponins were found to possess antispasmodic activity in the guinea pig isolated ileum; such an effect might contribute to explaining the traditional use of onion in the treatment of disturbances of the gastrointestinal tract.     

Correction to: Assessment of cable tensile forces in active winch-assist harvesting using an anchor machine configuration

European Journal of Forest Research - A correction to this paper has been published: https://doi.org/10.1007/s10342-021-01385-w     

Structural diversity and height growth models in urban forest plantations: A case-study in northern Italy

Current knowledge on the growth models of urban forest plantations several years after their establishment still remains poor and fragmentary. Furthermore few studies have assessed the growth of urban plantations on reclaimed land, such as brownfield sites.This paper assesses urban forest plantations in terms of tree height growth, crown width and vertical structural using as a case study tree inventory-data collected in an urban forest plantation (Parco Nord Milano, PNM northern Italy). In this research tree inventory-data was used to achieve the following objectives: (i) to develop a series of tree height-growth models and tree crown-width models for the main taxonomic units in the study-area; (ii) to analyse the temporal pattern of current increments of tree height; (iii) to assess the vertical stratification of tree crowns using a method developed by Latham et al. (1998).The results suggest that during the earlier stage after planting, trees reach high levels of growth (tree height and crown width) regardless of the taxonomic unit. Evidence is found to support a high level of spatial competition between individual trees of different taxonomic units in as little as 15–18 years. Competition between trees appears to be mainly affected by diametrical differentiation rather than hypsometric variation: trees grow more in diameter than in height. Furthermore a decrease in longitudinal growth was observed for most tree species while the radial growth tends to be constant over time. The research at PNM shows that in temperate climates this can be achieved in less than 30 years. We believe that these analyses could provide important data supporting the planning of new urban forest plantations on reclaimed land and inter alia provide some answers to the questions around plantations growth evaluation and management.     

Cerebral Hirano-like bodies in an alpaca (Vicugna pacos): histologic and ultrastructural characterization

A 14-year-old female alpaca (Vicugna pacos) was presented with a 1-week history of lethargy and anorexia and a 2-day history of recumbency, trembling, and hypothermia. There were no significant gross findings on postmortem examination. Hematoxylin and eosin-stained sections of brain demonstrated the presence of intracytoplasmic crystalline eosinophilic rod-shaped inclusions, mainly in the hippocampal pyramidal cells. Immunohistochemical staining for synuclein, tau protein, ubiquitin, and smooth muscle actin was negative. All inclusions were positive with phosphotungstic acid hematoxylin. Ultrastructurally, the inclusions were multilamellar and filamentous with longitudinal herringbone pattern and cross-sectional latticelike structure. The combination of hematoxylin and eosin appearance, special stains, immunostaining, and ultrastructural findings was consistent with Hirano-like bodies. The Hirano-like bodies were highly unlikely to be the cause of the neurologic signs experienced by this alpaca. To the authors' knowledge, this is the first report of spontaneous cerebral Hirano-like bodies in an alpaca.     

Evaluation of a new natural adjuvant obtained from locust bean gum to reduce the amount of copper necessary to control downy mildew of grapevine

Journal of Plant Diseases and Protection - Two field trials in integrated cultivation (2014 and 2016) were carried out with the aim to evaluate the efficacy and the persistence of copper...