scholarly journals Candidatus Phytoplasma solani (Stolbur phytoplasma).

2021 ◽  
Author(s):  
Fabio Quaglino
Keyword(s):  
Host Plants ◽  
Pathogenic Bacteria ◽  
Eastern Mediterranean ◽  
Control Strategies ◽  
Mediterranean Area ◽  
Plant Diseases ◽  
Cultivated Plants ◽  
Insect Vector ◽  
Insect Vectors ◽  
The European Union

Abstract Phytoplasmas are cell-wall-less plant pathogenic bacteria of the class Mollicutes, which inhabit the phloem sieve tubes of plants and have been associated with several hundred diseases affecting economically important crops. Over the past few decades 'Candidatus Phytoplasma solani', belonging to the 16SrXII-A ribosomal subgroup, has been found to cause a range of plant diseases in different agro-ecosystems in many countries in Europe and the eastern Mediterranean area and a number of others all over the world. It is thought likely that it has always been present, at least in its European range, but has only been noticed in recent years. Diseases caused include bois noir in grapevines, stolbur in tomatoes, potatoes and other wild and cultivated plants, maize redness, lavender decline, and yellowing, reddening, decline, dwarfism, leaf malformation and degeneration diseases of other plants. 'Ca. P. solani' is usually transmitted from plant to plant by the polyphagous insect vector Hyalesthes obsoletus (Cixiidae) which, although it can complete its life cycle on only a small number of plant species, feeds on a much wider range. Recent studies have demonstrated the presence of additional insect vectors of this phytoplasma in Europe, such as Reptalus panzeri in Serbia, possibly R. quinquecostatus in Serbia and France, and Anaceratagallia ribauti in Austria. This scenario highlights the extreme complexity of the ecology of both 'Ca. Phytoplasma solani' and its insect vectors, underlying the difficulty in studying the epidemiology of diseases associated with this pathogen and in developing efficient control strategies. 'Ca. Phytoplasma solani' is also transmitted by parasitic plants and by grafting and vegetative propagation of infected host plants; it can be spread when host plants are transported by people. In the European Union it is listed as a harmful organism necessitating restrictions on the import of plants in the family Solanaceae.

scholarly journals Temporal Dynamics of ‘Ca. Phytoplasma mali’ Load in the Insect Vector Cacopsylla melanoneura

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 592
Author(s):  
Valentina Candian ◽  
Monia Monti ◽  
Rosemarie Tedeschi
Keyword(s):  
Host Plants ◽  
Developmental Stages ◽  
Temporal Dynamics ◽  
Control Strategies ◽  
Vector Competence ◽  
Insect Vector ◽  
Life Stages ◽  
Candidatus Phytoplasma Mali ◽  
High Infection ◽  
Cacopsylla Melanoneura

The transmission of phytoplasmas is the result of an intricate interplay involving pathogens, insect vectors and host plants. Knowledge of the vector’s competence during its lifespan allows us to define more sustainable well-timed control strategies targeted towards the most worrisome life stages. We investigated the temporal dynamics of ‘Candidatus Phytoplasma mali’ load in Cacopsylla melanoneura in the different developmental stages in Northwest Italy. The phytoplasma load in the vector was evaluated in overwintering adults, nymphs and newly emerged adults after different acquisition access periods. Moreover, we followed the multiplication of the phytoplasma during the aestivation and the overwintering period on conifers. Our results confirmed the ability of remigrants to retain the phytoplasma until the end of winter. We also highlighted the high acquisition efficiency and vector competence, based on phytoplasma load, of nymphs and newly emerged adults. Therefore, particular attention should be paid to the management of overwintered C. melanoneura as soon as they return to the orchards, but also to newly emerged adults, particularly in orchards with a high infection rate and when the migration to conifers is delayed.

Real-time PCR assay for distinguishing Frankliniella occidentalis and Thrips palmi Arnika Przybylska, Żaneta Fiedler, Aleksandra Obrępalska-Stęplowska

2017 ◽  
Vol 108 (3) ◽  
pp. 413-420 ◽  
Author(s):  
Arnika Przybylska ◽  
Żaneta Fiedler ◽  
Patryk Frąckowiak ◽  
Aleksandra Obrępalska-Stęplowska
Keyword(s):  
Real Time ◽  
Crop Production ◽  
Frankliniella Occidentalis ◽  
Control Strategies ◽  
Plant Diseases ◽  
The European Union ◽  
Thrips Palmi ◽  
Thrips Species ◽  
Harmful Organisms ◽  
Species Specific

AbstractThrips palmi and Frankliniella occidentalis (order Thysanoptera) are thrips species that represent major plant pests. They are polyphagous insects capable of adversely affecting crop production. As such, in the European Union, these thrips species should be regulated as quarantine organisms. T. palmi and F. occidentalis can cause considerable damage to susceptible plants by feeding on them and transmitting several viruses responsible for serious plant diseases. Successful pest control strategies are based on an early, fast, and reliable diagnosis, which precedes the selection of appropriate steps to limit the effects of harmful organisms. We herein describe a novel diagnostic approach that enables the sensitive and species-specific detection (and differentiation) of these pests in a duplex polymerase chain reaction assay, which was adapted for both standard and real-time quantitative assays. Our method is based on the amplification of a 5.8S-internal transcribed spacer 2 ribosomal DNA fragment that is conserved between T. palmi and F. occidentalis.

scholarly journals Molecular detection and identification of 'Candidatus Liberibacter solanacearum'

Biljni lekar ◽  
2021 ◽  
Vol 49 (1) ◽  
pp. 17-37
Author(s):  
Jelena Menković ◽  
Aleksa Obradović
Keyword(s):  
Host Plants ◽  
Molecular Methods ◽  
Cultivated Plants ◽  
Economic Losses ◽  
Insect Vectors ◽  
Long Distance ◽  
Candidatus Liberibacter Solanacearum ◽  
Detection And Identification ◽  
Geographical Regions ◽  
Candidatus Liberibacter

"Candidatus Liberibacter solanacearum" is a gram-negative, fastidious bacterium that inhabits and multiplies in the phloem of host plants. The bacterium causes economically important diseases of solanaceous crops such as "zebra chips" of potatoes, and chlorotic weakening of cultivated plants of the Apiaceae family. Beside potatotes, this pathogen causes significant economic losses in tobacco, peper and tomato production. Insect vectors classified in the family Triozidae play an important role in the epidemiology of this bacterium. Insects transfer bacterial cells from infected to healthy plants by feeding on the plant juice from the phloem tissue. This pathogenic bacterium could be transmitted by infected seeds which result in long-distance spread. Based on the analysis of single nucleotide polymorphism (SNP), nine haplotypes (A, B, C, D, E, F, G, H, U) from different geographical regions, host plants and insect vectors have been described. Considering to impossibility of isolation of this bacterium on a nutrient medium, detection and identification are based on the application of molecular methods (conventional PCR, real-time PCR, multiplex PCR, nested PCR and LAMP PCR). Taking into consideration the increasing spread of "Candidatus Liberibacter solanacearum" in Europe, as well as its recent detection in Serbia, the aim of this paper was to raise an awareness about importance of this bacterium and summarize the protocols and molecular methods for its detection and identification.

scholarly journals Insect Transmission of Plant Pathogens: a Systems Biology Perspective

mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. e00168-17 ◽  
Author(s):  
Michelle Heck
Keyword(s):  
Systems Biology ◽  
Human Health ◽  
Plant Pathogens ◽  
Control Strategies ◽  
Global Scale ◽  
Pathogen Transmission ◽  
Effective Control ◽  
Insect Vector ◽  
Insect Vectors ◽  
Vector Systems

ABSTRACT Insect-vectored pathogens pose one of the greatest threats to plant and animal, including human, health on a global scale. Few effective control strategies have been developed to thwart the transmission of any insect-transmitted pathogen. Most have negative impacts on the environment and human health and are unsustainable. Plant pathogen transmission by insect vectors involves a combination of coevolving biological players: plant hosts, insect vectors, plant pathogens, and bacterial endosymbionts harbored by the insect. Our ability to help growers to control vector-borne disease depends on our ability to generate pathogen- and/or disease-resistant crops by traditional or synthetic approaches and to block pathogen transmission by the insect vector. Systems biology studies have led to the reexamination of existing paradigms on how pathogens interact with insect vectors, including the bacterial symbionts, and have identified vector-pathogen interactions at the molecular and cellular levels for the development of novel transmission interdiction strategies.

Ticks (Ixodoidea) on migrating birds in Cyprus, fall 1967 and spring 1968, and epidemiological considerations

1974 ◽  
Vol 64 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Makram N. Kaiser ◽  
Harry Hoogstraal ◽  
George E. Watson
Keyword(s):  
Biological Diversity ◽  
Q Fever ◽  
Eastern Mediterranean ◽  
Mediterranean Area ◽  
Wide Distribution ◽  
Sub Saharan Africa ◽  
Boutonneuse Fever ◽  
Ixodes Frontalis ◽  
Haemaphysalis Concinna ◽  
Migrating Birds

AbstractMore or less cursory examination of migrating birds in Cyprus revealed 115 of 2580 southward (fall) migrants and 177 of 22015 northward (spring) migrants to be infested by 167 and 797 ticks, respectively. Most ticks on fall migrants were Hyalomma marginatum marginatum Koch; others were Ixodes frontalis (Panz.), I. ricinus (L.), Haemaphysalis concinna Koch, and H. punctata C. & F., all representative of the Eurasian fauna. Most ticks on spring migrants were H. m. rufipes Koch; others were Amblyomma lepidum Dön., A. nuttalli Dön., and A. variegatum (F.), representative of sub-Saharan Africa, and Argas streptopelia Kaiser, Hoogst. & Horner, Ixodes eldaricus Dzhaparidze, and I. redikorzevi Olen. which probably attached to the hosts in the eastern Mediterranean area. In Africa and Eurasia, 16 arboviruses have been recorded from eight of these tick species, and also the agents of boutonneuse fever, Siberian tick typhus, Q fever, and tularaemia. The epidemiological potential of migrating birds is enhanced by the multiplicity of pathogens that may infect them and the biological diversity of ticks that may infest them. The remarkably wide distribution of Crimean-Congo haemorrhagic fever virus in Africa and Eurasia is likely to be due to intercontinental carriage of the virus and ticks by migrating birds.

scholarly journals Platforms for High-Throughput Screening and Force Measurements on Fungi and Oomycetes

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 639
Author(s):  
Yiling Sun ◽  
Ayelen Tayagui ◽  
Sarah Sale ◽  
Debolina Sarkar ◽  
Volker Nock ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Drug Targets ◽  
Control Strategies ◽  
Pathogenic Fungi ◽  
Antifungal Drugs ◽  
Plant Diseases ◽  
Force Measurements ◽  
Technical Developments ◽  
Alternative Drug

Pathogenic fungi and oomycetes give rise to a significant number of animal and plant diseases. While the spread of these pathogenic microorganisms is increasing globally, emerging resistance to antifungal drugs is making associated diseases more difficult to treat. High-throughput screening (HTS) and new developments in lab-on-a-chip (LOC) platforms promise to aid the discovery of urgently required new control strategies and anti-fungal/oomycete drugs. In this review, we summarize existing HTS and emergent LOC approaches in the context of infection strategies and invasive growth exhibited by these microorganisms. To aid this, we introduce key biological aspects and review existing HTS platforms based on both conventional and LOC techniques. We then provide an in-depth discussion of more specialized LOC platforms for force measurements on hyphae and to study electro- and chemotaxis in spores, approaches which have the potential to aid the discovery of alternative drug targets on future HTS platforms. Finally, we conclude with a brief discussion of the technical developments required to improve the uptake of these platforms into the general laboratory environment.

scholarly journals Rheological profiles in the Central- Eastern Mediterranean

1997 ◽  
Vol 40 (4) ◽  
Author(s):  
M. Viti ◽  
D. Albarello ◽  
E. Mantovani
Keyword(s):  
Heat Flow ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Mediterranean Area ◽  
Geological Time ◽  
Western Turkey ◽  
Geological Time Scale ◽  
Total Strength ◽  
The Mediterranean ◽  
Wet Rocks

Seismological investigations have provided an estimate of the gross structnral features of the crust/upper mantle system in the Mediterranean area. However, this information is only representative of the short-term me- chanical behaviour of rocks and cannot help us to understand slow deformations and related tectonic processes on the geological time scale. In this work strength envelopes for several major structural provinces of the Mediterranean area have been tentatively derived from seismological stratification and heat flow data, on the assumption of constant and uniforrn strain rate (10-16 S-1), wet rocks and conductive geotherm. It is also shown how the uncertainties in the reconstruction of thermal profiles can influence the main rheological prop- erties of the lithosphere, as thickness and total strength. The thickest (50-70 km) and strongest mechanical lithospheres correspond to the coldest zones (with heat flow lower than or equal to 50 mW m-2), i.e., the Io- nian and Levantine mesozoic basins, the Adriatic and Eurasian foreland zones and NW Greece. Heat flows larger than 65 mW m-2, generally observed in extensional zones (Tyrrhenian, Sicily Channel, Northern Aegean, Macedonia and Western Turkey), are mostly related to mechanical lithospheres thinner than 20 km. The characteristics of strength envelopes, and in particular the presence of soft layers in the crust, suggest a reasonable interpretation of some large-scale features which characterize the tectonic evolution of the Central- Eastem Mediterranean.

scholarly journals Ceramic finds from the Byzantine fort of Gradina on the island of Žirje

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ana Karađole ◽  
Igor Borzić
Keyword(s):  
Iron Age ◽  
Eastern Mediterranean ◽  
Mediterranean Area ◽  
The Other ◽  
Late Antique ◽  
North African ◽  
The North ◽  
Other Hand ◽  
Main Production ◽  
Eastern Mediterranean Area

Repeated excavations of the area of the early Byzantine fort on Žirje, an island in the Šibenik archipelago, resulted in recovery of a substantial amount of movable finds, predominantly pottery. Most finds date to the period of Justinian's reconquista in the mid-6th century when the fort was used, but there are also some artifacts of earlier or later dating (Iron Age, Hellenistic and early Imperial periods; medieval and postmedieval periods) whose presence is explained by continuous strategic importance of the fort position. Late antique material has been analyzed comprehensively in terms of typology. Dating and provenance contexts of the finds have also been determined. Presence of pottery from the main production centers that supplied the eastern Adriatic at the time has been attested. This refers in particular to the north African and Aegean-eastern Mediterranean area providing fine tableware and kitchen pottery, lamps and various forms of amphorae. On the other hand, participation of local workshops in supply of the Byzantine soldiers stationed in Gradina probably relates to prevailing forms of kitchenware.

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