scholarly journals Influence of ecological factors on larvae hatching of cystogenous species of nematodes

2016 ◽  
Author(s):  
L. Pylypenko ◽  
K. Kalatur
Keyword(s):  
Control Strategies ◽  
Research Effort ◽  
Inorganic Compounds ◽  
Ecological Factors ◽  
Nematode Species ◽  
Control Measures ◽  
Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Wide Range ◽  
Hatching Process

Understanding hatching process in plant parasitic nematodes has the potential to lead to new control strategies of these devistating pathogens, causing up to10–20% or $80 billion of crop loss globally (Nicol et al, 2011; Каплин, 2012). Although much research effort has been extended in elucidating the hatching factors, there has been no successful control strategy using their analogues to induce hatch in the field. This review examines development on this subject, focusing on the root diffusate, natural and inorganic compounds, as well as abiotic hatching factors (environmental temperature, moisture, aeration). They are assumed to have different impact on the hatching process of various cyst nematodes species despite of similarities in their biological features and life strategies. Notably, soil temperature and moisture play the vital role for species with a wide range of host plants whereas host plant diffusate is a key factor for highly specialized cyst nematode species. Appropriately investigated, it can favour development of control measures specified against targeted nematode species and boost their application in practice.

scholarly journals Marine Organisms for the Sustainable Management of Plant Parasitic Nematodes

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 369
Author(s):  
Pasqua Veronico ◽  
Maria Teresa Melillo
Keyword(s):  
Crop Production ◽  
Control Strategies ◽  
Marine Organisms ◽  
New Drugs ◽  
Effective Control ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Wide Range ◽  
Plant Growth Stimulants ◽  
Plant Parasitic

Plant parasitic nematodes are annually responsible for the loss of 10%–25% of worldwide crop production, most of which is attributable to root-knot nematodes (RKNs) that infest a wide range of agricultural crops throughout the world. Current nematode control tools are not enough to ensure the effective management of these parasites, mainly due to the severe restrictions imposed on the use of chemical pesticides. Therefore, it is important to discover new potential nematicidal sources that are suitable for the development of additional safe and effective control strategies. In the last few decades, there has been an explosion of information about the use of seaweeds as plant growth stimulants and potential nematicides. Novel bioactive compounds have been isolated from marine cyanobacteria and sponges in an effort to find their application outside marine ecosystems and in the discovery of new drugs. Their potential as antihelmintics could also be exploited to find applicability against plant parasitic nematodes. The present review focuses on the activity of marine organisms on RKNs and their potential application as safe nematicidal agents.

scholarly journals Molecular Diversity of Nematode Parasites in Afrotropical Reed Frogs (Hyperolius spp.)

Diversity ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 265
Author(s):  
Ulrich Sinsch ◽  
J. Maximilian Dehling ◽  
Patrick Scheid ◽  
Carsten Balczun
Keyword(s):  
Dna Sequences ◽  
Nematode Species ◽  
Sub Saharan Africa ◽  
Parasitic Nematodes ◽  
Marker Genes ◽  
Nematode Parasites ◽  
Diversity Assessment ◽  
Wide Range ◽  
Nematode Diversity ◽  
Sub Saharan

The diversity of nematodes infecting amphibians is understudied in tropical Africa and unknown in Rwanda. Diversity assessment is hampered by the fact that species descriptions refer mostly to morphological features that are unlinked to DNA sequences of marker genes available in public databases. In this paper, we explore the abundance and diversity of parasitic nematodes in reed frogs Hyperolius kivuensis (n = 115), H. parallelus (n = 45) and H. viridiflavus (n = 100) collected in Rwanda. Five nematode species were identified morphologically as Orneoascaris chrysanthemoides, O. schoutedeni, Gendria leberrei, Aplectana chamaeleonis and Rhabdias collaris. Corresponding DNA sequences of 18S and COI genes were determined and subsequently deposited in GenBank. Aplectana chamaeleonis showed the highest prevalence (8.7%), but O. chrysanthemoides the highest mean intensity of infection (6.0) and largest number (24) of individuals in H. kivuensis. To the best of our knowledge, all amphibian hosts are new records for these nematode species, which are known to infect a wide range of amphibian and reptile species. Our findings suggest that nematode diversity is probably lower than previously assumed due to low host specificity. As morphological species identification is often challenging, our data facilitate molecular identification of adult and specifically larval nematodes found in amphibians of Sub-Saharan Africa.

scholarly journals Morphological and molecular identification of the potato cyst nematodes Globodera rostochiensis and G. pallida in Portuguese potato fields

Nematology ◽  
2017 ◽  
Vol 19 (8) ◽  
pp. 883-889 ◽  
Author(s):  
Maria J. Camacho ◽  
Filomena Nóbrega ◽  
Arlindo Lima ◽  
Manuel Mota ◽  
Maria L. Inácio
Keyword(s):  
Multiplex Pcr ◽  
Molecular Identification ◽  
Diagnostic Technique ◽  
Nematode Species ◽  
Globodera Rostochiensis ◽  
Control Measures ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Widespread Species ◽  
Species Specific

The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida pose one of the greatest threats to potato crops worldwide and are subject to strict quarantine regulations in many countries. The identification of these Globodera species based on morphology may be ambiguous due to the variability of the main morphological features and the overlapping of the standard parameters in these two species; thus, confirmation via molecular methods is recommended. Multiplex PCR with species-specific primers (ITS5/PITSp4 + PITSr3) allows both species to be distinguished. However, despite the development of molecular identification methods, the morphological approach remains useful as a complementary diagnostic technique. In this work, we report results of morphological and molecular analyses that were carried out in two Globodera species from Portuguese potato fields. The average morphometric values of 40 cysts and 40 second-stage juveniles were generally within the expected ranges for G. pallida and G. rostochiensis with some variations noted. Molecular analysis with multiplex PCR confirmed the morphometric identification. The present results confirmed the occurrence of two potato cyst nematode species, G. rostochiensis and G. pallida. Surprisingly, the analysis of soils from Portuguese potato fields detected a greater number of samples infested with G. pallida, which is contrary to expectation as G. rostochiensis has been considered the most widespread species in Portugal. The distinction between the two species is therefore essential in order to detect their presence in the country with a view to re-evaluating the control measures implemented so far and adopting more effective practices.

scholarly journals Community Analysis of Nematodes Associated with Banana, Identification of root knot nematode and Evaluation the Susceptibility of Some Cultivars to Infection

2021 ◽  
Author(s):  
Radwa G. Mostafa ◽  
Aida M. El-Zawahry ◽  
Ashraf E. M. Khalil ◽  
Ameer E. Elfarash ◽  
Ali D. A. Allam
Keyword(s):  
Meloidogyne Javanica ◽  
Nematode Species ◽  
Common Species ◽  
Molecular Techniques ◽  
Control Measures ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Plant Parasitic

Abstract Background Plant-parasitic nematodes are extremely dangerous pests in a variety of economically important crops. The purpose of this study was a survey of all nematode species existing in banana from three sites in Assiut Governorate, Egypt and to characterize the most common species by morphological, morphometric and molecular techniques (PCR with species-specific primers). Then, study of resistance or sensitivity of some banana cultivars to root-knot nematodes.Methods and Results Four nematodes, Meloidogyne, Rotylenchulus reniformis, Helicotylenchus and Pratylenchus were isolated and identified from soil and root samples collected from banana plants. Most frequently occurring of plant parasitic nematode species in banana was Meloidogyne. Former research found differences in species and in resistance to root-knot nematodes among the examined plant cultivars. Identification of Root-knot nematodes by Characterize of morphometric, molecularly, morphological isolate of Meloidogyne related to banana plants. The results revealed that the identified nematode species, Meloidogyne javanica, is the most common plant-parasitic nematodes in all locations. Data on the susceptibility of the tested banana cultivars to M. javanica revealed that Grand Naine was highly susceptible (HS) however, Magraby was susceptible (S) but Williams and Hindi cultivars were moderately resistant (MR).Conclusions we concluded that a survey revealed the significant prevalence of Meloidogyne javanica, the most important nematodes on banana in Assiut. The morphometric, morphological, and molecular identification were harmonic with one another. In addition to the host response of certain banana cultivars, to M. javanica that resistance is of significance and can be helpful to incorporate through planning control measures for root- knot nematodes.

Single juveniles of the potato cyst nematodes Globodera rostochiensis and G. pallida differentiated by randomly amplified polymorphic DNA

Parasitology ◽  
1993 ◽  
Vol 107 (5) ◽  
pp. 567-572 ◽  
Author(s):  
J. Roosien ◽  
P. M. Van Zandvoort ◽  
R. T. Folkertsma ◽  
J. N. A. M. Rouppe Van Der Voort ◽  
A. Goverse ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Rapd Markers ◽  
Random Amplified Polymorphic Dna ◽  
Nematode Species ◽  
Globodera Rostochiensis ◽  
Cyst Nematodes ◽  
Wide Range ◽  
Potential Basis ◽  
Polymerase Chain ◽  
Species Specific

SUMMARYRandom amplified polymorphic DNA (RAPD) offers a potential basis for the development of a diagnostic assay to differentiate the potato cyst nematode species Globodera rostochiensis and G. pallida. Nine decamer primers have been tested for their ability to amplify species-specific DNA sequences. Primer OPG-05 produced 2 discrete DNA fragments, which were consistently present in 5 G. rostochiensis populations and absent in 5 G. pallida populations. These fragments were detectable in single females as well as in single 2nd-stage juveniles. Their amplification is extremely efficient, and reproducible over a wide range of template concentrations. One-fifth of a single juvenile is sufficient to generate reproducible RAPD markers. The amplification from single juveniles requires no DNA isolation. The use of a crude homogenate does not impair the polymerase chain reaction.

Effects of plant phenylpropanoid pathway products and selected terpenoids and alkaloids on the behaviour of the plant-parasitic nematodes Radopholus similis, Pratylenchus penetrans and Meloidogyne incognita

Nematology ◽  
2006 ◽  
Vol 8 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Nathalie Wuyts ◽  
Rony Swennen ◽  
Dirk De Waele
Keyword(s):  
Meloidogyne Incognita ◽  
Chemical Defence ◽  
Nematode Species ◽  
Biologically Active ◽  
Parasitic Nematodes ◽  
Pratylenchus Penetrans ◽  
Radopholus Similis ◽  
Irreversible Inhibitor ◽  
Wide Range

AbstractPlants produce a wide range of biologically active chemicals which have been extensively explored for nematode-antagonistic properties. Although phenylpropanoids are part of the chemical defence system of plants against pests and diseases, including parasitic nematodes, no comprehensive study exists which relates (levels of) phenylpropanoid compounds in roots to actual effects on nematode behaviour. Therefore, a broad spectrum evaluation was made of the effects of phenylpropanoids (simple phenolics and flavonoids) and selected monoterpenoids and alkaloids on the behaviour of the migratory endoparasites Radopholus similis and Pratylenchus penetrans and the sedentary endoparasite Meloidogyne incognita. In vitro bioassays assessed effects on chemotaxis, motility, viability and hatch. Compared with the other two nematode species, P. penetrans was remarkably insensitive to the test compounds. Only phloretin was (limited) hatch inhibitive. This property was shared by other chalcone-related compounds for R. similis. Repellents and motility inhibitors for R. similis and M. incognita were found among the simple phenolic compounds. Flavonols stood out as repellent compounds for both these nematode species, while they were, in their degraded form, also motility inhibitors for M. incognita. Dopamine was an attractant for R. similis, while ferulic acid was strongly motility inhibitive and toxic (LC50 of 120 μg ml−1) for this nematode species. Salicylic acid was a strong attractant for M. incognita. The compound was also nematicidal (LC50 of 46 μg ml−1) and an irreversible inhibitor of hatch.

scholarly journals Pratylenchus vovlasi sp. Nov. (Nematoda: Pratylenchidae) on Raspberries in North Italy with a Morphometrical and Molecular Characterization

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1068
Author(s):  
Alberto Troccoli ◽  
Elena Fanelli ◽  
Pablo Castillo ◽  
Gracia Liébanas ◽  
Alba Cotroneo ◽  
...  
Keyword(s):  
Its Region ◽  
Nematode Species ◽  
Integrative Taxonomy ◽  
Integrative Approach ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Root Lesion Nematode ◽  
Cyst Nematodes ◽  
Lesion Nematode

Root-lesion nematode species rank third only to root-knot and cyst nematodes as having the greatest economic impact on crops worldwide. A survey of plant-parasitic nematodes associated with decaying raspberries (Rubus sp.) in northern Italy revealed that root-lesion nematodes were the most frequently occurring species among other phytonematodes. Several Pratylenchus species have been associated with Rubus sp. in Canada (Quebec, British Columbia) and USA (North Carolina, Maryland, New Jersey) including P. penetrans and P. crenatus. In the roots and rhizosphere of symptomatic raspberries, nematodes of two Pratylenchus spp. were detected. Detailed morphometrics of the two root-lesion nematode isolates were consistent with Pratylenchus crenatus and with an undescribed Pratylenchus species. The extracted nematodes were observed and measured as live and fixed materials and subsequently identified by integrative taxonomy (morphometrically and molecularly). The latter species is described herein as Pratylenchus vovlasi sp. nov., resulting morphometrically closest to P. mediterraneus and phylogenetically to P. pratensis. The molecular identification of Pratylenchus vovlasi sp. nov. was carried out by sequencing the ITS region, D2-D3 expansion domains of the 28S rRNA gene and a partial region of the nuclear hsp90 gene. ITS-RFLP and sequence analyses revealed that Pratylenchus vovlasi sp. nov. had species-specific restriction profiles with no corresponding sequences present in the database. The phylogenetic relationships with ITS and D2-D3 sequences placed the Pratylenchus vovlasi sp. nov. in a clade with P. pratensis and P. pseudopratensis. This research confirms the occurrence of cryptic biodiversity within the genus Pratylenchus as well as the need for an integrative approach to the identification of Pratylenchus species.

scholarly journals The narrow-spectrum anthelmintic oxantel is a potent agonist of a novel acetylcholine receptor subtype in whipworms

2021 ◽  
Vol 17 (2) ◽  
pp. e1008982
Author(s):  
Tina V. A. Hansen ◽  
Susanna Cirera ◽  
Cédric Neveu ◽  
Elise Courtot ◽  
Claude L. Charvet ◽  
...  
Keyword(s):  
Acetylcholine Receptor ◽  
Animal Health ◽  
High Sensitivity ◽  
Nematode Species ◽  
Screening Tools ◽  
Parasitic Nematodes ◽  
Receptor Subtype ◽  
Narrow Spectrum ◽  
Wide Range ◽  
Free Living Nematode

In the absence of efficient alternative strategies, the control of parasitic nematodes, impacting human and animal health, mainly relies on the use of broad-spectrum anthelmintic compounds. Unfortunately, most of these drugs have a limited single-dose efficacy against infections caused by the whipworm, Trichuris. These infections are of both human and veterinary importance. However, in contrast to a wide range of parasitic nematode species, the narrow-spectrum anthelmintic oxantel has a high efficacy on Trichuris spp. Despite this knowledge, the molecular target(s) of oxantel within Trichuris is still unknown. In the distantly related pig roundworm, Ascaris suum, oxantel has a small, but significant effect on the recombinant homomeric Nicotine-sensitive ionotropic acetylcholine receptor (N-AChR) made up of five ACR-16 subunits. Therefore, we hypothesized that in whipworms, a putative homolog of an ACR-16 subunit, can form a functional oxantel-sensitive receptor. Using the pig whipworm T. suis as a model, we identified and cloned a novel ACR-16-like subunit and successfully expressed the corresponding homomeric channel in Xenopus laevis oocytes. Electrophysiological experiments revealed this receptor to have distinctive pharmacological properties with oxantel acting as a full agonist, hence we refer to the receptor as an O-AChR subtype. Pyrantel activated this novel O-AChR subtype moderately, whereas classic nicotinic agonists surprisingly resulted in only minor responses. We observed that the expression of the ACR-16-like subunit in the free-living nematode Caenorhabditis elegans conferred an increased sensitivity to oxantel of recombinant worms. We demonstrated that the novel Tsu-ACR-16-like receptor is indeed a target for oxantel, although other receptors may be involved. These finding brings new insight into the understanding of the high sensitivity of whipworms to oxantel, and highlights the importance of the discovery of additional distinct receptor subunit types within Trichuris that can be used as screening tools to evaluate the effect of new synthetic or natural anthelmintic compounds.

Differential chemotactic responses of two plant-parasitic nematodes, Meloidogyne incognita and Rotylenchulus reniformis, to some inorganic ions

Nematology ◽  
2002 ◽  
Vol 4 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Patrick Quénéhervé ◽  
Ronan Le Saux
Keyword(s):  
Meloidogyne Incognita ◽  
Control Strategies ◽  
Inorganic Ions ◽  
Nematode Species ◽  
Ammonium Salts ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Rotylenchulus Reniformis ◽  
Chloride Salts ◽  
Plant Parasitic

AbstractThe orientation of juveniles of Meloidogyne incognita and Rotylenchulus reniformis was studied in salt gradients created in a linear agarose gel. Twelve combinations of calcium, potassium, sodium or ammonium cations and chloride, nitrate or sulphate anions were tested. The orientation of juveniles of M. incognita was induced by the constitutive cation of the salt, e.g., calcium salts had no effect while the other salts and especially ammonium salts and ammonium nitrate were strongly repellent. In contrast, the orientation of juveniles of R. reniformis was induced by the constitutive anion of the salt, e.g., chloride salts were found to be repellent while sulphate and nitrate salts were attractive. These results are discussed as possible novel control strategies for economically important plant parasitic nematodes. In other respects, these differences in chemical preferences may partly explain the observed geographical distribution of these nematode species according to the ionic content of the soils.

Decline of Pratylenchus coffeae and Radopholus arabocoffeae populations after death and removal of 5-year-old arabica coffee (Coffea arabica cv. Catimor) trees

Nematology ◽  
2011 ◽  
Vol 13 (4) ◽  
pp. 491-500 ◽  
Author(s):  
Chau Nguyen ◽  
Maurice Moens ◽  
Wim Wesemael ◽  
Phap Trinh
Keyword(s):  
Coffea Arabica ◽  
Nematode Species ◽  
Soil Samples ◽  
Control Measures ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Arabica Coffee ◽  
Soil Layers ◽  
Pratylenchus Coffeae ◽  
Coffee Plants

AbstractThe decline of populations of the plant-parasitic nematodes Radopholus arabocoffeae and Pratylenchus coffeae was studied after the death and removal of severely damaged coffee plants (Coffea arabica cv. Catimor) in a field naturally infested with both nematodes. Soil samples were taken at monthly intervals up to a depth of 70 cm and divided into 10 cm segments from which nematodes were extracted. The numbers of R. arabocoffeae and P. coffeae in soil and in root fragments were determined. Both species were found up to 70 cm depth. Densities of R. arabocoffeae and P. coffeae populations declined exponentially over time in all soil layers. No nematodes were found in soil and root fragments 10 and 11 months after removal of the infected coffee plants for R. arabocoffeae and P. coffeae, respectively. Arabica coffee seedlings were planted in soil collected from the experimental plots after these time periods. The seedlings were grown for 3 months in a glasshouse and then roots and soil were analysed for presence of both nematode species. No R. arabocoffeae and P. coffeae were found, confirming that the population in the field had completely declined. The results of this experiment demonstrate that a replant of coffee is possible 1 year after removal of infected plants from a plantation without any further (chemical) control measures.

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