scholarly journals An Evaluation of Monitoring Surveys of the Quarantine Bacterium Xylella Fastidiosa Performed in Containment and Buffer Areas of Apulia, Southern Italy

2019 ◽  
Vol 24 (2) ◽  
pp. 96-99 ◽  
Author(s):  
Marco Scortichini ◽  
Gianluigi Cesari
Keyword(s):  
Pathogen Detection ◽  
Southern Italy ◽  
Plant Protection ◽  
Xylella Fastidiosa ◽  
Epidemiological Data ◽  
Molecular Techniques ◽  
Tree Age ◽  
The European Union ◽  
Detection Techniques ◽  
Olive Trees

Introduction: Xylella fastidiosa is a quarantine phytopathogen for the European Plant Protection Organization and currently infects olive trees in the Apulia region (southern Italy). Upon the Implementing Decision of the European Union 2016/764 of May 12, 2016, extensive monitoring surveys were performed on approximately 190 000 ha to ascertain the possible occurrence of X. fastidiosa. Objectives: The primary objectives of the analysis were to start to collect epidemiological data on X. fastidiosa occurrence in areas far from the initial outbreaks and discuss the results of the pathogen detection. Methods: A total of 220 279 olive trees were inspected. Basic information on farm and trees management was obtained. A total of 13 706 olive trees were analyzed through serological and molecular techniques to verify the possible occurrence of the bacterium. Results: The cultivars “Nociara,” “Cima di Melfi,” and “Cellina di Nardò” showed the highest occurrence of decline symptoms. Tree age appears to be related to the incidence of decline symptoms. Olive trees growing in well-managed soils showed fewer symptoms than trees cultivated in farms where such agronomic techniques are not regularly performed. X. fastidiosa was detected in 2078 samples taken from symptomatic trees and 1653 samples obtained from asymptomatic trees. In 3300 samples taken from symptomatic trees, the bacterium was not detected. Conclusions: Implementation and utilization of reliable in situ detection techniques could increase the number of sampled trees in each plot, thus allowing a more extensive and robust assessment of X. fastidiosa–infected plants in areas where the pathogen inoculums are still low.

scholarly journals Diversity Evaluation of Xylella fastidiosa from Infected Olive Trees in Apulia (Southern Italy)

2016 ◽  
Vol 32 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Stefania M. Mang ◽  
Salvatore Frisullo ◽  
Hazem S. Elshafie ◽  
Ippolito Camele
Keyword(s):  
Southern Italy ◽  
Xylella Fastidiosa ◽  
Olive Trees ◽  
Diversity Evaluation

scholarly journals Development of an Efficient Real-Time Quantitative PCR Protocol for Detection ofXanthomonas arboricolapv. pruni inPrunusSpecies

2010 ◽  
Vol 77 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Ana Palacio-Bielsa ◽  
Jaime Cubero ◽  
Miguel A. Cambra ◽  
Raquel Collados ◽  
Isabel M. Berruete ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Extraction ◽  
Plant Material ◽  
Pathogen Detection ◽  
Plant Protection ◽  
The European Union ◽  
Real Time Quantitative Pcr ◽  
Field Samples ◽  
Mediterranean Plant ◽  
Different Origins

ABSTRACTXanthomonas arboricolapv. pruni, the causal agent of bacterial spot disease of stone fruit, is considered a quarantine organism by the European Union and the European and Mediterranean Plant Protection Organization (EPPO). The bacterium can undergo an epiphytic phase and/or be latent and can be transmitted by plant material, but currently, only visual inspections are used to certify plants as beingX. arboricolapv. pruni free. A novel and highly sensitive real-time TaqMan PCR detection protocol was designed based on a sequence of a gene for a putative protein related to an ABC transporter ATP-binding system inX. arboricolapv. pruni. Pathogen detection can be completed within a few hours with a sensitivity of 102CFU ml−1, thus surpassing the sensitivity of the existing conventional PCR. Specificity was assessed forX. arboricolapv. pruni strains from different origins as well as for closely relatedXanthomonasspecies, non-Xanthomonasspecies, saprophytic bacteria, and healthyPrunussamples. The efficiency of the developed protocol was evaluated with field samples of 14Prunusspecies and rootstocks. For symptomatic leaf samples, the protocol was very efficient even when washed tissues of the leaves were directly amplified without any previous DNA extraction. For samples of 117 asymptomatic leaves and 285 buds, the protocol was more efficient after a simple DNA extraction, andX. arboricolapv. pruni was detected in 9.4% and 9.1% of the 402 samples analyzed, respectively, demonstrating its frequent epiphytic or endophytic phase. This newly developed real-time PCR protocol can be used as a quantitative assay, offers a reliable and sensitive test forX. arboricolapv. pruni, and is suitable as a screening test for symptomatic as well as asymptomatic plant material.

scholarly journals Aphrophoridae Role in Xylella fastidiosa subsp. pauca ST53 Invasion in Southern Italy

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1035
Author(s):  
Ugo Picciotti ◽  
Nada Lahbib ◽  
Valdete Sefa ◽  
Francesco Porcelli ◽  
Francesca Garganese
Keyword(s):  
Pest Management ◽  
Plant Pathogen ◽  
Southern Italy ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Disease Spread ◽  
Insect Vector ◽  
Transmission Control ◽  
Olive Quick Decline Syndrome ◽  
Olive Trees

The Philaenus spumarius L. (Hemiptera Aphrophoridae) is a xylem-sap feeder vector that acquires Xylella fastidiosa subsp. pauca ST53 during feeding on infected plants. The bacterium is the plant pathogen responsible for olive quick decline syndrome that has decimated olive trees in Southern Italy. Damage originates mainly from the insect vector attitude that multiplies the pathogen potentialities propagating Xf in time and space. The principal action to manage insect-borne pathogens and to contain the disease spread consists in vector and transmission control. The analysis of an innovative and sustainable integrated pest management quantitative strategy that targets the vector and the infection by combining chemical and physical control means demonstrates that it is possible to stop the Xylella invasion. This review updates the available topics addressing vectors’ identification, bionomics, infection management, and induced disease by Xylella invasion to discuss major available tools to mitigate the damage consequent to the disease.

scholarly journals Fast Detection of Olive Trees Affected by Xylella Fastidiosa from UAVs Using Multispectral Imaging

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4915 ◽  
Author(s):  
Attilio Di Nisio ◽  
Francesco Adamo ◽  
Giuseppe Acciani ◽  
Filippo Attivissimo
Keyword(s):  
Multispectral Imaging ◽  
Xylella Fastidiosa ◽  
Similarity Coefficient ◽  
Segmentation Algorithm ◽  
Dice Similarity Coefficient ◽  
The European Union ◽  
The South ◽  
Linear Discriminant ◽  
Fast Detection ◽  
Olive Trees

Xylella fastidiosa (Xf) is a well-known bacterial plant pathogen mainly transmitted by vector insects and is associated with serious diseases affecting a wide variety of plants, both wild and cultivated; it is known that over 350 plant species are prone to Xf attack. In olive trees, it causes olive quick decline syndrome (OQDS), which is currently a serious threat to the survival of hundreds of thousands of olive trees in the south of Italy and in other countries in the European Union. Controls and countermeasures are in place to limit the further spreading of the bacterium, but it is a tough war to fight mainly due to the invasiveness of the actions that can be taken against it. The most effective weapons against the spread of Xf infection in olive trees are the detection of its presence as early as possible and attacks to the development of its vector insects. In this paper, image processing of high-resolution visible and multispectral images acquired by a purposely equipped multirotor unmanned aerial vehicle (UAV) is proposed for fast detection of Xf symptoms in olive trees. Acquired images were processed using a new segmentation algorithm to recognize trees which were subsequently classified using linear discriminant analysis. Preliminary experimental results obtained by flying over olive groves in selected sites in the south of Italy are presented, demonstrating a mean Sørensen–Dice similarity coefficient of about 70% for segmentation, and 98% sensitivity and 93% precision for the classification of affected trees. The high similarity coefficient indicated that the segmentation algorithm was successful at isolating the regions of interest containing trees, while the high sensitivity and precision showed that OQDS can be detected with a low relative number of both false positives and false negatives.

scholarly journals Dispersal of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa, in Olive Grove and Meadow Agroecosystems

2020 ◽  
Author(s):  
Nicola Bodino ◽  
Vincenzo Cavalieri ◽  
Crescenza Dongiovanni ◽  
Anna Simonetto ◽  
Matteo Alessandro Saladini ◽  
...  
Keyword(s):  
Southern Italy ◽  
Xylella Fastidiosa ◽  
Olive Grove ◽  
Coefficient Estimate ◽  
Philaenus Spumarius ◽  
South Italy ◽  
Median Distance ◽  
Olive Trees ◽  
Dispersal Kernels ◽  
Key Parameter

Abstract The introduction of the Xylella fastidiosa Wells bacterium into Apulia (South Italy) has caused the massive dieback of olive trees, and is threatening olive production throughout the Mediterranean Region. The key vector of X. fastidiosa in Europe is the spittlebug Philaenus spumarius L. The dispersal capabilities of P. spumarius are poorly known, despite being a key parameter for the prediction of the spread of the bacterium. In this study, we have examined the dispersal of P. spumarius adults in two different agroecosystems in Italy: an olive grove in Apulia (Southern Italy) and a meadow in Piedmont (Northern Italy). Insects were marked with albumin and released during seven independent trials over 2 yr. The recapture data were pooled separately for each agroecosystem and used to estimate the dispersal kernels of P. spumarius in the olive grove and in the meadow. The diffusion coefficient estimate for P. spumarius was higher in the meadow than in the olive grove. The median distance from the release point for 1 d of dispersal was 26 m in the olive grove and 35 m in the meadow. On the basis of our model, we estimated that 50% of the spittlebug population remained within 200 m (98% within 400 m) during the 2 mo period of high abundance of the vector on olives in Apulia. The dispersal of P. spumarius is thus limited to some hundreds of meters throughout the whole year, although it can be influenced to a great extent by the structure of the agroecosystem.

scholarly journals Effect of the Application Date of Fertilizer Containing Silicon and Potassium on the Yield and Technological Quality of Sugar Beet Roots

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 370
Author(s):  
Arkadiusz Artyszak ◽  
Dariusz Gozdowski ◽  
Alicja Siuda
Keyword(s):  
Sugar Beet ◽  
Foliar Application ◽  
Plant Protection ◽  
Plant Protection Products ◽  
Water Shortage ◽  
The European Union ◽  
Yield Increase ◽  
Time Of Application ◽  
Technological Quality

Water shortage and drought are a growing problem in Europe. Therefore, effective methods for limiting its effects are necessary. At the same time, the “field to fork” strategy adopted by the European Commission aims to achieve a significant reduction in the use of plant protection products and fertilizers in the European Union. In an experiment conducted in 2018–2020, the effect of the method of foliar fertilization containing silicon and potassium on the yield and technological quality of sugar beet roots was assessed. The fertilizer was used in seven combinations, differing in the number and time of application. The best results were obtained by treating plants during drought stress. The better soil moisture for the plants, the smaller the pure sugar yield increase was observed. It is difficult to clearly state which combination of silicon and potassium foliar application is optimal, as their effects do not differ greatly.

scholarly journals Semi-Automatic Method for Early Detection of Xylella fastidiosa in Olive Trees Using UAV Multispectral Imagery and Geostatistical-Discriminant Analysis

2020 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Annamaria Castrignanò ◽  
Antonella Belmonte ◽  
Ilaria Antelmi ◽  
Ruggiero Quarto ◽  
Francesco Quarto ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Early Detection ◽  
Plant Pathogens ◽  
Early Stage ◽  
Xylella Fastidiosa ◽  
Mediterranean Countries ◽  
Parametric Classification ◽  
Aerial Vehicle ◽  
Olive Groves ◽  
Olive Trees

Xylella fastidiosa subsp. pauca (Xfp) is one of the most dangerous plant pathogens in the world. Identified in 2013 in olive trees in south–eastern Italy, it is spreading to the Mediterranean countries. The bacterium is transmitted by insects that feed on sap, and causes rapid wilting in olive trees. The paper explores the use of Unmanned Aerial Vehicle (UAV) in combination with a multispectral radiometer for early detection of infection. The study was carried out in three olive groves in the Apulia region (Italy) and involved four drone flights from 2017 to 2019. To classify Xfp severity level in olive trees at an early stage, a combined method of geostatistics and discriminant analysis was implemented. The results of cross-validation for the non-parametric classification method were of overall accuracy = 0.69, mean error rate = 0.31, and for the early detection class of accuracy 0.77 and misclassification probability 0.23. The results are promising and encourage the application of UAV technology for the early detection of Xfp infection.

scholarly journals HPLC-MS/MS method applied to an untargeted metabolomics approach for the diagnosis of “olive quick decline syndrome”

2021 ◽  
Author(s):  
Sabrina Di Masi ◽  
Giuseppe E. De Benedetto ◽  
Cosimino Malitesta ◽  
Maria Saponari ◽  
Cinzia Citti ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
Xylella Fastidiosa ◽  
Long Chain Fatty Acids ◽  
Powerful Approach ◽  
Diffusible Signal Factor ◽  
Profile Changes ◽  
Olive Quick Decline Syndrome ◽  
Olive Trees

AbstractOlive quick decline syndrome (OQDS) is a disorder associated with bacterial infections caused by Xylella fastidiosa subsp. pauca ST53 in olive trees. Metabolic profile changes occurring in infected olive trees are still poorly investigated, but have the potential to unravel reliable biomarkers to be exploited for early diagnosis of infections. In this study, an untargeted metabolomic method using high-performance liquid chromatography coupled to quadrupole-time-of-flight high-resolution mass spectrometry (HPLC-ESI-Q-TOF-MS) was used to detect differences in samples (leaves) from healthy (Ctrl) and infected (Xf) olive trees. Both unsupervised and supervised data analysis clearly differentiated the groups. Different metabolites have been identified as potential specific biomarkers, and their characterization strongly suggests that metabolism of flavonoids and long-chain fatty acids is perturbed in Xf samples. In particular, a decrease in the defence capabilities of the host after Xf infection is proposed because of a significant dysregulation of some metabolites belonging to flavonoid family. Moreover, oleic acid is confirmed as a putative diffusible signal factor (DSF). This study provides new insights into the host-pathogen interactions and confirms LC-HRMS-based metabolomics as a powerful approach for disease-associated biomarkers discovery in plants. Graphical abstract

scholarly journals Controlling the Spatial Spread of a Xylella Epidemic

2021 ◽  
Vol 83 (4) ◽  
Author(s):  
Sebastian Aniţa ◽  
Vincenzo Capasso ◽  
Simone Scacchi
Keyword(s):  
Spatial Structure ◽  
Numerical Simulations ◽  
Control Strategies ◽  
Xylella Fastidiosa ◽  
Cost Effective ◽  
Olive Tree ◽  
Control Measures ◽  
Weed Biomass ◽  
Spatial Spread ◽  
Olive Trees

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.

scholarly journals Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy)

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Giuseppe Tatulli ◽  
Vanessa Modesti ◽  
Nicoletta Pucci ◽  
Valeria Scala ◽  
Alessia L’Aurora ◽  
...  
Keyword(s):  
Control Strategy ◽  
Xylella Fastidiosa ◽  
In Planta ◽  
Bacterial Concentration ◽  
Infected Area ◽  
Olive Groves ◽  
Term Evaluation ◽  
In Vitro Assessment ◽  
Olive Trees

During recent years; Xylella fastidiosa subsp. pauca (Xfp) has spread in Salento causing relevant damage to the olive groves. Measures to contain the spreading of the pathogen include the monitoring of the areas bordering the so-called “infected” zone and the tree eradication in case of positive detection. In order to provide a control strategy aimed to maintain the tree productivity in the infected areas, we further evaluated the in vitro and in planta mid-term effectiveness of a zinc-copper-citric acid biocomplex. The compound showed an in vitro bactericidal activity and inhibited the biofilm formation in representative strains of X. fastidiosa subspecies, including Xfp isolated in Apulia from olive trees. The field mid-term evaluation of the control strategy assessed by quantitative real-time PCR in 41 trees of two olive groves of the “infected” area revealed a low concentration of Xfp over the seasons upon the regular spraying of the biocomplex over 3 or 4 consecutive years. In particular, the bacterial concentration lowered in July and October with respect to March, after six consecutive treatments. The trend was not affected by the cultivar and it was similar either in the Xfp-sensitive cultivars Ogliarola salentina and Cellina di Nardò or in the Xfp-resistant Leccino. Moreover, the scoring of the number of wilted twigs over the seasons confirmed the trend. The efficacy of the treatment in the management of olive groves subjected to a high pathogen pressure is highlighted by the yielded a good oil production

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