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Sample records for reniform nematode management

  1. Use of slaughterhouse waste and tannery-based organic compost for management of reniform nematode

    Directory of Open Access Journals (Sweden)

    Guilherme L. Asmus

    2014-07-01

    Full Text Available A greenhouse experiment was carried out with the objective of evaluating the effect of increasing soil amendments (1, 3, 9, 15 and 30%, v/v of organic compost produced from slaughterhouse waste and tannery residues on the reproduction of reniform nematodes and cotton development. The addition of organic composts to soil proportionately reduced the number of nematodes per gram of root and the reproduction factor. However, depending on the concentration of the compost, there was a reduction of height and dry mass of cotton shoots. We concluded that the organic compost produced with slaughterhouse and tannery waste has potential for controlling reniform nematodes, but requires dose adjustments or improvements in its composition to reduce the risk of phytotoxicity.

  2. Soybean lines evaluated for resistance to reniform nematode

    Science.gov (United States)

    Seventy-four wild and domestic soybean (Glycine max and G. soja) lines were evaluated for resistance to reniform nematode (Rotylenchulus reniformis) in growth chamber tests with a day length of 16 hours and temperature held constant at 28 C. Several entries for which reactions to reniform nematode w...

  3. Product evaluation for reniform nematode suppression in Mississippi Delta sweetpotato production, 2011

    Science.gov (United States)

    The reniform nematode, Rotylenchulus reniformis, can cause significant losses in sweetpotato, Ipomoea batatas, production in the Mississippi Delta. Reniform nematode is a microscopic plant parasite that feeds on sweetpotato roots causing severe stunting of root growth. Reduction in yield due to the ...

  4. Transcriptome Analysis of Cotton (Gossypium hirsutum L. Genotypes That Are Susceptible, Resistant, and Hypersensitive to Reniform Nematode (Rotylenchulus reniformis.

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    Ruijuan Li

    Full Text Available Reniform nematode is a semi-endoparasitic nematode species causing significant yield loss in numerous crops, including cotton (Gossypium hirsutum L.. An RNA-sequencing analysis was conducted to measure transcript abundance in reniform nematode susceptible (DP90 & SG747, resistant (BARBREN-713, and hypersensitive (LONREN-1 genotypes of cotton (Gossypium hirsutum L. with and without reniform nematode infestation. Over 90 million trimmed high quality reads were assembled into 84,711 and 80, 353 transcripts using the G. arboreum and the G. raimondii genomes as references. Many transcripts were significantly differentially expressed between the three different genotypes both prior to and during nematode pathogenesis, including transcripts corresponding to the gene ontology categories of cell wall, hormone metabolism and signaling, redox reactions, secondary metabolism, transcriptional regulation, stress responses, and signaling. Further analysis revealed that a number of these differentially expressed transcripts mapped to the G. raimondii and/or the G. arboreum genomes within 1 megabase of quantitative trait loci that had previously been linked to reniform nematode resistance. Several resistance genes encoding proteins known to be strongly linked to pathogen perception and resistance, including LRR-like and NBS-LRR domain-containing proteins, were among the differentially expressed transcripts mapping near these quantitative trait loci. Further investigation is required to confirm a role for these transcripts in reniform nematode susceptibility, hypersensitivity, and/or resistance. This study presents the first systemic investigation of reniform nematode resistance-associated genes using different genotypes of cotton. The candidate reniform nematode resistance-associated genes identified in this study can serve as the basis for further functional analysis and aid in further development of reniform a nematode resistant cotton germplasm.

  5. Principal Component Analysis and Molecular Characterization of Reniform Nematode Populations in Alabama

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    Seloame T. Nyaku

    2016-04-01

    Full Text Available U.S. cotton production is suffering from the yield loss caused by the reniform nematode (RN, Rotylenchulus reniformis. Management of this devastating pest is of utmost importance because, no upland cotton cultivar exhibits adequate resistance to RN. Nine populations of RN from distinct regions in Alabama and one population from Mississippi were studied and thirteen morphometric features were measured on 20 male and 20 female nematodes from each population. Highly correlated variables (positive in female and male RN morphometric parameters were observed for body length (L and distance of vulva from the lip region (V (r = 0.7 and tail length (TL and c′ (r = 0.8, respectively. The first and second principal components for the female and male populations showed distinct clustering into three groups. These results show pattern of sub-groups within the RN populations in Alabama. A one-way ANOVA on female and male RN populations showed significant differences (p ≤ 0.05 among the variables. Multiple sequence alignment (MSA of 18S rRNA sequences (421 showed lengths of 653 bp. Sites within the aligned sequences were conserved (53%, parsimony-informative (17%, singletons (28%, and indels (2%, respectively. Neighbor-Joining analysis showed intra and inter-nematodal variations within the populations as clone sequences from different nematodes irrespective of the sex of nematode isolate clustered together. Morphologically, the three groups (I, II and III could not be distinctly associated with the molecular data from the 18S rRNA sequences. The three groups may be identified as being non-geographically contiguous.

  6. Transcript Analysis of Sedentary Parastic Female Reniform Nematodes (Rotylenchulus reniformis) Identifies Candidate Parasitism Genes and Targets for RNA-Interference

    Science.gov (United States)

    The reniform nematode (RN) (Rotylenchulus reniformis) is a semi-endoparasitic nematode with a host range that spans 30 plant families; however, RN infection is particularly detrimental to Upland cotton (Gossypium hirsutum). We present here an initial survey of cDNA sequences isolated from the RN fe...

  7. Multiple nodulation genes are up-regulated during establishment of reniform nematode feeding sites in soybean.

    Science.gov (United States)

    Redding, Nathan Wayne; Agudelo, Paula; Wells, Christina E

    2017-09-15

    The semi-endoparastic reniform nematode (Rotylenchulus reniformis) infects over 300 plant species. Females penetrate host roots and induce formation of complex, multinucleate feeding sites called syncytia. While anatomical changes associated with reniform nematode infection are well documented, little is known about their molecular basis. We grew soybean (Glycine max) in a split-root growth system, inoculated half of each root system with R. reniformis, and quantified gene expression in infected and control root tissue at four dates after inoculation. Over 6,000 genes were differentially expressed between inoculated and control roots on at least one date (FDR = 0.01, |log2FC| ≥ 1), and 507 gene sets were significantly enriched or depleted in inoculated roots (FDR = 0.05). Numerous genes up-regulated during syncytium formation had previously been associated with rhizobia nodulation. These included the nodule-initiating transcription factors CYCLOPS, NSP1, NSP2, and NIN, as well as multiple nodulins associated with the plant-derived peribacteroid membrane. Nodulation-related NIP aquaporins and SWEET sugar transporters were induced, as were plant CLAVATA3/ESR-related (CLE) signaling proteins and cell cycle regulators such as CCS52A and E2F. Nodulins and nodule-associated genes may have ancestral functions in normal root development and mycorrhization that have been co-opted by both parasitic nematodes and rhizobial bacteria to promote feeding site and nodule formation.

  8. Reniform nematode (Rotylenchulus reniformis) resistance locus from Gossypium aridum identified and introgressed into upland cotton (G. hirsutum)

    Science.gov (United States)

    SSR markers associated with reniform nematode (Rotylenchulus reniformis) resistance were identified and mapped using progeny from a cross between a tri-species hybrid [Gossypium arboreum × (G 371 - G. hirsutum × G. aridum -)] and G. hirsutum MD51ne. The 50 most resistant and 26 most susceptible prog...

  9. Efficiency of green manure species on the population of reniform nematode

    Directory of Open Access Journals (Sweden)

    Cristiane Gonçalves Gardiano

    2014-02-01

    Full Text Available The objective of this study was to evaluate the growing of soil improving crops on the population of Rotylenchulus reniformis in naturally infested soil. It was evaluated the effect of 6 species of plants as cover crops in winter and 13 summer species and a fallow treatment on the nematode population under greenhouse. After 60 days, the root system was collected. Then, a sample of soil was taken in order to extract juveniles from the soil and quantification the final population of the pathogen in each pot for determining of the reproduction factor (RF. Fallow and all winter species of green manure, except hairy vetch, reduced the population of R. reniformis after cultivation in infested soil, in comparison to the control. Regarding summer cover crops, it was observed that sorghum ‘SI03204’ (Sorghum vulgare, millet ‘BRS1501’ (Pennisetum glaucum, Brachiaria ruziziensis, finger millet (Eleusine coracana, estylo ‘Campo Grande’ (Stylosanthes capitata x S. macrocephala, peanut ‘IAC Tatu ST’ (Arachis hypogaea and dwarf velvet bean (Mucuna deeringiana reduced the population of R. reniformis, when compared to the control, could be used in the management of this nematode.

  10. Sequence and Spatiotemporal Expression Analysis of CLE-Motif Containing Genes from the Reniform Nematode (Rotylenchulus reniformis Linford & Oliveira).

    Science.gov (United States)

    Wubben, Martin J; Gavilano, Lily; Baum, Thomas J; Davis, Eric L

    2015-06-01

    The reniform nematode, Rotylenchulus reniformis, is a sedentary semi-endoparasitic species with a host range that encompasses more than 77 plant families. Nematode effector proteins containing plant-ligand motifs similar to CLAVATA3/ESR (CLE) peptides have been identified in the Heterodera, Globodera, and Meloidogyne genera of sedentary endoparasites. Here, we describe the isolation, sequence analysis, and spatiotemporal expression of three R. reniformis genes encoding putative CLE motifs named Rr-cle-1, Rr-cle-2, and Rr-cle-3. The Rr-cle cDNAs showed >98% identity with each other and the predicted peptides were identical with the exception of a short stretch of residues at the carboxy(C)-terminus of the variable domain (VD). Each RrCLE peptide possessed an amino-terminal signal peptide for secretion and a single C-terminal CLE motif that was most similar to Heterodera CLE motifs. Aligning the Rr-cle cDNAs with their corresponding genomic sequences showed three exons with an intron separating the signal peptide from the VD and a second intron separating the VD from the CLE motif. An alignment of the RrCLE1 peptide with Heterodera glycines and Heterodera schachtii CLE proteins revealed a high level of homology within the VD region associated with regulating in planta trafficking of the processed CLE peptide. Quantitative RT-PCR (qRT-PCR) showed similar expression profiles for each Rr-cle transcript across the R. reniformis life-cycle with the greatest transcript abundance being in sedentary parasitic female nematodes. In situ hybridization showed specific Rr-cle expression within the dorsal esophageal gland cell of sedentary parasitic females.

  11. Induction of pathogenesis-related gene 1 (PR-1 by acibenzolar-s-methyl application in pineapple and its effect on reniform nematodes (Rotylenchulus reniformis

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    Buncha Chinnasri

    2016-09-01

    Full Text Available The induction of systemic acquired resistance (SAR in pineapples (Ananas comosus was studied as shown by the up-regulation of the PR-1 gene (the SAR marker and examination of the SAR effect on the reniform nematode, Rotylenchulus reniformis. Real-time polymerase chain reaction assay was performed using degenerate primers designed from the PR-1 genes of several monocotyledonous (monocots and dicotyledonous (dicots plants. A 266 bp cDNA band was evident only in plants treated with the SAR inducer, acibenzolar-s-methyl. This 266 bp cDNA was sequenced and found to be highly homologous to a number of PR-1 genes from monocots. In addition, the amino acid sequence deduced from the 266 bp cDNA showed a high identity to PR-1 proteins from both monocots and dicots. Therefore, it was highly likely that this cloned fragment was part of the A. comosus PR-1 gene, indicating that A. comosus has an SAR pathway. The time course of PR-1 expression was studied. The results showed that PR-1 induction was initiated as early as 1 d after acibenzolar application and continued through 3 wk thereafter. The effect of SAR on the nematodes, R. reniformis, in pineapples was also elucidated. The results showed that the reproduction of nematodes on the pineapples treated with 100 mg/L or 200 mg/L was 55% lower than that on pineapples treated with 0 mg/L or 50 mg/L. Nematode reproduction on pineapples treated with the same concentration but inoculated at different times was not significantly different (p > 0.05.

  12. Occurrence and identification of reniform nematode disease of banana seedling%香蕉假植苗肾形线虫病的发生与病原鉴定

    Institute of Scientific and Technical Information of China (English)

    周峡; 张锦恒; 张绍升

    2012-01-01

    据调查,福建省漳州市香蕉组培假植苗普遍遭受肾形线虫侵染.通过观察形态特征,该病原线虫被鉴定为肾状肾形线虫,这是国内首次发现该线虫侵染香蕉组培假植苗.肾形线虫以未成熟雌虫侵染香蕉幼嫩的根组织,虫体前部插入皮层取食,后部在根组织外发育肥大;香蕉肾形线虫成熟雌虫通常为半内寄生,有时完全埋生于根组织内;受侵染的香蕉假植苗根系萎缩、变黑腐烂,地上部植株矮小、生长不良.%Investigation of disease on banana seedling in Zhangzhou, Fujian showed.that banana seedling was seriously infected by reniform nematode. The pathogenetic nematode was identified as Rotylenchulus reniformis based on morphological characteristics, and banana seedling infected by R. reniformis was first reported in China. Immature female was the infective stage of reniforra nematode. On penetration, only the anterior part of the body embedded within the cortical tissue of root, and the posterior part of the body swelled to form a typical kidney-shape out of the root tissue; the mature female of R. reniformis on banana was semi-endoparasite, but sometimes, it could be completely wrapped in root tissue; the infected root of banana seedling was atrophic, black and rotton, and aboveground of the plant was stunted and hypogenetic.

  13. Developing sustainable systems for nematode management.

    Science.gov (United States)

    Barker, K R; Koenning, S R

    1998-01-01

    Early researchers identified key concepts and developed tactics for multiple-option management of nematodes. Although the emphasis on integrated pest management over the past three decades has promoted strategies and tactics for nematode management, comprehensive studies on the related soil biology-ecology are relatively recent. Traditional management tactics include host resistance (where available), cultural tactics such as rotation with nonhosts, sanitation and avoidance, and destruction of residual crop roots, and the judicious use of nematicides. There have been advances in biological control of nematodes, but field-scale exploitation of this tactic remains to be realized. New technologies and resources are currently becoming central to the development of sustainable systems for nematode-pest-crop management: molecular diagnostics for nematode identification, genetic engineering for host resistance, and the elucidation and application of soil biology for general integrated cropping systems. The latter strategy includes the use of nematode-pest antagonistic cover crops, animal wastes, and limited tillage practices that favor growth-promoting rhizobacteria, earthworms, predatory mites, and other beneficial organisms while suppressing parasitic nematodes and other plant pathogens. Certain rhizobacteria may induce systemic host resistance to nematodes and, in some instances, to foliage pathogens. The systems focusing on soil biology hold great promise for sustainable crop-nematode management, but only a few research programs are currently involved in this labor-intensive endeavor.

  14. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    OpenAIRE

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management.

  15. Biocontrol: the potential of entomophilic nematodes in insect management.

    Science.gov (United States)

    Webster, J M

    1980-10-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management.

  16. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    OpenAIRE

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management.

  17. Taxonomic status of Pelargonium reniforme Curt.

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    Janine E. Victor

    2014-07-01

    Full Text Available Background: Pelargonium reniforme Curt. is a morphologically variable species that many authors have attempted to split or combine. Confusion relating to the differences between the two subspecies currently included under P. reniforme has impeded attempts to assess their conservation status.  Pelargonium reniforme is closely related to  Pelargonium sidoides;  the two species are indistinguishable when not flowering and their distributions overlap in some areas.Objectives: With this study, we aimed to clarify the taxonomic status of the two subspecies of P. reniforme, which has relevance in terms of their conservation status.Method: Leaf shape, petiole length, internode length and flower colour were assessed by studying herbarium specimens of the two subspecies of  P. reniforme and specimens of P. sidoides. Living specimens of the two subspecies were also examined in their natural habitat.Results: The current investigation showed that the morphological characters used to distinguish the two subspecies of P. reniforme are too variable to separate them. Variation in some morphological characters may be related to environmental conditions.Conclusion: The recognition of the two subspecies of P. reniforme as distinct taxa is no longer justified.

  18. Phenotypic and molecular evaluation of cotton hairy roots as a model system for studying nematode resistance

    Science.gov (United States)

    The cellular mechanisms that mediate resistance of allotetraploid cotton (Gossypium spp.) to root-knot nematode (Meloidogyne incognita) and reniform nematode (Rotylenchulus reniformis) are poorly understood. Here, Agrobacterium rhizogenes-induced hairy roots were investigated as a possible research...

  19. Organic amendments and their influences on plant-parasitic and free-living nematodes: a promising method for nematode management?

    NARCIS (Netherlands)

    Thoden, T.C.; Korthals, G.W.; Termorshuizen, A.J.

    2011-01-01

    The use of organic soil amendments, such as green manures, animal manures, composts or slurries, certainly has many advantageous aspects for soil quality and is suggested as a promising tool for the management of plant-parasitic nematodes. However, during a recent literature survey we also found num

  20. Site-Specific Detection and Management of Nematodes

    Science.gov (United States)

    Nematode distribution varies significantly throughout a field and is highly correlated to soil texture and other edaphic factors. Field-wide application results in nematicides being applied to areas without nematodes and the application of sub-effective levels in areas with high nematode densities. ...

  1. Transcript Analysis of Parasitic Females of the Sedentary Semi-Endoparasitic Nematode Rotylenchulus reniformis

    Science.gov (United States)

    The reniform nematode, Rotylenchulus reniformis Linford & Oliveira, is a sedentary semi-endoparasitic roundworm that infects the roots of many economically important plant species. Engineered resistance to plant-parasitic nematodes (PPNs) via RNA-interference (RNAi) has shown promise in providing h...

  2. Integrated management of root-knot nematode, Meloidogyne incognita infestation in tomato and grapevine.

    Science.gov (United States)

    Kumari, N Swarna; Sivakumar, C V

    2005-01-01

    An integrated approach with the obligate bacterial parasite, Pasteuria penetrans and nematicides was assessed for the management of the root-knot nematode, Meloidogyne incognita infestation in tomato and grapevine. Seedlings of tomato cv. Co3 were transplanted into pots filled with sterilized soil and inoculated with nematodes (5000 juveniles/pot). The root powder of P. penetrans at 10 mg/pot was applied alone and in combination with carbofuran at 6 mg/pot. Application of P. penetrans along with carbofuran recorded lowest nematode infestation (107 nematodes/200 g soil) compared to control (325 nematodes/200 g soil). The rate of parasitization was 83.1% in the carbofuran and P. penetrans combination treatment as against 61.0% in the P. penetrans treatment only. The plant growth was also higher in the combination treatment compared to all other treatments. A field trial was carried out to assess the efficacy of P. penetrans and nematicides viz., carbofuran and phorate in the management of root-knot nematode, M. incognita infestation of grapevine cv. Muscat Hamburg. A nematode and P. penetrans infested grapevine field was selected and treatments either with carbofuran or phorate at 1 g a.i/vine was given. The observations were recorded at monthly interval. The results showed that the soil nematode population was reduced in nematicide treated plots. Suppression of nematodes was higher under phorate (117 nematodes/200 g soil) than under carbofuran (126.7 nematodes/200 g soil) treatment. The number of juveniles parasitized was also influenced by nematicides and spore load carried/juvenile with phorate being superior and the increase being 17.0 and 29.0% respectively over the control. The results of these experiment confirmed the compatibility of P. penetrans with nematicides and its biological control potential against the root-knot nematode.

  3. Integrated management of root-knot nematode (Meloidogyne ...

    African Journals Online (AJOL)

    (p<0.05) the nematode egg hatching as well as juvenile motility over the untreated control. Higher ... the pot house experiment. .... and placed to a drop of glycerine on a clean glass slide with ... knot nematode for subsequent experiments in the.

  4. Statistical and Economic Techniques for Site-specific Nematode Management.

    Science.gov (United States)

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L

    2014-03-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes.

  5. Managing Plant-Parasitic Nematodes in Established Red Raspberry Fields

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    The efficacy and phytotoxicity of post-plant treatments to control root lesion [Pratylenchus penetrans (Cobb), Chitwood & Otiefa] and dagger (Xiphinema bakeri Williams) nematodes in red raspberry (Rubus idaeus L.) were evaluated in four field studies conducted over three years. Spring spray applicat...

  6. Rootstock assessment for root-knot nematode management in grafted honeydew melon

    Science.gov (United States)

    Root-knot nematodes (RKN) are one of the most damaging soilborne pathogens of honeydew melon (Cucumis melo var. inodorus). Currently their management is dependent on soil fumigation. Vegetable grafting with resistant rootstocks may be an effective approach for RKN management in the sustainable produ...

  7. Biogeography of Parasitic Nematode Communities in the Galapagos Giant Tortoise: Implications for Conservation Management.

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    Guillaume Fournié

    Full Text Available The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

  8. Economic modelling of grazing management against gastrointestinal nematodes in dairy cattle

    NARCIS (Netherlands)

    Voort, van der M.; Meensel, Van J.; Lauwers, L.; Haan, de M.H.A.; Evers, A.G.; Huylenbroeck, Van G.; Charlier, J.

    2017-01-01

    Grazing management (GM) interventions, such as reducing the grazing time or mowing pasture before grazing, have been proposed to limit the exposure to gastrointestinal (GI) nematode infections in grazed livestock. However, the farm-level economic effects of these interventions have not yet been asse

  9. Nematode communities of natural and managed beech forests - a pilot study

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Madsen, Mette Vestergård; Johansson, Sanne

    2002-01-01

    forests is discussed. We suggest dead wood input to be the driving variable leading to the observed differences in the nematode community between managed and natural forests of Zealand, Denmark. The marked site differences found in this study emphasizes the need to carefully choose reference areas where...

  10. Soil nematode responses to crop management and conversion to native grasses.

    Science.gov (United States)

    Briar, Shabeg S; Barker, Corinne; Tenuta, Mario; Entz, Martin H

    2012-09-01

    Soil nematode community response to treatments of three, four-year crop rotations (spring wheat-pea-spring wheat-flax, spring wheat-green manure-spring wheat-flax, and spring wheat-alfalfa-alfalfa-flax) under conventional and organic management, and native tall grass restoration (restored prairie) were assessed in June 2003, and July and August 2004. The research site was the Glenlea Long-term Rotation and Crop Management Study, in the Red River Valley, Manitoba, established in 1992. The nematode community varied more with sample occasion than management and rotation. The restored prairie favored high colonizer-persister (c-p) value omnivores and carnivores, and fungivores but less bacterivores. The restored prairie soil food web was highly structured, mature and low-to-moderately enriched as indicated by structure (SI), maturity (MI) and enrichment (EI) index values, respectively. Higher abundance of fungivores and channel index (CI) values suggested fungal-dominated decomposition. Nematode diversity was low even after more than a decade of restoration. A longer time may be required to attain higher diversity for this restored fragmented prairie site distant from native prairies. No consistent differences were found between organic and conventional management for nematode trophic abundance, with the exception of enrichment opportunists of the c-p 1 group which were favored by conventional management. Although EI was lower and SI was higher for organic than conventional their absolute values suggested decomposition channels to be primarily bacterial, and fewer trophic links with both management scenarios. A high abundance of fungivores in the rotation including the green manure indicates greater fungal decomposition.

  11. Remote Sensing of Parasitic Nematodes in Plants

    Science.gov (United States)

    Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John

    2007-01-01

    A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.

  12. Spatial distribution of nematodes in three banana ( Musa AAA) root parts considering two root thickness in three farm management systems

    Science.gov (United States)

    Araya, M.; De Waele, D.

    2004-10-01

    The spatial location of the banana ( Musa AAA) root parasitic nematodes within three root parts considering two root thickness was determined in three commercial farm management systems, which differ in weed and nematode management. Roots in each farm management system were classified in thick (>5 mm-d) and thin (1 ≤ 5 mm-d) roots. From each root type, the epidermis, the cortical parenchyma (CP) and the vascular cylinder (VC) were separated by fingernail, and nematodes were extracted by maceration of each root part. Independent of the farm management system, and for either root thickness, highest numbers of Radopholus similis per gram of root was found in the CP, followed by the epidermis and VC. The highest number of Helicotylencus spp., Pratylenchus spp. and the total nematode population per gram of root was found in the epidermis. Considering the number of nematodes per root part, the highest number of R. similis and total nematodes was located in the CP, while Helicotylenchus spp. and Pratylenchus spp. were concentrated in the epidermis. These patterns were approximately reproduced in the two root thickness and in the three farm management systems. This behavior suggests that injection of systemic nematicides into the plant pseudostem to replace the granular applications on surface soil might be promissory.

  13. Biological control potential of entomopathogenic nematodes for management of Caribbean fruit fly, Anastrepha suspensa Loew (Tephritidae).

    Science.gov (United States)

    Heve, William K; El-Borai, Fahiem E; Carrillo, Daniel; Duncan, Larry W

    2017-06-01

    Caribbean fruit fly (Caribfly) is a serious economic insect pest because of development of larvae that hatch from eggs oviposited into fruits by female adults. This study assessed the virulence of twelve entomopathogenic nematode (EPN) isolates to Caribfly in laboratory bioassays as a starting point toward evaluation of management strategies for the fruit-to-soil-dwelling stages of A. suspensa in fields infested by Caribfly. Inoculation of A. suspensa with 1 mL of ca 200 IJs larva(-1) killed Caribfly at either larval or pupal stage. Pupae were more resistant to EPN infections than larvae. Adult emergence from inoculated pupae in soil microcosms was significantly lower than that observed in filter paper assays. Longest or largest steinernematids suppressed emergence of more adult Caribfly from pupae in soils, whereas shorter heterorhabditids were more infectious to Caribfly larvae. The highest mortalities of A. suspensa were caused by exotic nematodes Steinernema feltiae and Heterorhabditis bacteriophora, followed by the native Heterorhabditis indica and the exotic Steinernema carpocapsae. Entomopathogenic nematodes reduced the development of Caribfly larvae and pupae to adult in our bioassays, suggesting that EPNs have potential for biological control of A. suspensa. Future work will assess management strategies, using the virulent EPNs, in orchards infested by A. suspensa. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Potential of intercropping for management of some arthropod and nematode pests of leafy vegetables in Kenya

    Directory of Open Access Journals (Sweden)

    Linguya Kimaru S.

    2015-01-01

    Full Text Available African leafy vegetables (ALVs play an important role as income and food security crops in many households in Kenya. However, their potential in alleviating poverty and ensuring household food and nutrition security has not been fully exploited. The objectives of this study were to identify some arthropod and nematode pests that infest ALVs and to evaluate the effectiveness of intercropping of susceptible and resistant plants for the management purposes. Three vegetable types: African nightshade, sunn hemp and spider plant were used in determining the efficacy of an intercrop of susceptible and non-susceptible types in reducing arthropod and nematode pest effect. The treatments in the field experiment consisted of different intercrop designs and a sole crop design as control while data was taken based on five different variables. Crops in the field were infested with arthropod pests and eight different species were enumerated. The same row and hill intercropping designs were the most effective in reducing the effect of arthropod and nematode pests compared to the control plots. Spider plant and African nightshade intercrops recorded the least arthropod pest damage, higher fresh and dry shoot yields and differed significantly (P≤0.05 to African nightshade planted as a sole crop. A similar trend was observed when the experiment was repeated with a sunn hemp and African nightshade intercrop. It is concluded from this study that intercropping of different crops can be integrated with other methods to provide an easily adaptable technology to apply for effective management of arthropod and nematode pests with low external inputs.

  15. Utilizing management zones for Rotylenchulus reniformis in cotton: Effects on nematode levels, crop damage, and Pasteuria sp

    Science.gov (United States)

    Nematode management zones (MZs) based on soil electrical conductivity (EC, a proxy for soil texture) have not been published for R. reniformis. We tested 1) whether R. reniformis levels and the amount of damage caused to cotton differed among MZs, 2) if the relative effectiveness of nematicides dif...

  16. Use of spirotetramat in the post-plant management of root-knot nematode in eggplant and peach

    Science.gov (United States)

    Historically peach production and IPM management of nematodes has relied almost solely on pre- and post-plant applications of nematicides in the southeastern United States. Currently Telone II is the primary preplant fumigant used by peach growers, since methyl bromide and fenamiphos, the only post...

  17. Brassicacea-based management strategies as an alternative to combat nematode pests

    NARCIS (Netherlands)

    Fourie, Hendrika; Ahuja, Preeti; Lammers, Judith; Daneel, Mieke

    2016-01-01

    Nematode pests parasitise and cause substantial crop yield and quality losses to a wide range of crops worldwide. To minimize such damage, the exploitation and development of alternative nematode control strategies are becoming increasingly important, particularly as a result of global efforts to

  18. Nematicides and nonconventional soil amendments in the management of root-knot nematode on cotton.

    Science.gov (United States)

    Jorgenson, E C

    1984-04-01

    Granular and liquid commercial humates, with micronutrients, and a microbial fermentation product were compared in several combinations with nematicides for their effects on cotton lint yield and root-knot nematode suppression. Fumigant nematicides effectively reduced cotton root galling caused by root-knot nematodes, and cotton lint yields increased. Organophosphates and carbamates were not effective. Occasionally, cotton lint yields were increased or maintained with combination treatments o f humates, micronutrients, and a microbial fermentation product, but galling o f cotton roots by root-knot nematodes was usually not reduced by these treatments.

  19. Grafting and Paladin Pic-21 for Nematode and Weed Management in Vegetable Production

    Science.gov (United States)

    Kokalis-Burelle, Nancy; Butler, David M.; Hong, Jason C.; Bausher, Michael G.; McCollum, Greg; Rosskopf, Erin N.

    2016-01-01

    in soil and roots did not differ among soil treatments or watermelon rootstocks, and yield was lower in both grafted rootstocks compared with the nongrafted control. All soil treatments increased average fruit weight of watermelon compared with the herbicide control, and provided effective weed control, keeping the most predominant weed, purple nutsedge (Cyperus rotundus L.), density at or below 1/m row. Grafting commercial scions onto M. incognita-resistant rootstocks has potential for nematode management combined with soil treatments or as a stand-alone component in crop production systems. PMID:28154429

  20. Grafting and Paladin Pic-21 for Nematode and Weed Management in Vegetable Production.

    Science.gov (United States)

    Kokalis-Burelle, Nancy; Butler, David M; Hong, Jason C; Bausher, Michael G; McCollum, Greg; Rosskopf, Erin N

    2016-12-01

    watermelon rootstocks, and yield was lower in both grafted rootstocks compared with the nongrafted control. All soil treatments increased average fruit weight of watermelon compared with the herbicide control, and provided effective weed control, keeping the most predominant weed, purple nutsedge (Cyperus rotundus L.), density at or below 1/m row. Grafting commercial scions onto M. incognita-resistant rootstocks has potential for nematode management combined with soil treatments or as a stand-alone component in crop production systems.

  1. Efficacy of organic matter and some bio-inoculants for the management of root-knot nematode infesting tomato

    Directory of Open Access Journals (Sweden)

    Neha Khan

    2015-06-01

    Full Text Available Efficiency of an organic matter like Tagetes erecta and bioinoculants Azotobacter chroococcum and Glomus fasciculatum was investigated in tomato cultivar ‘Pusa Ruby’ when inoculated individually as well as concomitantly for the management of the root-knot nematode, Meloidogyne incognita in terms of growth parameters such as plant length, fresh and dry weights, chlorophyll content, per cent pollen fertility and mycorrhization. Greatest reduction in the numbers of second-stage juveniles in soil, number of root-galls, egg-masses and nematode multiplication was recorded with combined application of T. erecta and bio-inoculants A. chroococcum and G. fasciculatum as compared to untreated control and other treatments. Similarly, the greatest improvement in the plant growth and biomass of tomato was noted in the same treatments. However, individual inoculation of these bio-inoculants and organic fertilizers also showed significant enhancement but was less as compared to combined treatment. A. chroococcum was found most effective against disease incidence followed by G. fasciculatum and T. erecta. Parameters like NP and K contents were significantly enhanced in those plants which received combined treatments of organic matter and bio-inoculants. Azotobacter was found more efficacious against nematodes than Glomus fasciculatum. Organic matter also influenced the activity of bio-inoculants, more with the Azotobacter than G. fasciculatum. DOI: http://dx.doi.org/10.3126/ije.v4i2.12643 International Journal of Environment Vol.4(2 2015: 206-220

  2. Economic modelling of grazing management against gastrointestinal nematodes in dairy cattle.

    Science.gov (United States)

    van der Voort, M; Van Meensel, J; Lauwers, L; de Haan, M H A; Evers, A G; Van Huylenbroeck, G; Charlier, J

    2017-03-15

    Grazing management (GM) interventions, such as reducing the grazing time or mowing pasture before grazing, have been proposed to limit the exposure to gastrointestinal (GI) nematode infections in grazed livestock. However, the farm-level economic effects of these interventions have not yet been assessed. In this paper, the economic effects of three GM interventions in adult dairy cattle were modelled for a set of Flemish farms: later turnout on pasture (GM1), earlier housing near the end of the grazing season (GM2), and reducing the daily grazing time (GM3). Farm accountancy data were linked to Ostertagia ostertagi bulk tank milk ELISA results and GM data for 137 farms. The economic effects of the GM interventions were investigated through a combination of efficiency analysis and a whole-farm simulation model. Modelling of GM1, GM2 and GM3 resulted in a marginal economic effect of € 8.36, € -9.05 and € -53.37 per cow per year, respectively. The results suggest that the dairy farms can improve their economic performance by postponing the turnout date, but that advancing the housing date or reducing daily grazing time mostly leads to a lower net economic farm performance. Overall, the GM interventions resulted in a higher technical efficiency and milk production but these benefits were offset by increased feed costs as a result of higher maintenance and cultivation costs. Because the results differed highly between farms, GM interventions need to be evaluated at the individual level for appropriate decision support. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Management of Plant-parasitic Nematodes on Peanut with Selected Nematicides in North Carolina.

    Science.gov (United States)

    Koenning, S R; Bailey, J E; Schmitt, D P; Barker, K R

    1998-12-01

    Field experiments were conducted to determine peanut growth and yield responses to selected fumigant and nonfumigant nemaficide treatments in 1988 and 1989. All treatments with the fumigant 1, 3-D significantly suppressed nematode reproduction (Meloidogyne arenaria, M. hapla, and Mesocriconema ornatum) and enhanced peanut yields over the other treatments in four tests in 1988. Yield increases with the fumigant ranged from about 20% to 100% over the untreated control. Test sites in 1989 had lower nematode levels than those for 1988, and fewer positive plant and nematode responses were detected. Treatments with 1,3-D improved peanut quality but not yield in one experiment with low levels of M. hapla and M. ornatum in 1988. The 1,3-D + chloropicrin treatments at another site gave higher peanut yields than 1,3-D alone.

  4. Epidemiology of gastrointestinal nematodes of sheep managed under traditional husbandry system in Kashmir valley.

    Science.gov (United States)

    Tariq, K A; Chishti, M Z; Ahmad, F; Shawl, A S

    2008-11-25

    The present study was conducted with the objective to investigate the seasonal epidemiological prevalence of gastrointestinal tract (GIT) nematodes in different age groups, sexes and breeds (genotypes) of sheep through necropsy and faecal analysis over a period of 2 years in Kashmir valley, India. A total of 1533 sheep were examined [faecal examination: 1035 (year 1: 561, year 2: 474); necropsy: 498 (year 1: 232, year 2: 266)]. Out of these, 945 (61.64%) were found infected [faecal examination: 697 (67.34%, year 1: 390 (69.51%), year 2: 307 (46.99%); necropsy: 248 (49.79%, year 1: 123 (53.01%), year 2: 125 (64.69%)] with GIT nematodes. The over all prevalence of GIT nematodes in sheep in year 1 was 64.76 and 58.37% in year 2 (P=0.04). The parasites in decreasing order of prevalence (%) in sheep were Haemonchus contortus (59.6); Ostertagia circumcincta (38.0); Bunostomum trigonocephalum (37.7); Chabertia ovina (37.7); Trichostrongylus spp. (33.9); Nematodirus spathiger (29.4); Oesophagostomum columbianum (28.4); Trichuris ovis (23.5) and Marshallagia marshalli (22.1). Season, sex, age, and genotype were the factors that influenced the epidemiological prevalence of GIT nematodes in sheep in the present study. The maximum nematode infection was observed in summer season and lowest in winter (P=0.0005). Local Kashmiri breed was less infected as compared to other genotypes (P>0.05). Lower age groups were more infected than adult animals (P>/=0.05). Prevalence was higher in rams (males) than eves (females) (P>0.05). The present study will initially be of great significance to add to the existing knowledge of the epidemiology of GIT nematodes of small ruminants and the findings will be quite helpful to devise the appropriate control and prophylactic strategies for GIT nematodiasis of sheep reared under the temperate agro-climatic conditions.

  5. Resistant Citrullus lanatus var. citroides Rootstocks for Managing Root-knot Nematodes in Grafted Watermelon

    Science.gov (United States)

    Southern root-knot nematode (RKN), Meloidogyne incognita, is an important re-emerging pest of watermelon. Several factors have contributed to re-emergence of RKN including: 1) ban of methyl bromide for soil fumigation; 2) reduced land area for crop rotation; and 3) continuous cropping of cucurbits u...

  6. Quantitative studies on the management of potato cyst nematodes (Globodera spp.) in the Netherlands.

    NARCIS (Netherlands)

    Been, T.H.; Schomakers, C.H.

    1998-01-01

    Potatoes are among the most profitable agricultural crops in arable farming in the Netherlands and consequently are grown as frequently as conditions allow. As a result Dutch farmers experienced huge problems with potato cyst nematodes during the last 50 years. In Chapter 1 an outli

  7. Impact of rotational grazing on management of gastrointestinal nematodes in weaned lambs

    Science.gov (United States)

    Gastrointestinal nematode (GIN) control for ‘natural’ or organic lamb production is needed, especially where Haemonchus contortus is prevalent. The objective was to determine the impact of rotational grazing on GIN infection of weaned lambs. In year 1, naturally infected Katahdin lambs (120 days of ...

  8. Quantitative studies on the management of potato cyst nematodes (Globodera spp) in The Netherlands

    NARCIS (Netherlands)

    Been, T.H.; Schomaker, C.H.

    1998-01-01

    Potatoes are among the most profitable agricultural crops in arable farming in the Netherlands and consequently are grown as frequently as conditions allow. As a result Dutch farmers experienced huge problems with potato cyst nematodes during the last 50 years. In Chapter 1<

  9. Managing root-knot nematodes: A case for cover crops in establishing peach orchards

    Science.gov (United States)

    Root-knot nematodes (Meloidogyne spp.) are an important pathogen of peach in the United States. Several Meloidogyne spp. have been reported to cause damage to stone fruits, but M. incognita and M. javanica are the predominant species on peach. Preplant fumigant nematicides have traditionally been ...

  10. Impact of integrated gastrointestinal nematode management training for U.S. goat and sheep producers.

    Science.gov (United States)

    Whitley, N C; Oh, S-H; Lee, S J; Schoenian, S; Kaplan, R M; Storey, B; Terrill, T H; Mobini, S; Burke, J M; Miller, J E; Perdue, M A

    2014-03-01

    The objective of this study was to determine the impact of integrated parasite management (IPM) training, including FAMACHA(©) eyelid color scoring, on the ability of U.S. sheep and goat producers to control gastrointestinal nematodes (GIN) on their farms. A survey was developed and provided to over 2000 producers trained from 2004 to 2008 in IPM with questions involving farm size (number of sheep/goats), location (U.S. state), impact of training on parasite control efforts and parasite problems on farm, and IPM practices used. Responses were divided into U.S. Census regions of the U.S. Descriptive statistics and logistic regression were used to describe results. Most of the 729 respondents were from the southern region of the U.S. (54.3%) and were small-scale producers (50 or less animals; 64.8%). Nearly all of the respondents (95.1%) agreed that IPM workshop attendance made a difference in their ability to control and monitor parasitism in their herd or flock and employed IPM practices to control GIN (96.3%). The most popular practices respondents used were rotational grazing (71.2%), genetic selection (choosing a parasite resistant breed and/or culling susceptible animals; 52.7%), grain supplementation on pasture to improve nutrition (44.0%), and increased height of plants being grazed (41.8%). Although reporting using a practice decreased (P<0.05) the likelihood of reporting fewer problems, for each 1-point increase in the number of practices which producers employed to control internal parasitism in their herd or flock, they were 16% more likely to report fewer GIN problems (P<0.05). Approximately 75% of respondents indicated an economic benefit of IPM on their farm (P<0.05), and those reporting savings of over $80 were more likely to report fewer problems (P<0.05) with parasites after the training while those reporting no economic benefit were less likely to report fewer problems with GIN (P<0.001). Overall, IPM training resulted in positive impacts for

  11. Root-knot Nematode Management and Yield of Soybean as Affected by Winter Cover Crops, Tillage Systems, and Nematicides.

    Science.gov (United States)

    Minton, N A; Parker, M B

    1987-01-01

    Management of Meloidogyne incognita on soybean as affected by winter small grain crops or fallow, two tillage systems, and nematicides was studied. Numbers of M. incognita did not differ in plots planted to wheat and rye. Yields of soybean planted after these crops also did not differ. Numbers of M. incognita were greater in fallow than in rye plots, but soybean yield was not affected by the two treatments. Soybean yields were greater in subsoil-plant than in moldboard plowed plots. Ethylene dibromide reduced nematode population densities more consistently than aldicarb and phenamiphos. Also, ethylene dibromide increased yields the most and phenamiphos the least. There was a positive correlation (P = 0.001) of seed size (weight of 100 seeds) with yield (r = 0.79), indicating that factors affecting yield also affected seed size.

  12. Fascinating metabolic pools of Pelargonium sidoides and Pelargonium reniforme, traditional and phytomedicinal sources of the herbal medicine Umckaloabo.

    Science.gov (United States)

    Kolodziej, Herbert

    2007-01-01

    The metabolic pools of Pelargonium sidoides DC and Pelargonium reniforme CURT, associated with the origin of the herbal medicine Umckaloabo, exhibit remarkable diversity and complexity. They comprise a variety of phenolic and polyphenolic compounds, a notable wealth of highly oxygenated simple coumarins and a number of miscellaneous uncommon metabolites. Noteworthy, the roots of both species express conspicuously distinct coumarin variations that facilitate their identification. Of the range of coumarins identified the titled species shared the ubiquitous scopoletin and the unique members 6,7,8-trihydroxycoumarin and 8-hydroxy-5,6,7-trimethoxycoumarin merely. Furthermore, the current data on the coumarin profiles suggest the occurrence of coumarin sulphates and coumarin glycosides to be apparently confined to P. sidoides, while the occurrence of conventional proanthocyanidins was a common chemical feature. An unprecedented diterpene, designated as reniformin, was encountered in the roots of P. reniforme, possessing a novel diterpene skeleton linked to a unique p-oxyphenethansulfonic moiety. Coumarins were less abundant in the aerial parts of both species. These were rich in flavonoids and hydrolysable tannins including a unique series of O-galloyl-C-glucosylflavones (P. sidoides and P. reniforme) and novel ellagitannins with a (1)C(4) glucopyranose core in P. reniforme, trivially named pelargoniins, accompanied by the new 4-allyl-2,5-dimethoxyphenol-1-beta-D-glucoside. These Pelargoniums have thus represented an attractive source of fascinating secondary metabolites. A proprietary extract of the roots of P. sidoides, EPs 7630, has been developed from this traditional herbal medicine and introduced into modern phytotherapy in Europe. Structural examination of EPs 7630 constituents showed excellent agreement of the profile with that of P. sidoides.

  13. Conjoint effect of oil-seed cakes and Pseudomonas fluorescens on the growth of chickpea in relation to the management of plant-parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Rose Rizvi

    2012-12-01

    Full Text Available Soil application of organics has been explored as an alternative means of organic management of plant-parasitic nematodes. Efficiency of different oil-seed cakes of neem (Azadirachta indica, castor (Ricinus communis, groundnut (Arachis hypogaea, linseed (Linum usitatissimum, sunflower (Helianthus annuus and soybean (Glycine max were evaluated in field conditions with association of Pseudomonas fluorescens in relation to growth parameters of chickpea and population of plant-parasitic nematodes. Their efficacious nature was highly effective in reducing the population of these dominant soil nematodes. Significant improvement was observed in plant-growth parameters such as plant weight, percent pollen fertility, pod numbers, root-nodulation and chlorophyll content of chickpea, seemed to be due to reduction in disease incidence and might be due to growth promoting substances secreted by P. fluorescens. The multiplication rate of nematodes was less in the presence of P. fluorescens as compared to its absence. Most effective combination of P. fluorescens was observed with neem cake.

  14. Manejo integrado de nematóides na cultura da bananeira Integrated management of nematodes in the banana tree culture

    Directory of Open Access Journals (Sweden)

    Cecília Helena Silvino Prata Ritzinger

    2006-08-01

    Full Text Available O manejo integrado é uma exigência dos mercados importadores, sobretudo da Comunidade Européia (CE, rigorosa em requisitos de qualidade e sustentabilidade, que enfatiza primordialmente a proteção do meio ambiente, segurança alimentar, condições de trabalho, saúde humana e viabilidade econômica. Neste contexto, a utilização da matéria orgânica no manejo dos solos é uma das estratégias que mais benefícios traz à biodiversidade e conservação dos solos. É prática conhecida desde os primórdios da civilização. Contudo, sua utilização de forma efetiva depende ainda do conhecimento de muitas interações que ocorrem no agroecossistema. São apresentados alguns estudos de sua utilização no manejo integrado de fitonematóides e perspectivas de validação, com enfoque na cultura da bananeira e possibilidades de sua adoção para atender à demanda de sustentabilidade.The integrated management is a requirement of the European Community (CE which demands rigorous quality product and sustainability, which is emphasized primarily on the environment protection, food safety, work conditions, human health and economical viability. In this context, the use of organic amendments for soil management is one of the strategies that brings the most benefits to soil biodiversity and conservation. This practice is known since the beginning of the civilization. Nevertheless, an effective use still depends on the knowledge of the many interactions in the agro-ecosystem. This review presents some studies of its use in integrated management of plant parasitic nematodes, validation perspectives focused in banana and use possibilities to assist the sustainability demand.

  15. Efficacy of Various Application Methods of Fluensulfone for Managing Root-knot Nematodes in Vegetables

    Science.gov (United States)

    Morris, Kelly A.; Langston, David B.; Davis, Richard F.; Noe, James P.; Dickson, Don W.; Timper, Patricia

    2016-01-01

    Fluensulfone is a new nematicide in the flouroalkenyl chemical group. A field experiment was conducted in 2012 and 2013 to evaluate the efficacy of various application methods of fluensulfone for control of Meloidogyne spp. in cucumber (Cucumis sativus). Treatments of fluensulfone (3.0 kg a.i./ha) were applied either as preplant incorporation (PPI) or via different drip irrigation methods: drip without pulse irrigation (Drip NP), pulse irrigation 1 hr after treatment (Drip +1P), and treatment at the same time as pulse irrigation (Drip =P). The experiment had eight replications per treatment and also included a PPI treatment of oxamyl (22.5 kg a.i./ha) and a nontreated control. Compared to the control, neither the oxamyl nor the fluensulfone PPI treatments reduced root galling by Meloidogyne spp. in cucumber. Among the drip treatments, Drip NP and Drip +1P reduced root galling compared to the control. Cucumber yield was greater in all fluensulfone treatments than in the control. In a growth-chamber experiment, the systemic activity and phytotoxicity of fluensulfone were also evaluated on tomato (Solanum lycopersicum), eggplant (Solanum melongena), cucumber, and squash (Curcurbita pepo). At the seedling stage, foliage of each crop was sprayed with fluensulfone at 3, 6, and 12 g a.i./liter, oxamyl at 4.8 g a.i./liter, or water (nontreated control). Each plant was inoculated with Meloidogyne incognita juveniles 2 d after treatment. There were six replications per treatment and the experiment was conducted twice. Foliar applications of fluensulfone reduced plant vigor and dry weight of eggplant and tomato, but not cucumber or squash; application of oxamyl had no effect on the vigor or weight of any of the crops. Typically, only the highest rate of fluensulfone was phytotoxic to eggplant and tomato. Tomato was the only crop tested in which there was a reduction in the number of nematodes or galls when fluensulfone or oxamyl was applied to the foliage compared to the

  16. Root-knot nematodes

    NARCIS (Netherlands)

    Karssen, G.; Wesemael, W.M.L.; Moens, M.

    2013-01-01

    Plant-parasitic nematodes devastate crops worldwide, in turn impacting international trade, social and economic development. Effective control of nematodes is essential for crop protection, and requires an understanding of nematode biology, taxonomy, population dynamics and sampling methods.

  17. Root-knot nematodes

    NARCIS (Netherlands)

    Karssen, G.; Wesemael, W.M.L.; Moens, M.

    2013-01-01

    Plant-parasitic nematodes devastate crops worldwide, in turn impacting international trade, social and economic development. Effective control of nematodes is essential for crop protection, and requires an understanding of nematode biology, taxonomy, population dynamics and sampling methods. Providi

  18. Nematode neuropeptides as transgenic nematicides.

    Science.gov (United States)

    Warnock, Neil D; Wilson, Leonie; Patten, Cheryl; Fleming, Colin C; Maule, Aaron G; Dalzell, Johnathan J

    2017-02-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars.

  19. Influence of management and biological factors on parasitic invasions in the wild – Spread of the blood-sucking nematode Ashworthius sidemi in European bison (Bison bonasus

    Directory of Open Access Journals (Sweden)

    Marta Kołodziej-Sobocińska

    2016-12-01

    Full Text Available The full course of new parasite introductions in wild animals is difficult to accurately trace. We documented and analysed the invasive blood-sucking nematode Ashworthius sidemi (Trichostrongylidae introduction and spread in European bison (Bison bonasus from the initial phase of its progression. In the Polish part of the Białowieża Primeval Forest (BPF the parasite was first found in 2000. From 2002 to 2015, 165 culled bison were investigated. The prevalence and intensity of A. sidemi Schulz, 1933 infection increased over the following years, reaching 100% of investigated bison four years after introduction and a maximal median intensity of 8200 nematodes per animal in the winter of 2008/2009. Afterwards, a significant decline of median infection intensity was observed to the minimum value of 410 nematodes per animal. Between 2011 and 2014 prevalence varied from 89 to 100%. Among the factors analysed, the number of years since introduction, herd size, age and sex proved to significantly influence infection intensity. A higher infection intensity was recorded in sub-adults compared to juveniles and adults. Males had significantly lower infection intensity than females, but this was the case for adults only. The highest infection intensities were recorded in the biggest bison herds, where the winter supplementary feeding of bison is intense. Moreover, the longer the parasite was present in the host population, the more important herd size became as a factor. Our study indicates that it is not solely biological factors that determine the spread of a newly detected parasite in wildlife, but that management practices can also have a strong influence. This is especially important in endangered species under intensive human care as the management practices may pose a threat to the species.

  20. Soybean cyst nematode culture collections and field populations from North Carolina and Missouri reveal high incidences of infection by viruses.

    Science.gov (United States)

    Ruark, Casey L; Koenning, Stephen R; Davis, Eric L; Opperman, Charles H; Lommel, Steven A; Mitchum, Melissa G; Sit, Tim L

    2017-01-01

    Five viruses were previously discovered infecting soybean cyst nematodes (SCN; Heterodera glycines) from greenhouse cultures maintained in Illinois. In this study, the five viruses [ScNV, ScPV, ScRV, ScTV, and SbCNV-5] were detected within SCN greenhouse and field populations from North Carolina (NC) and Missouri (MO). The prevalence and titers of viruses in SCN from 43 greenhouse cultures and 25 field populations were analyzed using qRT-PCR. Viral titers within SCN greenhouse cultures were similar throughout juvenile development, and the presence of viral anti-genomic RNAs within egg, second-stage juvenile (J2), and pooled J3 and J4 stages suggests active viral replication within the nematode. Viruses were found at similar or lower levels within field populations of SCN compared with greenhouse cultures of North Carolina populations. Five greenhouse cultures harbored all five known viruses whereas in most populations a mixture of fewer viruses was detected. In contrast, three greenhouse cultures of similar descent to one another did not possess any detectable viruses and primarily differed in location of the cultures (NC versus MO). Several of these SCN viruses were also detected in Heterodera trifolii (clover cyst) and Heterodera schachtii (beet cyst), but not the other cyst, root-knot, or reniform nematode species tested. Viruses were not detected within soybean host plant tissue. If nematode infection with viruses is truly more common than first considered, the potential influence on nematode biology, pathogenicity, ecology, and control warrants continued investigation.

  1. An ellagitannin, n-butyl gallate, two aryltetralin lignans, and an unprecedented diterpene ester from Pelargonium reniforme.

    Science.gov (United States)

    Latté, Klaus Peter; Kaloga, Maki; Schäfer, Andreas; Kolodziej, Herbert

    2008-02-01

    The structural diversity of the metabolic pool of Pelargonium reniforme was extended by the characterization of the 1C4-glucose based ellagitannin pelargoniin E, gallic acid n-butyl ester, (-)-4,4',9'-trihydroxy-3',5'-dimethoxy-2,7'-cyclolignan 9-O-beta-glucopyranoside and reniformin, a diterpene ester comprised of a diterpene acid with an uncommon -(CH2)(2)- bridging element linked to 2-(4-hydroxyphenyl)ethansulfonic acid. These metabolites were associated with the known (alpha,beta)-3,4-di-O-galloyl-glucopyranoside, 4,6-dihydroxy-2beta-glucopyranosyloxyacetophenone, 1-O-galloylglycerol, 6'-O-galloylsalidroside and (+)-isolariciresinol-9'-O-beta-glucopyranoside. All structures were established on the basis of spectroscopic methods.

  2. Proof of concept of faecal egg nematode counting as a practical means of veterinary engagement with planned livestock health management in a lower income country.

    Science.gov (United States)

    Leahy, Eithne; Bronsvoort, Barend; Gamble, Luke; Gibson, Andrew; Kaponda, Henderson; Mayer, Dagmar; Mazeri, Stella; Shervell, Kate; Sargison, Neil

    2017-01-01

    The wellbeing and livelihood of farmers in impoverished regions of the world is intrinsically linked to the health and welfare of their livestock; hence improved animal health is a pragmatic component of poverty alleviation. Prerequisite knowledge and understanding of the animal health challenges facing cattle keepers in Malawi is constrained by the lack of veterinary infrastructure, which inevitably accompanies under-resourced rural development in a poor country. We collaborated with public and private paraveterinary services to locate 62 village Zebu calves and 60 dairy co-operative calves dispersed over a wide geographical area. All calves were visited twice about 2 to 3 weeks apart, when they were clinically examined and faecal samples were collected. The calves were treated with 7.5 mg/kg of a locally-available albendazole drench on the first visit, and pre- and post- treatment trichostrongyle and Toxocara faecal egg counts were performed using a modified McMaster method. Our clinical findings point towards a generally poor level of animal health, implying a role of ticks and tick-transmitted diseases in village calves and need for improvement in neonatal calf husbandry in the dairy co-operative holdings. High faecal trichostrongyle egg counts were not intuitive, based on our interpretation of the animal management information that was provided. This shows the need for better understanding of nematode parasite epidemiology within the context of local husbandry and environmental conditions. The albendazole anthelmintic was effective against Toxocara, while efficacy against trichostrongyle nematodes was poor in both village and dairy co-operative calves, demonstrating the need for further research to inform sustainable drug use. Here we describe the potential value of faecal nematode egg counting as a platform for communicating with and gaining access to cattle keepers and their animals, respectively, in southern Malawi, with the aim of providing informative

  3. Nematode diversity in agroecosystems

    NARCIS (Netherlands)

    Yeates, G.W.; Bongers, T.

    1999-01-01

    The diversity of nematode faunae in agroecosystems and their relationships to soil processes suggests that they are potential bioindicators. However, the effects of plants, soil types and nematode biogeography mean a 'functional group' may be a better indicator than particular nematodes.

  4. Parasitic nematodes - from genomes to control.

    Science.gov (United States)

    Mitreva, Makedonka; Zarlenga, Dante S; McCarter, James P; Jasmer, Douglas P

    2007-08-19

    The diseases caused by parasitic nematodes in domestic and companion animals are major factors that decrease production and quality of the agricultural products. Methods available for the control of the parasitic nematode infections are mainly based on chemical treatment, non-chemical management practices, immune modulation and biological control. However, even with integrated pest management that frequently combines these approaches, the effective and long-lasting control strategies are hampered by the persistent exposure of host animals to environmental stages of parasites, the incomplete protective response of the host and acquisition of anthelmintic resistance by an increasing number of parasitic nematodes. Therefore, the challenges to improve control of parasitic nematode infections are multi-fold and no single category of information will meet them all. However, new information, such as nematode genomics, functional genomics and proteomics, can strengthen basic and applied biological research aimed to develop improvements. In this review we will, summarize existing control strategies of nematode infections and discuss ongoing developments in nematode genomics. Genomics approaches offer a growing and fundamental base of information, which when coupled with downstream functional genomics and proteomics can accelerate progress towards developing more efficient and sustainable control programs.

  5. Anthelmintic resistance in equine nematodes

    Science.gov (United States)

    Matthews, Jacqueline B.

    2014-01-01

    Anthelmintics have been applied indiscriminately to control horse nematodes for over 40 years. Three broad-spectrum anthelmintic classes are currently registered for nematode control in horses: benzimidazoles (fenbendazole, oxibendazole), tetrahydropyrimidines (pyrantel) and macrocyclic lactones (ivermectin, moxidectin). Generally, control strategies have focused on nematode egg suppression regimens that involve the frequent application of anthelmintics to all horses at intervals based on strongyle egg reappearance periods after treatment. The widespread use of such programmes has substantially reduced clinical disease, especially that associated with large strongyle species; however, high treatment frequency has led to considerable selection pressure for anthelmintic resistance, particularly in cyathostomin species. Field studies published over the last decade indicate that benzimidazole resistance is widespread globally in cyathostomins and there are also many reports of resistance to pyrantel in these worms. Cyathostomin resistance to macrocyclic lactone compounds is emerging, principally measured as a reduction in strongyle egg reappearance time observed after treatment. Ivermectin resistance is a further concern in the small intestinal nematode, Parascaris equorum, an important pathogen of foals. These issues indicate that horse nematodes must now be controlled using methods less dependent on anthelmintic use and more reliant on management practices designed to reduce the force of infection in the environment. Such strategies include improved grazing management integrated with targeted anthelmintic administration involving faecal egg count (FEC)-directed treatments. The latter require that the supporting diagnostic tests available are robust and practically applicable. Recent research has focused on maximising the value of FEC analysis in horses and on optimizing protocols for anthelmintic efficacy testing. Other studies have sought to develop diagnostics

  6. Anthelmintic resistance in equine nematodes

    Directory of Open Access Journals (Sweden)

    Jacqueline B. Matthews

    2014-12-01

    Full Text Available Anthelmintics have been applied indiscriminately to control horse nematodes for over 40 years. Three broad-spectrum anthelmintic classes are currently registered for nematode control in horses: benzimidazoles (fenbendazole, oxibendazole, tetrahydropyrimidines (pyrantel and macrocyclic lactones (ivermectin, moxidectin. Generally, control strategies have focused on nematode egg suppression regimens that involve the frequent application of anthelmintics to all horses at intervals based on strongyle egg reappearance periods after treatment. The widespread use of such programmes has substantially reduced clinical disease, especially that associated with large strongyle species; however, high treatment frequency has led to considerable selection pressure for anthelmintic resistance, particularly in cyathostomin species. Field studies published over the last decade indicate that benzimidazole resistance is widespread globally in cyathostomins and there are also many reports of resistance to pyrantel in these worms. Cyathostomin resistance to macrocyclic lactone compounds is emerging, principally measured as a reduction in strongyle egg reappearance time observed after treatment. Ivermectin resistance is a further concern in the small intestinal nematode, Parascaris equorum, an important pathogen of foals. These issues indicate that horse nematodes must now be controlled using methods less dependent on anthelmintic use and more reliant on management practices designed to reduce the force of infection in the environment. Such strategies include improved grazing management integrated with targeted anthelmintic administration involving faecal egg count (FEC-directed treatments. The latter require that the supporting diagnostic tests available are robust and practically applicable. Recent research has focused on maximising the value of FEC analysis in horses and on optimizing protocols for anthelmintic efficacy testing. Other studies have sought to develop

  7. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants.

    Science.gov (United States)

    Silvestre, A; Cabaret, J

    2004-06-01

    In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control)? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation) are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole). Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy) are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial: it is not possible to avoid it, but only to delay its development in farm animal industry.

  8. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

    Directory of Open Access Journals (Sweden)

    Silvestre A.

    2004-06-01

    Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

  9. Pineapple nematode research in hawaii: past, present, and future.

    Science.gov (United States)

    Caswell, E P; Apt, W J

    1989-04-01

    The first written record of pineapple in Hawaii is from 1813. In 1901 commercial pineapple production started, and in 1924 the Experiment Station for pineapple research was established. Nematode-related problems were recognized in the early 1900s by N. A. Cobb. From 1920 to approximately 1945 nematode management in Hawaiian pineapple was based on fallowing and crop rotation. During the 1920s and 1930s G. H. Godfrey conducted research on pineapple nematode management. In the 1930s and 1940s M. B. Linford researched biological control and described several new species of nematodes including Rotylenchulus reniformis. In 1941 nematology and nematode management were advanced by Walter Carter's discovery of the first economical soil fumigant for nematodes, D-D mixture. Subsequently, DBCP was discovered and developed at the Pineapple Research Institute (PRI). Since 1945 soil fumigation has been the main nematode management strategy in Hawaiian pineapple production. Recent research has focused on the development of the nonvolatile nematicides, their potential as systemic nematicides, and their application via drip irrigation. Current and future research addresses biological and cultural alternatives to nematicide-based nematode management.

  10. Extracting DNA of nematodes communities from Argentine Pampas agricultural soils

    Directory of Open Access Journals (Sweden)

    Eduardo A. Mondino

    2015-06-01

    Full Text Available We examined four strategies (Tris/EDTA, sodium dodecyl sulfate, Chelex 100 resin and cetyltrimethylammonium bromide -CTAB- for extracting nucleic acid (DNA from communities of nematodes. Nematodes were isolated from an agricultural area under different management of long-term crop rotation experiment from Argentina during three seasons. After DNA extraction, Polymerase Chain Reaction-amplifications were performed and considered as indicators of successful DNA extraction. The CTAB combined with proteinase K and phenol-chloroform-isoamyl alcohol was the unique successful method because positive amplifications were obtained by using both eukaryotic and nematode specific primers. This work could contribute to biodiversity studies of nematodes on agroecosystems.

  11. Extracting DNA of nematodes communities from Argentine Pampas agricultural soils.

    Science.gov (United States)

    Mondino, Eduardo A; Covacevich, Fernanda; Studdert, Guillermo A; Pimentel, João P; Berbara, Ricardo L L

    2015-01-01

    We examined four strategies (Tris/EDTA, sodium dodecyl sulfate, Chelex 100 resin and cetyltrimethylammonium bromide -CTAB-) for extracting nucleic acid (DNA) from communities of nematodes. Nematodes were isolated from an agricultural area under different management of long-term crop rotation experiment from Argentina during three seasons. After DNA extraction, Polymerase Chain Reaction-amplifications were performed and considered as indicators of successful DNA extraction. The CTAB combined with proteinase K and phenol-chloroform-isoamyl alcohol was the unique successful method because positive amplifications were obtained by using both eukaryotic and nematode specific primers. This work could contribute to biodiversity studies of nematodes on agroecosystems.

  12. Entomopathogenic Nematodes Combined with Adjuvants Presents a New Potential Biological Control Method for Managing the Wheat Stem Sawfly, Cephus cinctus (Hymenoptera: Cephidae).

    Science.gov (United States)

    Portman, Scott L; Krishnankutty, Sindhu M; Reddy, Gadi V P

    2016-01-01

    The wheat stem sawfly, (Cephus cinctus Norton) Hymenoptera: Cephidae, has been a major pest of winter wheat and barley in the northern Great Plains for more than 100 years. The insect's cryptic nature and lack of safe chemical control options make the wheat stem sawfly (WSS) difficult to manage; thus, biological control offers the best hope for sustainable management of WSS. Entomopathogenic nematodes (EPNs) have been used successfully against other above-ground insect pests, and adding adjuvants to sprays containing EPNs has been shown to improve their effectiveness. We tested the hypothesis that adding chemical adjuvants to sprays containing EPNs will increase the ability of EPNs to enter wheat stems and kill diapausing WSS larvae. This is the first study to test the ability of EPNs to infect the WSS, C. cinctus, and test EPNs combined with adjuvants against C. cinctus in both the laboratory and the field. Infection assays showed that three different species of EPNs caused 60-100% mortality to WSS larvae. Adding Penterra, Silwet L-77, Sunspray 11N, or Syl-Tac to solutions containing EPNs resulted in higher WSS mortality than solutions made with water alone. Field tests showed that sprays containing S. feltiae added to 0.1% Penterra increased WSS mortality up to 29.1%. These results indicate a novel control method for WSS, and represent a significant advancement in the biological control of this persistent insect pest.

  13. Management of crotalaria and pigeon pea for control of yam nematode diseases Manejo da crotalária e do guandu no controle de nematoses do inhame

    Directory of Open Access Journals (Sweden)

    Marlon da Silva Garrido

    2008-09-01

    Full Text Available Management of plant-parasitic nematodes with the use of nematicides has not been recommended for small farmers that grow yam in the Northeastern region of Brazil, due to its high cost and residue toxicity. The use of plants with antagonistic effect to nematodes and green manure which improves soil chemical, physical and biological characteristics can be a viable and low cost alternative to control parasitic nematodes. This work aimed to evaluate the effect of crotalaria (Crotalaria juncea and pigeon pea (Cajanus cajan plants on the control of yam nematodes. Three experiments were carried out. The first was conducted under in vitro conditions to evaluate the nematostatic and nematicide effect of extracts from fresh and dry matter of the above ground parts of crotalaria, pigeon pea, and the combination of both. The second experiment was carried out under greenhouse conditions to evaluate the effect of soil amendment with crotalaria, pigeon pea, and the combination of both in the infectivity of Scutellonema bradys, using tomato plants as the host plant. The third experiment was conducted under field conditions to evaluate the effect of crotalaria, pigeon pea, and the combination of both, cultivated between yam planting rows and incorporated to soil surface, on yam nematodes. The aqueous extract obtained form fresh matter of crotalaria had a nematicide effect of 100% for S. bradys. Extracts from dry matter of both crotalaria and pigeon pea did not have any nematicide effect, but had a nematostatic effect. Incorporation of crotalaria to soil inhibited infectivity of S. bradys in tomato seedlings. These results showed that planting crotalaria alone or in combination with pigeon pea, between the yam planting rows, is an efficient method for controlling S. bradys and Rotylenchulus reniformis associated with yams. Crotalaria can be used for controlling these plant-parasitic nematodes in soil.O manejo de fitomenatóides com o uso de nematicidas não tem

  14. Nematode-Trapping Fungi.

    Science.gov (United States)

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  15. The Nematode Caenorhabditis Elegans.

    Science.gov (United States)

    Kenyon, Cynthia

    1988-01-01

    Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

  16. Insights into Adaptations to a Near-Obligate Nematode Endoparasitic Lifestyle from the Finished Genome of Drechmeria coniospora

    NARCIS (Netherlands)

    Zhang, L.; Zhou, Z.; Guo, Q.; Fokkens, L.; Miskei, M.; Pócsi, I.; Zhang, W.; Chen, M.; Wang, L.; Sun, Y.; Donzelli, B.G.G.; Gibson, D.M.; Nelson, D.R.; Luo, J.G.; Rep, M.; Liu, H.; Yang, S.; Wang, J.; Krasnoff, S.B.; Xu, Y.; Molnár, I.; Lin, M.

    2016-01-01

    Nematophagous fungi employ three distinct predatory strategies: nematode trapping, parasitism of females and eggs, and endoparasitism. While endoparasites play key roles in controlling nematode populations in nature, their application for integrated pest management is hindered by the limited

  17. Soybean cyst nematode culture collections and field populations from North Carolina and Missouri reveal high incidences of infection by viruses

    Science.gov (United States)

    Ruark, Casey L.; Koenning, Stephen R.; Davis, Eric L.; Opperman, Charles H.; Lommel, Steven A.; Mitchum, Melissa G.; Sit, Tim L.

    2017-01-01

    Five viruses were previously discovered infecting soybean cyst nematodes (SCN; Heterodera glycines) from greenhouse cultures maintained in Illinois. In this study, the five viruses [ScNV, ScPV, ScRV, ScTV, and SbCNV-5] were detected within SCN greenhouse and field populations from North Carolina (NC) and Missouri (MO). The prevalence and titers of viruses in SCN from 43 greenhouse cultures and 25 field populations were analyzed using qRT-PCR. Viral titers within SCN greenhouse cultures were similar throughout juvenile development, and the presence of viral anti-genomic RNAs within egg, second-stage juvenile (J2), and pooled J3 and J4 stages suggests active viral replication within the nematode. Viruses were found at similar or lower levels within field populations of SCN compared with greenhouse cultures of North Carolina populations. Five greenhouse cultures harbored all five known viruses whereas in most populations a mixture of fewer viruses was detected. In contrast, three greenhouse cultures of similar descent to one another did not possess any detectable viruses and primarily differed in location of the cultures (NC versus MO). Several of these SCN viruses were also detected in Heterodera trifolii (clover cyst) and Heterodera schachtii (beet cyst), but not the other cyst, root-knot, or reniform nematode species tested. Viruses were not detected within soybean host plant tissue. If nematode infection with viruses is truly more common than first considered, the potential influence on nematode biology, pathogenicity, ecology, and control warrants continued investigation. PMID:28141854

  18. Toward 959 nematode genomes

    National Research Council Canada - National Science Library

    Kumar, Sujai; Koutsovoulos, Georgios; Kaur, Gaganjot; Blaxter, Mark

    2012-01-01

    The sequencing of the complete genome of the nematode Caenorhabditis elegans was a landmark achievement and ushered in a new era of whole-organism, systems analyses of the biology of this powerful model organism...

  19. Advance of entomopathogenic nematodes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper summarized the history and present condition of studying and utilizing entomopathogenic nematodes at home and abroad, expounded its taxonomy, life cycle and the mechanism with symbiotic bacteria killing host insect. Taxonomy, mycelial form, pathogenic function and anti-bacteria function of symbiotic bacteria were introduced. Production and utilization of entomopathogenic nematodes, the characteristic genetic improvement by use of biological engineering technology, as well as the existing problem and applying foreground were also discussed.

  20. Growing Tomato (Lycopersicon esculentum L.) in Nematode ...

    African Journals Online (AJOL)

    Infested Soil and the Pest Implications in Poorly Managed. Post-harvested Fields ... In this study, the effect of Procarvian carpensis manure at a rate of 5tons/ha and the balanced ... nematode in Tabora environmental condition. Furthermore ...

  1. Transgenic Strategies for Enhancement of Nematode Resistance in Plants

    Directory of Open Access Journals (Sweden)

    Muhammad A. Ali

    2017-05-01

    Full Text Available Plant parasitic nematodes (PPNs are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants.

  2. Transgenic Strategies for Enhancement of Nematode Resistance in Plants.

    Science.gov (United States)

    Ali, Muhammad A; Azeem, Farrukh; Abbas, Amjad; Joyia, Faiz A; Li, Hongjie; Dababat, Abdelfattah A

    2017-01-01

    Plant parasitic nematodes (PPNs) are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants.

  3. Characterization of the two intra-individual sequence variants in the 18S rRNA gene in the plant parasitic nematode, Rotylenchulus reniformis.

    Directory of Open Access Journals (Sweden)

    Seloame T Nyaku

    Full Text Available The 18S rRNA gene is fundamental to cellular and organismal protein synthesis and because of its stable persistence through generations it is also used in phylogenetic analysis among taxa. Sequence variation in this gene within a single species is rare, but it has been observed in few metazoan organisms. More frequently it has mostly been reported in the non-transcribed spacer region. Here, we have identified two sequence variants within the near full coding region of 18S rRNA gene from a single reniform nematode (RN Rotylenchulus reniformis labeled as reniform nematode variant 1 (RN_VAR1 and variant 2 (RN_VAR2. All sequences from three of the four isolates had both RN variants in their sequences; however, isolate 13B had only RN variant 2 sequence. Specific variable base sites (96 or 5.5% were found within the 18S rRNA gene that can clearly distinguish the two 18S rDNA variants of RN, in 11 (25.0% and 33 (75.0% of the 44 RN clones, for RN_VAR1 and RN_VAR2, respectively. Neighbor-joining trees show that the RN_VAR1 is very similar to the previously existing R. reniformis sequence in GenBank, while the RN_VAR2 sequence is more divergent. This is the first report of the identification of two major variants of the 18S rRNA gene in the same single RN, and documents the specific base variation between the two variants, and hypothesizes on simultaneous co-existence of these two variants for this gene.

  4. Characterization of the two intra-individual sequence variants in the 18S rRNA gene in the plant parasitic nematode, Rotylenchulus reniformis.

    Science.gov (United States)

    Nyaku, Seloame T; Sripathi, Venkateswara R; Kantety, Ramesh V; Gu, Yong Q; Lawrence, Kathy; Sharma, Govind C

    2013-01-01

    The 18S rRNA gene is fundamental to cellular and organismal protein synthesis and because of its stable persistence through generations it is also used in phylogenetic analysis among taxa. Sequence variation in this gene within a single species is rare, but it has been observed in few metazoan organisms. More frequently it has mostly been reported in the non-transcribed spacer region. Here, we have identified two sequence variants within the near full coding region of 18S rRNA gene from a single reniform nematode (RN) Rotylenchulus reniformis labeled as reniform nematode variant 1 (RN_VAR1) and variant 2 (RN_VAR2). All sequences from three of the four isolates had both RN variants in their sequences; however, isolate 13B had only RN variant 2 sequence. Specific variable base sites (96 or 5.5%) were found within the 18S rRNA gene that can clearly distinguish the two 18S rDNA variants of RN, in 11 (25.0%) and 33 (75.0%) of the 44 RN clones, for RN_VAR1 and RN_VAR2, respectively. Neighbor-joining trees show that the RN_VAR1 is very similar to the previously existing R. reniformis sequence in GenBank, while the RN_VAR2 sequence is more divergent. This is the first report of the identification of two major variants of the 18S rRNA gene in the same single RN, and documents the specific base variation between the two variants, and hypothesizes on simultaneous co-existence of these two variants for this gene.

  5. Roles of Steroids in Nematodes

    Science.gov (United States)

    The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

  6. Effect of herd management on the contamination of night holding areas (correos) and infections with gastrointestinal nematodes of N'Dama cattle in The Gambia.

    Science.gov (United States)

    Kaufmann, J; Komma, A; Pfister, K

    1995-05-01

    The densities of infective nematode larvae (L3/m2) in the night holding places (locally called "correos") of 2 traditionally kept N'Dama herds were estimated at weekly intervals throughout an entire rainy season. Herd 1 moved correos every 3 weeks whereas herd 2 remained in the same area for most of the rainy season. Removal to a new correo was invariably accompanied by a drastic drop of L3/m2. Conversely, L3/m2 increased rapidly up to values of more than 1,000 when the herds used the same night holding place for more than 3 weeks. Calves kept in herds with frequent changes of the correo showed significantly lower nematode egg counts and higher growth rates during the rainy season, combined with a reduced weight loss during the following dry season. The results of this study indicate that a regular frequent change of the correo is an effective method of reducing nematode infection risk and increasing calf growth and that this might be a sustainable part of an integrated strategic programme to control gastrointestinal nematode infections wherever correos are used.

  7. Nematode cholinergic pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  8. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes.

    Science.gov (United States)

    Piśkiewicz, Anna M; Duyts, Henk; Berg, Matty P; Costa, Sofia R; van der Putten, Wim H

    2007-06-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis is capable of reducing the performance of the dominant grass Ammophila arenaria (Marram grass). However, field surveys show that populations of this nematode usually are controlled to nondamaging densities, but the control mechanism is unknown. In the present study, we first established that T. ventralis populations are top-down controlled by soil biota. Then, selective removal of soil fauna suggested that soil microorganisms play an important role in controlling T. ventralis. This result was confirmed by an experiment where selective inoculation of microarthropods, nematodes and microbes together with T. ventralis into sterilized dune soil resulted in nematode control when microbes were present. Adding nematodes had some effect, whereas microarthropods did not have a significant effect on T. ventralis. Our results have important implications for the appreciation of herbivore controls in natural soils. Soil food web models assume that herbivorous nematodes are controlled by predaceous invertebrates, whereas many biological control studies focus on managing nematode abundance by soil microorganisms. We propose that soil microorganisms play a more important role than do carnivorous soil invertebrates in the top-down control of herbivorous ectoparasitic nematodes in natural ecosystems. This is opposite to many studies on factors controlling root-feeding insects, which are supposed to be controlled by carnivorous invertebrates, parasitoids, or entomopathogenic nematodes. Our conclusion is that the ectoparasitic nematode T. ventralis is potentially able to limit productivity of the dune grass A. arenaria but that soil organisms, mostly microorganisms, usually prevent the

  9. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    Science.gov (United States)

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  10. Evaluación biológica del manejo de picudos y nematodos fitopatógenos en plátano (Musa AAB Biological evaluation of the management of borers and phytopathogenic nematodes of plantain (Musa AAB

    Directory of Open Access Journals (Sweden)

    Carolina González Cardona

    2009-10-01

    Full Text Available El trabajo se desarrolló en la granja Montelindo, municipio de Palestina (Caldas a 5° 05' N y 75° 40' O, a 1010 m.s.n.m., 23.5 °C, precipitación anual de 2100 mm y humedad relativa de 76%, con el fin de generar información sobre el manejo de picudos y nematodos fitoparásitos del plátano. Se usó un diseño en bloques completos al azar con cuatro tratamientos por bloque, tres repeticiones y 24 plantas por repetición. Para el manejo de los picudos se hicieron aplicaciones de Carbofurán, Beauveria bassiana y Metarhizium anisopliae en trampas tipo columna. Para el control de nematodos se hicieron aplicaciones en el suelo de Carbofurán y dos cepas comerciales de Paecilomyces lilacinus. Se evaluaron el número de adultos de picudos en trampas, la infección de estos por los hongos empleados y la población de nematodos en suelo y raíces. Se encontró que las trampas tratadas con Carbofurán fueron significativamente más efectivas para la captura de insectos. En laboratorio se estableció que M. anisopliae tuvo una mejor capacidad para infectar adultos del insecto en el campo. La población de nematodos fue menor en suelo y raíces de las plantas tratadas con Carbofurán. Paecilomyces lilacinus no fue efectivo para reducir las poblaciones de nematodos. Los géneros de nematodos predominantes fueron Radopholus, Pratylenchus, Meloidogyne y Helicotylenchus.This work was carried out at the ‘Montelindo’ farm, municipality of Palestina (Department of Caldas, Colombia, located at 5° 05' N and 75° 40' W, at 1010 m.a.s.l., 23.5 °C, with 2100 mm of annual rainfall, and relative humidity of 76%, in order to generate information on the management of borers and parasitic nematodes of the plantain. A completely randomised block experimental design was used, with four treatments per block, three replicates and 24 plants per replicate. For the management of borers, applications of Carbofuran, Beauveria bassiana and Metarhizium anisopliae were made

  11. Studies on the management of root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex of green gram, Vigna radiata cv ML-1108

    Institute of Scientific and Technical Information of China (English)

    HASEEB Akhtar; SHARMA Anita; SHUKLA Prabhat Kumar

    2005-01-01

    Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil,bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran and A. indica seed powder increased plant growth and yield significantly more in comparison to bavistin and P.fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.

  12. Reflections on plant and soil nematode ecology: past, present and future.

    Science.gov (United States)

    Ferris, Howard; Griffiths, Bryan S; Porazinska, Dorota L; Powers, Thomas O; Wang, Koon-Hui; Tenuta, Mario

    2012-06-01

    The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of interactions between organisms, and of organisms with their environments. In particular, the C. elegans genetic model, nematode faunal analysis and nematode metagenetic analysis can be used by ecologists generally and not restricted to nematologists.

  13. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    Science.gov (United States)

    Dutta, Tushar K.; Papolu, Pradeep K.; Banakar, Prakash; Choudhary, Divya; Sirohi, Anil; Rao, Uma

    2015-01-01

    Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60–80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants. PMID:25883594

  14. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    Directory of Open Access Journals (Sweden)

    Tushar Kanti Dutta

    2015-04-01

    Full Text Available Root-knot nematodes (Meloidogyne incognita cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco and soybean that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1, was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.

  15. Alternatives to anthelmintics for the control of nematodes in livestock.

    Science.gov (United States)

    Stear, M J; Doligalska, M; Donskow-Schmelter, K

    2007-02-01

    Efficient and welfare-friendly livestock production demands the control of nematode infection. Current control measures rely upon anthelmintic treatment but are threatened by the widespread evolution of drug-resistance in parasite populations. Several methods have been advocated to control nematodes without relying on effective anthelmintics. These include grazing management, biological control, nutritional supplementation, vaccination, and genetic approaches. Each method has its advantages and disadvantages. There are several grazing management schemes that can reduce the severity of infection but they are insufficient on their own to control infection. Biological control includes the use of predatory fungi to control nematode populations and the use of pasture species that can reduce the intensity of infection. Fungi can control nematodes but the current requirement for daily feeding means that this approach will be most useful for animals that are handled daily. Feeding supplementary protein can control nematode infection. The method is simple but can be expensive and may not be cost-effective for some marginal enterprises. Genetic approaches include the use of resistant breeds and selective breeding. Some breeds will thrive in conditions that kill animals from other breeds but substitution of resistant breeds is not always feasible. Selective breeding is effective and inexpensive but requires a high level of expertise. The most appropriate method or set of methods to minimize the adverse consequences of nematode infection may vary among farms.

  16. New frontiers in nematode ecology.

    Science.gov (United States)

    Ferris, H

    1993-09-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology.

  17. Intestinal nematodes: biology and control.

    Science.gov (United States)

    Epe, Christian

    2009-11-01

    A variety of nematodes occur in dogs and cats. Several nematode species inhabit the small and large intestines. Important species that live in the small intestine are roundworms of the genus Toxocara (T canis, T cati) and Toxascaris (ie, T leonina), and hookworms of the genus Ancylostoma (A caninum, A braziliense, A tubaeforme) or Uncinaria (U stenocephala). Parasites of the large intestine are nematodes of the genus Trichuris (ie, whipworms, T vulpis). After a comprehensive description of their life cycle and biology, which are indispensable for understanding and justifying their control, current recommendations for nematode control are presented and discussed thereafter.

  18. Resistance and resilience of traditionally managed West African Dwarf goats from the savanna zone of northern Nigeria to naturally acquired trypanosome and gastrointestinal nematode infections.

    Science.gov (United States)

    Behnke, J M; Chiejina, S N; Musongong, G A; Nnadi, P A; Ngongeh, L A; Abonyi, F O; Fakae, B B

    2011-03-01

    A survey was conducted of gastrointestinal nematode infections and trypanosomosis in Nigerian West African Dwarf (WAD) goats from the savanna region of the country. Animals were screened at two markets, Gboko and Akpagher, from the beginning of April until the end of September, coinciding with the end of the dry season and the first 5 months of the wet season. Of 1054 goats that were examined, 80.5% carried gastrointestinal (GI) nematodes belonging to the genera Haemonchus (61.0%), Oesophagostomum (21.0%) and Trichostrongylus (17.9%). Faecal egg counts (FEC) increased very slowly but significantly from April to maximum levels in September, and varied marginally between the two market sources. The majority of goats (68.8 and 70.1% at the two markets) had low FEC not exceeding 50 eggs/g (epg). FEC did not differ significantly between the sexes or between age classes. Packed cell volume (PCV) also declined significantly with month of the study, but was affected by host sex (a significant month x sex interaction) being generally higher in male animals throughout the period. There was a highly significant negative correlation between log₁₀(FEC+1) and PCV, when all other factors had been taken into account. Body condition scores (BCS) also declined with month of the study, but there was a marked difference between the two sexes, with male animals generally showing a greater stability of BCS across the months compared with females. Trypanosome infections were found in only 4% of the goats and only during the rainy season. Most infections (92.86%) were caused by Trypanosoma brucei alone although T. vivax and T. congolense were occasionally detected. Overall, the majority of goats sampled each month maintained generally good body condition (BCS 3.0-5.0), normal or slightly reduced PCV, even when concurrently infected with trypanosomes and GI nematodes. However, four concurrently infected goats showed signs of overt anaemia during periods of peak infection, during the

  19. Bacteria can mobilize nematode-trapping fungi to kill nematodes.

    Science.gov (United States)

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-12-16

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode-predatory form; this predacious form is characterized by formation of specialized cellular structures or 'traps'. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator-prey interactions in prey defense mechanisms.

  20. Temperature-based bioclimatic parameters can predict nematode metabolic footprints.

    Science.gov (United States)

    Bhusal, Daya Ram; Tsiafouli, Maria A; Sgardelis, Stefanos P

    2015-09-01

    Nematode metabolic footprints (MFs) refer to the lifetime amount of metabolized carbon per individual, indicating a connection to soil food web functions and eventually to processes supporting ecosystem services. Estimating and managing these at a convenient scale requires information upscaling from the soil sample to the landscape level. We explore the feasibility of predicting nematode MFs from temperature-based bioclimatic parameters across a landscape. We assume that temperature effects are reflected in MFs, since temperature variations determine life processes ranging from enzyme activities to community structure. We use microclimate data recorded for 1 year from sites differing by orientation, altitude and vegetation cover. At the same sites we estimate MFs for each nematode trophic group. Our models show that bioclimatic parameters, specifically those accounting for temporal variations in temperature and extremities, predict most of the variation in nematode MFs. Higher fungivorous and lower bacterivorous nematode MFs are predicted for sites with high seasonality and low isothermality (sites of low vegetation, mostly at low altitudes), indicating differences in the relative contribution of the corresponding food web channels to the metabolism of carbon across the landscape. Higher plant-parasitic MFs were predicted for sites with high seasonality. The fitted models provide realistic predictions of unknown cases within the range of the predictor's values, allowing for the interpolation of MFs within the sampled region. We conclude that upscaling of the bioindication potential of nematode communities is feasible and can provide new perspectives not only in the field of soil ecology but other research areas as well.

  1. Intraocular nematode with diffuse unilateral subacute neuroretinitis: case report

    Directory of Open Access Journals (Sweden)

    Zakariah Sakinah

    2011-06-01

    Full Text Available Abstract Background Live intraocular nematode is a rare occurrence. Nematode can migrate actively within the eye, creating visual symptoms and damaging ocular tissue. Case presentation A 26-year old man presented with painless reduced vision of the left eye for one week duration. It was associated with floaters. Visual acuity on the left eye was hand movement. Anterior segment examination was normal with normal intra-ocular pressure. Fundus examination showed a live nematode lying subretinally at the macular area with macular oedema and multifocal chorioretinal lesions at peripheral retina. There was no vitritis, vasculitis or any retinal hemorrhage. Systemic examination revealed normal findings and laboratory studies only showed leucocytosis with normal eosinophil count and negative serum toxocara antibody. The diagnosis of introcular nematode with diffuse unilateral subacute neuroretinitis was made. He was treated with oral anti-helminths and a course of oral steroid at a reducing dose. The nematode had died evidenced by its immobility during the treatment and finally disintegrated, leaving macular oedema with mottling appearance and mild hyperpigmentation. Multifocal chorioretinal lesions had also resolved. However despite treatment his visual acuity during follow-up had remained poor. Conclusions Cases of intraocular nematode, though not commonly encountered, continue to present the ophthalmologist with the problem of diagnosis and management and hence poorer prognosis to the patient.

  2. A PCR test to detect the cereal root-knot nematode Meloidogyne naasi

    NARCIS (Netherlands)

    Zijlstra, C.; Hoof, van R.A.; Donkers-Venne, D.

    2004-01-01

    The cereal root-knot nematode Meloidogyne naasi can cause serious cereal crop losses. The nematode is also found in agricultural fields where non-host crops are grown. Control of M. naasi can be based on preventing its spread, host resistance and crop management as well as on the design of crop rota

  3. Social networks of educated nematodes

    Science.gov (United States)

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  4. ORGANIC VS CONVENTIONAL: SOIL NEMATODE COMMUNITY STRUCTURE AND FUNCTION.

    Science.gov (United States)

    Kapp, C; Storey, S G; Malan, A P

    2014-01-01

    Global increases in human population are creating an ever-greater need for food production. Poor soil management practices have degraded soil to such an extent that rapidly improved management practices is the only way to ensure future food demands. In South Africa, deciduous fruit producers are realising the need for soil health, and for an increased understanding of the benefits of soil ecology, to ensure sustainable fruit production. This depends heavily on improved orchard management. Conventional farming relies on the addition of artificial fertilizers, and the application of chemicals, to prevent or minimise, the effects of the soil stages of pest insects, and of plant-parasitic nematodes. Currently, there is resistance toward conventional farming practices, which, it is believed, diminishes biodiversity within the soil. The study aimed to establish the soil nematode community structure and function in organically, and conventionally, managed deciduous fruit orchards. This was done by determining the abundance, the diversity, and the functionality of the naturally occurring free-living, and plant-parasitic, nematodes in deciduous fruit orchards in the Western Cape province of South Africa. The objective of the study was to form the basis for the use of nematodes as future indicators of soil health in deciduous fruit orchards. Orchards from neighbouring organic, and conventional, apricot farms, and from an organic apple orchard, were studied. All the nematodes were quantified, and identified, to family level. The five nematode-classified trophic groups were found at each site, while 14 families were identified in each orchard, respectively. Herbivores were dominant in all the orchards surveyed. Organic apples had the fewest herbivores and fungivores, with the highest number of carnivores. When comparing organic with conventional apricot orchards, higher numbers of plant-parasitic nematodes were found in the organic apricot orchards. The Maturity Index (MI

  5. Rotação e sucessão de culturas para o manejo do nematoide reniforme em área de produção de soja

    Directory of Open Access Journals (Sweden)

    Hugo Márcio Leandro

    2015-06-01

    Full Text Available O nematoide reniforme (Rotylenchulus reniformis tem se tornado crescente problema fitossanitário da cultura da soja. Considerando a limitada disponibilidade de cultivares de soja que aliem resistência ao nematoide a outras características agronômicas desejáveis, estuda-se a possibilidade de utilização de manejo cultural para seu controle. Este trabalho visou avaliar o efeito da rotação de culturas no verão com milho, Crotalaria ochroleuca ou soja; e o manejo de entressafra, com Brachiaria ruziziensis como espécie de cobertura ou pousio. O experimento foi implantado em solo naturalmente infestado pelo nematoide reniforme (1245 nematoides/200cc de solo em delineamento experimental de blocos ao acaso, com quatro repetições, em esquema fatorial 3x2 (cultivos de verão x manejo de entressafra. Foram avaliadas a densidade populacional do nematoide no solo e sua variação durante as safras e entressafras, bem como a produtividade da soja na safra subsequente à rotação de culturas. Não houve efeito do manejo da entressafra com braquiária sobre o nematoide. A rotação de culturas com milho ou crotalária no verão propiciou redução da densidade populacional do nematoide reniforme em comparação ao monocultivo de soja, com reflexos positivos sobre a produtividade de soja na safra seguinte

  6. Nematode-trapping fungi eavesdrop on nematode pheromones.

    Science.gov (United States)

    Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C; Sternberg, Paul W

    2013-01-07

    The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior. Here, we show that nematophagous fungi, natural predators of soil-dwelling nematodes, can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap formation in response to their prey. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived conditions. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey coevolution. We anticipate that these findings will have broader implications for understanding other interkingdom interactions involving nematodes, which are found in almost any ecological niche on Earth.

  7. In vitro evaluation of antibacterial and immunomodulatory activities of Pelargonium reniforme, Pelargonium sidoides and the related herbal drug preparation EPs 7630.

    Science.gov (United States)

    Kolodziej, Herbert; Kiderlen, Albrecht F

    2007-01-01

    The importance of Pelargonium species, most notably Pelargonium reniforme and Pelargonium sidoides, in traditional medicine in the Southern African region is well documented. Nowadays, a modern aqueous-ethanolic formulation of the roots of P. sidoides (EPs) 7630) is successfully employed for the treatment of ear, nose and throat disorders as well as respiratory tract infections. To provide a scientific basis of its present utilization in phytomedicine, EPs 7630, extracts and isolated constituents of the titled Pelargoniums with emphasis on P. sidoides were evaluated for antibacterial activity and for their effects on nonspecific immune functions. The samples exhibited merely moderate direct antibacterial capabilities against a spectrum of Gram-positive and Gram-negative bacteria. Functional bioassays including an in vitro model for intracellular diseases, a fibroblast-lysis assay (tumour necrosis factor (TNF) activity), a fibroblast-virus protection assay (IFN activity) and a biochemical assay for nitric oxides revealed significant immunomodulatory properties. Gene expression experiments (iNOS, IFN-alpha, IFN-gamma, TNF-alpha, Interleukin (IL)-1, IL-10, IL12, IL-18) not only confirmed functional data, they also clearly showed differences in the response of infected macrophages when compared to that of noninfected cells. ELISA confirmed the protein production of TNF-alpha, IL-1alpha and IL-12, while FACS analyses reaffirmed the cytokines IL-1alpha and IL-12 at the singular cell level. The current data provide convincing support for the improvement of immune functions at various levels, hence, validating the medicinal uses of EPs 7630. Despite considerable efforts, the remedial effects cannot yet be related to a chemically defined principle.

  8. Social Networks of Educated Nematodes.

    Science.gov (United States)

    Willett, Denis S; Alborn, Hans T; Duncan, Larry W; Stelinski, Lukasz L

    2015-09-25

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments.

  9. Using nematodes in soil ecotoxicology.

    Science.gov (United States)

    Sochová, Ivana; Hofman, Jakub; Holoubek, Ivan

    2006-04-01

    Nematodes represent a very abundant group of soil organisms and non-parasitic species are important for soil quality and in the soil food web. In recent years, it has been shown that nematodes are appropriate bioindicators of soil condition and they are also suitable organisms for laboratory toxicity testing. The aims of this paper are to overview and critically assess methods and approaches for researching soil nematode ecotoxicology. In natural ecosystems, nematode abundance and community structure analyses were proved to be sensitive indicators of stress caused by soil pollutants and ecological disturbance. Community structure analyses may be approached from a functional or ecological point of view; species are divided into groups according to their feeding habits or alternatively the maturity index is calculated according to their ecological strategy. Many environmental factors have the potential to affect nematode community, which consequently results in high space and time variability. This variance is major handicap in field ecotoxicological studies because pollutant-nematode relationships are obscured. For prospective risk assessment of chemicals, several toxicity tests with nematodes were developed and are increasingly used. Sensitivity of these tests is comparable to tests with other soil species (e.g. enchytraeids, earthworms and springtails) while tests are less demanding to space and time. Most studies have focused on metal toxicity but organic compounds are almost overlooked. Endpoints used in tests were often mortality, reproduction or movement, but more sublethal endpoints such as feeding or biomarkers have been used recently too. Although there is an increasing amount of knowledge in soil nematode ecotoxicology, there is still a lot of various issues in this topic to research.

  10. Grazing sericea lespedeza for control of gastrointestinal nematodes in lambs

    Science.gov (United States)

    Alternatives to chemical dewormers are needed to counter anthelmintic resistance and improve organic management systems. The objective was to examine the effectiveness of grazing sericea lespedeza (SL) compared with grass pastures for control of gastrointestinal nematodes (GIN) in lambs. In Experi...

  11. Management of disease complex caused by root knot nematode and root wilt fungus on pigeonpea through soil organically enriched with Vesicular Arbuscular Mycorrhiza, karanj (Pongamia pinnata) oilseed cake and farmyard manure.

    Science.gov (United States)

    Goswami, B K; Pandey, Rajesh Kumar; Goswami, Jaideep; Tewari, D D

    2007-11-01

    This investigation was undertaken to compare the percentage response of colonization and development of VA-Mycorrhiza (Glomus fasciculatum) on a number of pulse crops viz. cowpea, chickpea, soybean, pigeonpea and lentil under glasshouse conditions. Among the above-mentioned crops, pigeonpea exhibited the best performance and was selected for further studies. In this host the development and colonization percentage of G. fasciculatum was investigated under two separate substrates i. e. soil amended with FYM and karanj oilseed cake keeping a control treatment of field soil. A third treatment amended with karanj oilseed cake and farm yard manure (FYM) was also kept which responded best in terms of colonization percentage. This treatment showing improved plant health as well as integration with G. fasciculatum was selected as an ideal treatment for the management of disease complex caused by root knot nematode, Meloidogyne incognita and root wilt fungus, Fusarium udum on pigeonpea. Thus the treatment constituting FYM, karanj oilseed cake and VA-Mycorrhiza reduced the disease incidence caused by both maladies to a great extent with the most promising improvement in plant growth parameters as compared to all others. The present investigation, in addition to proposing an ideal eco-friendly treatment for the management of this disease complex also proposed an excellent medium for the proliferation of the obligate bio-protectant, G. fasciculatum.

  12. The Geological Record of Parasitic Nematode Evolution.

    Science.gov (United States)

    Poinar, George O

    2015-01-01

    This chapter discusses the evolutionary history of nematode parasites of invertebrates, vertebrates and plants based on fossil remains in amber, stone and coprolites dating from the Palaeozoic to the Holocene. The earliest parasitic nematode is a primitive plant parasite from the Devonian. Fossil invertebrate-parasitic nematodes first appeared in the Early Cretaceous, while the earliest fossil vertebrate-parasitic nematodes are from Upper Triassic coprolites. Specific examples of fossil nematode parasites over time are presented, along with views on the origin and evolution of nematodes and their hosts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Research on plant-parasitic nematode biology conducted by the United States Department of Agriculture-Agricultural Research Service.

    Science.gov (United States)

    Chitwood, David J

    2003-01-01

    The recent de-registration of several chemical nematicides and the impending loss of methyl bromide from the pest-control market necessitate the development of new methods for controlling nematode-induced crop damage. One approach for developing novel target-specific controls is by exploiting fundamental differences between the biological processes of nematodes and their host plants. Researchers of the Agricultural Research Service (ARS) of the US Department of Agriculture are actively exploring these differences. Research accomplishments include the discovery of heat shock protein genes possibly involved in developmental arrest of the soybean cyst nematode, the identification of neuropeptides and female-specific proteins in the soybean cyst nematode, the disruption of nematode reproduction with inhibitors of nematode sterol metabolism, the development of novel morphological and molecular (heat shock protein genes and the D3 segment of large subunit ribosomal DNA) features useful for nematode identification and classification, and the elucidation of the population genetics of potato cyst nematode pathotypes. In addition, several ARS researchers are investigating biological determinants of nematode response to management strategies utilized in agricultural fields. These collective efforts should lead to new chemical and non-chemical alternatives to conventional nematode control strategies.

  14. Biotechnological application of functional genomics towards plant-parasitic nematode control.

    Science.gov (United States)

    Li, Jiarui; Todd, Timothy C; Lee, Junghoon; Trick, Harold N

    2011-12-01

    Plant-parasitic nematodes are primary biotic factors limiting the crop production. Current nematode control strategies include nematicides, crop rotation and resistant cultivars, but each has serious limitations. RNA interference (RNAi) represents a major breakthrough in the application of functional genomics for plant-parasitic nematode control. RNAi-induced suppression of numerous genes essential for nematode development, reproduction or parasitism has been demonstrated, highlighting the considerable potential for using this strategy to control damaging pest populations. In an effort to find more suitable and effective gene targets for silencing, researchers are employing functional genomics methodologies, including genome sequencing and transcriptome profiling. Microarrays have been used for studying the interactions between nematodes and plant roots and to measure both plants and nematodes transcripts. Furthermore, laser capture microdissection has been applied for the precise dissection of nematode feeding sites (syncytia) to allow the study of gene expression specifically in syncytia. In the near future, small RNA sequencing techniques will provide more direct information for elucidating small RNA regulatory mechanisms in plants and specific gene silencing using artificial microRNAs should further improve the potential of targeted gene silencing as a strategy for nematode management. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  15. Methyl Bromide Alternatives for Control of Root-knot Nematode (Meloidogyne spp.) in Tomato Production in Florida

    Science.gov (United States)

    Desaeger, Johan; Dickson, Donald W.; Locascio, S. J.

    2017-01-01

    The following work was initiated to determine the scope of application methodology and fumigant combinations for increasing efficacy of 1,3-dichloropropene (1,3-D) and metam sodium for management of root-knot nematodes (Meloidogyne spp.) in Florida. A series of five experiments were set up during spring and fall seasons to evaluate the potential of different fumigants, alone or in combination, in polyethylene film tomato production. The most promising chemical alternatives to methyl bromide, in terms of root-knot nematode management, were the combinations 1,3-D-chloropicrin, chloropicrin-proprietary solvent ,and 1,3-D-metam sodium. Sprayed or injected metam sodium generally provided only short-term nematode management and by harvest nematode infection was not different from the nontreated control. Drip-applied metam sodium gave good nematode management under high nematode pressure, but needs further verification to establish (i) the importance of soil moisture and temperature on treatment efficacy and (ii) whether similar management can be obtained with fewer than three drip tubes. Broadcast applications of 1,3-D showed better efficacy as compared to applications on a preformed raised bed. Fumigation did not increase tomato yields in spring when root-knot nematode pressure was low, but during fall all chemical treatments increased yields three to five-fold, as root-knot nematode was a major yield-limiting factor. PMID:28706313

  16. Arrested larval development in cattle nematodes.

    Science.gov (United States)

    Armour, J; Duncan, M

    1987-06-01

    Most economically important cattle nematodes are able to arrest their larval development within the host - entering a period of dormancy or hypobiosis. Arrested larvae have a low death rate, and large numbers can accumulate in infected cattle during the grazing season. Because of this, outbreaks of disease caused by such nematodes can occur at times when recent infection with the parasites could not have occurred, for example during winter in temperature northern climates when cattle are normally housed. The capacity to arrest is a heritable trait. It is seen as an adaptation by the parasite to avoid further development to its free-living stages during times when the climate is unsuitable for free-living survival. But levels of arrestment can vary markedly in different regions, in different cattle, and under different management regimes. Climatic factors, previous conditioning, host immune status, and farm management all seem to affect arrestment levels. In this article, James Armour and Mary Duncan review the biological basis of the phenomenon, and discuss the apparently conflicting views on how it is controlled.

  17. Application and commercialization of nematodes.

    Science.gov (United States)

    Peters, Arne

    2013-07-01

    While nematodes are most commonly known for their negative impact on plants, animals, and humans, there are a number of species which are commercially explored. This review highlights some of the most important success stories for the application of nematodes. They are used as bioindicators in ecological and toxicity studies, as model organisms for elucidating fundamental biological questions and for high throughput screening of drugs. Besides these indirect uses, direct applications include the use of Beddingia siricidicola against a major forest pest and the commercialization of Steinernema, Heterorhabditis, and Phasmarhabditis as biological pest control products. New directions for the commercialization of nematodes are the use as living food, specifically loaded with essential nutrients for various fish and shrimp larvae. Even human parasites or closely related species have been successfully used for curing autoimmune disorders and are currently in the process of being developed as drugs. With the striving development of life sciences, we are likely to see more applications for nematodes in the future. A prerequisite is that we continue to explore the vast number of yet undiscovered nematode species.

  18. Impact of conservation tillage on nematode populations.

    Science.gov (United States)

    Minton, N A

    1986-04-01

    Literature reporting the development of conservation tillage and the research that has been conducted on nematode control in crops grown in conservation tillage systems is reviewed. Effects of different types of conservation tillage on population densities of various nematode species in monocropping and multicropping systems, effects of tillage on nematode distribution in the soil profile, effects of conservation tillage on nematode control, and the role of nematology in conservation tillage research are discussed.

  19. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes.

    Science.gov (United States)

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C J

    2015-02-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes.

  20. Entomopathogenic nematodes in agricultural areas in Brazil.

    Science.gov (United States)

    de Brida, Andressa Lima; Rosa, Juliana Magrinelli Osório; Oliveira, Cláudio Marcelo Gonçalves de; Castro, Bárbara Monteiro de Castro E; Serrão, José Eduardo; Zanuncio, José Cola; Leite, Luis Garrigós; Wilcken, Silvia Renata Siciliano

    2017-04-06

    Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas.

  1. Impact of sewage disposal on a nematode community of a tropical sandy beach

    Digital Repository Service at National Institute of Oceanography (India)

    Nanajkar, M.; Ingole, B.S.

    oxygen conditions. Figure 4: Cumulative dominance curve for nematode species at the sampling locations. A combination of Maturity Index (MI) and Shannon- Wiener diversity Index (H’) are known to be good tools in pollution monitoring, especially... as an environmental management strategy. Nevertheless, laboratory culture of opportunistic nematode species such as Daptonema sp could be a handy tool for pollution studies, especially for exploring the mitigating measures. Efforts are therefore being made to 8...

  2. Plant Nematodes Occurring in Arkansas

    OpenAIRE

    Wehunt, E. J.; Golden, A. M.; Robbins, R. T.

    1989-01-01

    A total of 110 species of plant nematodes were found in various habitats in Arkansas. Thirty species from 19 genera are reported here for the first time. Included in the new reports are the known plant pathogens Criconemella onoense, Hirshmanniella oryzae, Longidorus elongatus, and Pratylenchus pratensis.

  3. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and

  4. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and s

  5. Can entomophagous nematodes slow the spread of invasive pest populations? The case study of Beddingia siricidicola released for the management of Sirex noctilio

    Science.gov (United States)

    Juan C. Corley; José M. Villacide; Andrew M. Liebhold

    2014-01-01

    Though rarely used in this way, biological control could potentially be exploited for managing spread of invasive species. Because spread of invasive species emerges from the combined action of population growth and dispersal, natural enemies that affect either of these processes should also affect spread. Dispersal of parasitoid species plays a key role in determining...

  6. Diversity and Dynamics of Soil Free-Living Nematode Populations in a Mediterranean Agroecosystem

    Institute of Scientific and Technical Information of China (English)

    LIANG Wen-Ju; I.LAVIAN; S.PEN-MOURATOV; Y.STEINBERGER

    2005-01-01

    To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0-10 cm and 10-20 cm depths were collected during the growing season of carrot. Indices were used to compare and assess the response of soil free-living nematode communities to agricultural management. Eighteen nematode families and 20 genera were observed during the growing period, with Cephalobus, Rhabditidae, Aphelenchus, Tylenchus, and Dorylaimus being the dominant genera/families.During the planting, mid-season and post-harvest periods the total number of nematodes at both depths was significantly lower (P < 0.01) in the carrot treatment than in the control plots, while during the harvest period at both depths total nematodes and bacterivores were significantly higher in the treatment plots (P < 0.01). The values of the maturity index (MI) at both depths were found to be significantly lower in the treatment plots than in the control plots during the pre-planting period (P < 0.05). Overall, WI, MI and PPI were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in a Mediterranean agroecosystem.

  7. Prevalence, intensity and risk factors of infestation with major gastrointestinal nematodes in equines in and around Shashemane, Southern Ethiopia.

    Science.gov (United States)

    Seyoum, Zewdu; Tesfaye, Mulualem; Derso, Samuel

    2015-12-01

    Prevalence, intensity and risk factors of major gastrointestinal nematode infestation in equines were studied through a cross-sectional survey in 384 equids from October 2013 to April 2014 in and around Shashemane, southern Ethiopia. Three hundred and fifteen equids (82 %) were demonstrated harbouring one or more gastrointestinal (GIT) nematodes using the faecal flotation technique. The prevalence of GIT nematode infestation was 73.4, 85 and 86.5 % for horses, mules and donkeys, respectively. The identified nematodes were strongyle type (73.4 %), Parascaris equorum (21.4 %) and Oxyuris equi (4.4 %). Species of equines had a significant (χ (2) = 9.35, P nematode infestation. Donkeys were two times (OR = 2.3, 95 % CI 1.27-4.28, P nematode infestation than horses. Moreover, donkeys had the highest mean faecal egg counts (1831.2 egg per gram (EPG)) followed by mules (915.7 EPG) and horses (772.5 EPG). There was a significant association (P nematode infestation in equines. Moreover, suitable tropical climatic conditions, low level of management and owners' awareness, and poor animal health services are expected to contribute for high nematode infestation. Therefore, emphasis should be given to awareness creation about the strategic deworming, animal welfare and management.

  8. Plant and soil nematodes: societal impact and focus for the future.

    Science.gov (United States)

    Barker, K R; Hussey, R S; Krusberg, L R; Bird, G W; Dunn, R A; Ferris, H; Ferris, V R; Freckman, D W; Gabriel, C J; Grewal, P S; Macguidwin, A E; Riddle, D L; Roberts, P A; Schmitt, D P

    1994-06-01

    Plant and soil nematodes significandy impact our lives. Therefore, we must understand and manage these complex organisms so that we may continue to develop and sustain our food production systems, our natural resources, our environment, and our quality of life. This publication looks specifically at soil and plant nematology. First, the societal impact of nematodes and benefits of nematology research are briefly presented. Next, the opportunities facing nematology in the next decade are outlined, as well as the resources needed to address these priorities. The safety and sustainability of U.S. food and fiber production depends on public and administrative understanding of the importance of nematodes, the drastic effects of nematodes on many agricultural and horticultural crops, and the current research priorities of nematology.

  9. Nematode response to metal, PAHs and organic enrichment in tourist marinas of the Mediterranean Sea.

    Science.gov (United States)

    Moreno, M; Albertelli, G; Fabiano, M

    2009-08-01

    The structure of nematode assemblages was investigated in the sediments of two different tourist marinas in the Mediterranean Sea and related to pollution variables. Nematode densities and generic compositions were determined, as were concentrations of heavy metals, PAHs and organic matter. Results showed different assemblages at the two marinas, with a dominance of the genera Paralongicyatholaimus and Daptonema. Significant correlations between nematodes and concentrations of environmental contaminants were found. In particular, Paralongicyatholaimus showed a significant negative correlation with Cu concentrations and was almost absent at the stations where higher Cu concentrations were found. The presence of sensitive/tolerant nematode genera represents a promising tool to identify areas subjected to a higher level of disturbance and to define the correct environmental management strategy for harbors.

  10. Experimental Evolution with Caenorhabditis Nematodes

    Science.gov (United States)

    Teotónio, Henrique; Estes, Suzanne; Phillips, Patrick C.; Baer, Charles F.

    2017-01-01

    The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C. briggsae and C. remanei, by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic variation; (2) role of natural selection during transitions from outcrossing to selfing, as well as the maintenance of mixed breeding modes during evolution; and (3) evolution of phenotypic plasticity and its role in adaptation to variable environments, including host–pathogen coevolution. We conclude by suggesting some future directions for which experimental evolution with Caenorhabditis would be particularly informative. PMID:28592504

  11. Survey of Nematodes on Coffee in Hawaii

    OpenAIRE

    Schenck, S; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's ...

  12. The effects of Brassica green manures on plant parasitic and free living nematodes used in combination with reduced rates of synthetic nematicides.

    Science.gov (United States)

    Riga, Ekaterini

    2011-06-01

    Brassica plants once incorporated into soil as green manures have recently been shown to have biofumigant properties and have the potential of controlling plant-parasitic nematodes. In Washington State, plant-parasitic nematodes are successfully managed with synthetic nematicides. However, some of the synthetic nematicides became unavailable recently or their supply is limited leaving growers with few choices to control plant-parasitic nematodes. The objective of this project was to evaluate the effects of Brassica green manures on their own and in combination with reduced rates of synthetic nematicides on plant-parasitic nematodes and free living nematodes. In a greenhouse experiment and field trials in three seasons, Brassica green manures in combination with half the recommended rate of 1,3-dichloropropene (1,3-D, Telone) reduced root knot nematode, Meloidogyne chitwoodi to below detection levels, and reduced lesion nematodes, Pratylenchus penetrans and stubby root nematodes, Paratrichodorus allius, to below economic thresholds. The combination treatments did not affect the beneficial free-living nematode populations and the non-pathogenic Pseudomonas. The total cost of growing and soil-incorporating Brassica crops as green manures in combination with reduced rates of 1,3-D was approximately 35% lower than the present commercial costs for application for the full rate of this fumigant. Integrating conventional management practices with novel techniques fosters sustainability of production systems and can increase economic benefit to producers while reducing chemical input.

  13. Chemical alternatives to methyl bromide for the control of root-knot nematodes in greenhouses.

    Science.gov (United States)

    Giannakou, Ioannis O; Sidiropoulos, Artemios; Prophetou-Athanasiadou, Demetra

    2002-03-01

    The complete phase-out of methyl bromide from use in developed countries by 1 January 2005 will cause many problems in agricultural industries that are now heavily reliant on its use. Three field experiments were established to compare management tactics on tomato and cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Reduction of nematode juveniles in soil and roots to nil detection levels was observed in all plots following soil fumigation with methyl bromide. A significant reduction of nematode juveniles and root-galling index was observed in plots treated with metham-sodium, dazomet and 1,3-dichloropropene compared with the control and plots treated with non-fumigant nematicides. Reduction of the nematode population led to an increase in fruit yield. However, data collected from the second cultivation season indicated that single control methods such as fumigant or contact nematicides alone cannot drastically decrease initial nematode population and those nematodes which escape control lead to population increase by the end of the cropping season.

  14. Performance of arugula (Eruca sativa) as a green manure and trap crop for fungal pathogens and parasitic nematode suppression in potato

    Science.gov (United States)

    Green manures in combination with synthetic nematicides are used to manage plant parasitic nematodes in a potato cropping system. Arugula, Eruca sativa, a Brassica plant, has shown great potential for controlling plant parasitic nematodes as, it has a dual role. Arugula is both a green manure (it co...

  15. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival of nematode

  16. Condensed tannins act against cattle nematodes

    DEFF Research Database (Denmark)

    Novobilský, Adam; Mueller-Harvey, Irene; Thamsborg, Stig Milan

    2011-01-01

    The use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (GIN) in ruminants. Direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat GIN. These anthelmintic properties are mainly associated with ...... extracts. Our results, therefore, indicated that tannin-containing plants could act against cattle nematodes....

  17. Isolation of pristionchus nematodes from beetles.

    Science.gov (United States)

    Rae, Robbie; Schlager, Benjamin; Sommer, Ralf J

    2008-10-01

    INTRODUCTIONIn this procedure, nematodes disembark from a beetle carcass and feed on Escherichia coli OP50. The nematodes are then monitored for a few days and identified using simple morphological characteristics. This method is rapid, easy, and biased for Pristionchus species.

  18. Nematodes ultrastructure: complex systems and processes.

    Science.gov (United States)

    Basyoni, Maha M A; Rizk, Enas M A

    2016-12-01

    Nematode worms are among the most ubiquitous organisms on earth. They include free-living forms as well as parasites of plants, insects, humans and other animals. Recently, there has been an explosion of interest in nematode biology, including the area of nematode ultrastructure. Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm. It appears that the cuticle is a very complex and evolutionarily plastic feature with important functions involving protection, body movement and maintaining shape. They only have longitudinal muscles so; they seem to thrash back and forth. While nematodes have digestive, reproductive, nervous and excretory systems, they do not have discrete circulatory or respiratory systems. Nematodes use chemosensory and mechanosensory neurons embedded in the cuticle to orient and respond to a wide range of environmental stimuli. Adults are made up of roughly 1000 somatic cells and hundreds of those cells are typically associated with the reproductive systems. Nematodes ultrastructure seeks to provide studies which enable their use as models for diverse biological processes including; human diseases, immunity, host-parasitic interactions and the expression of phylogenomics. The latter has, however, not been brought into a single inclusive entity. Consequently, in the current review we tried to provide a comprehensive approach to the current knowledge available for nematodes ultrastructures.

  19. Mechanisms of host seeking by parasitic nematodes.

    Science.gov (United States)

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.

  20. Blends of ascarosides regulate dispersal in nematodes

    Science.gov (United States)

    Blends of ascarosides regulate dispersal in nematodes Presenter: Dr. Fatma Kaplan Dispersal is an important behavior for many organisms. It can easily be observed when infectious juveniles of entomopathogenic nematodes (Steinernema and Heterorhabditis) leave a consumed insect host. Dauer larvae of ...

  1. Biological Control of Nematodes with Bacteria

    Science.gov (United States)

    Biological control of nematodes is receiving increased attention as environmental considerations with the use of nematicides have increased in importance and their high cost prohibits use on many crops. In addition, nematode resistant cultivars are not available for many crops and resistance that i...

  2. Effects of nematicide treatment in combination with solarization on management of the root-knot nematodes on tomato%土壤药剂处理结合阳光消毒防治番茄根结线虫技术评价

    Institute of Scientific and Technical Information of China (English)

    张卓; 彭德良; 黄文坤; 王高峰; 张超; 林雪; 张桂娟; 孙建华

    2011-01-01

    In this study, different soil nematicide treatments in combination with solarization were carried out to evaluate their effects on managing the root-knot nematode Meloidogyne incognita. Five nematicides and dosage were used to evaluate against root-knot nematode in combination with solarization, including dazomet 450 kg/hm2, 1,3-dichloropropene+chlorpicrin 500 L/hm2, metham-sodium 75 L/hm2, fosthiazate 30 kg/hm2 and methyl bromide 340 kg/hm2. Dazomet 450 kg/hm2 and fosthiazate 30 kg/hm2 provided the most effective results. It gave maximal decrease in juveniles of root knot nematode, increase of plant output and economic benefit and minimal damage by diseases. It is a suitable method for the management of tomato root-knot nematode diseases in greenhouse vegetables in Northern China.%为了筛选安全、高效、实用的化学防治技术,对国内外生产的5种杀线虫剂(棉隆、1,3-二氯丙烯·氯化苦、威百亩、噻唑磷、溴甲烷)土壤处理结合阳光消毒防治番茄根结线虫的效果进行了评价.结果表明,使用98%棉隆微粒剂450kg/h㎡或10%噻唑磷颗粒剂30kg/h㎡防治番茄根结线虫(Meloidogyne incognita),结合夏季高温进行阳光消毒,能有效地降低番茄根结线虫的数量,减轻根结线虫的危害程度,节省农户的生产成本,提高番茄的产量和农户的经济效益,是夏季防治番茄根结线虫的有效措施.

  3. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  4. Improved nematode extraction from carrot disk culture.

    Science.gov (United States)

    Kaplan, D T; Davis, E L

    1990-07-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO-7H0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures.

  5. Nondestructive imaging of plant-parasitic nematode development and host response to nematode pathogenesis.

    Science.gov (United States)

    Dinh, Phuong T Y; Knoblauch, Michael; Elling, Axel A

    2014-05-01

    The secluded lifestyle of endoparasitic plant nematodes hampers progress toward a comprehensive understanding of plant-nematode interactions. A novel technique that enables nondestructive, long-term observations of a wide range of live nematodes in planta is presented here. As proof of principle, Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne chitwoodi were labeled fluorescently with PKH26 and used to infect Arabidopsis thaliana grown in microscopy rhizosphere chambers. Nematode behavior, development, and morphology were observed for the full duration of each parasite's life cycle by confocal microscopy for up to 27 days after inoculation. PKH26 accumulated in intestinal lipid droplets and had no negative effect on nematode infectivity. This technique enabled visualization of Meloidogyne gall formation, nematode oogenesis, and nematode morphological features, such as the metacorpus, vulva, spicules, and cuticle. Additionally, microscopy rhizosphere chambers were used to characterize plant organelle dynamics during M. chitwoodi infection. Peroxisome abundance strongly increased in early giant cells but showed a marked decrease at later stages of feeding site development, which suggests a modulation of plant peroxisomes by root-knot nematodes during the infection process. Taken together, this technique facilitates studies aimed at deciphering plant-nematode interactions at the cellular and subcellular level and enables unprecedented insights into nematode behavior in planta.

  6. Genetic analysis of root-knot nematode resistance in potato

    NARCIS (Netherlands)

    Draaistra, J.

    2006-01-01

    The development of potato varieties with resistance towards the potato cyst nematode, allowed a dramatic decrease of the use of nematicides. Subsequently the population of the free living nematodes and the root-knot nematodes ( Meloidogyne spp.) has increased. Among the root-knot nematodes, three Me

  7. Nematode pests threatening soybean production in South Africa, with reference to Meloidogyne

    Directory of Open Access Journals (Sweden)

    Hendrika Fourie

    2015-09-01

    Full Text Available The area planted to soybean in South Africa has increased by 54% since the 2009 growing season, mainly as a result of the increasing demand for protein-rich food and fodder sources. Moreover, the introduction of advanced technology, namely the availability of genetically modified herbicide tolerant soybean cultivars also contributed towards increased soybean production. The omnipresence of plant-parasitic nematodes in local agricultural soils, however, poses a threat to the sustainable expansion and production of soybean and other rotation crops. Meloidogyne incognita and M. javanica are the predominant nematode pests in local soybean production areas and those where other grain-, legume- and/or vegetable crops are grown. The lack of registered nematicides for soybean locally, crop production systems that are conducive to nematode pest build-ups as well as the limited availability of genetic host plant resistance to root-knot nematode pests, complicate their management. Research aimed at various aspects related to soybean-nematode research, namely, audits of nematode assemblages associated with the crop, identification of genetic host plant resistance in soybean germplasm to M. incognita and M. javanica, the use of molecular markers that are linked to such genetic resistance traits as well as agronomic performance of pre-released cultivars that can be valuable to producers and the industry are accentuated in this review. Evaluation of synthetically-derived as well as biological-control agents are also discussed as complementary management tactics. It is important that lessons learned through extensive research on soybean-nematode interactions in South Africa be shared with researchers and industries in other countries as they might experience or expect similar problems and/or challenges.

  8. A checklist of nematode parasites from Indonesian murids.

    Science.gov (United States)

    Dewi, Kartika; Purwaningsih, Endang

    2013-01-24

    A checklist of nematode parasites from Indonesian murids with their geographic distribution is presented. This checklist is compiled from three sources: the catalogue of nematode parasites of Museum Zoologicum Bogoriense (unpublished specimens in the collection), data from our previous research and articles on nematodes of Indonesian murids. This checklist is presented as a list of nematode parasites with host information, and a host list with information on their nematodes. This paper reports 38 nominal species of nematodes and 13 species identified to the generic level only. The nematodes reported comprise 32 genera and 17 families parasitizing 32 species of Indonesian murids.

  9. [Nematodes of humans in the Primorye Territory].

    Science.gov (United States)

    Ermolenko, A V; Rumiantseva, E E; Bartkova, A D; Voronok, V M; Poliakova, L F

    2013-01-01

    Nematodes occupy the top in the general pattern of human parasitic diseases in the Primorye Territory. In the south of the Far East, there are a total of 28 nematode species that can parasitize man. However, the authors have identified only 8 nematode-induced diseases, such as ascariasis, enterobiasis, toxocariasis, trichocephaliasis, anisakiasis, trichinosis, dirofilariasis, dioctophymosis. The latter has been found only once in the 1920s. According to official statistical data, the proportion of ascariasis and enterobiasis accounted for 43.8 and 53.5% of the total number of helminthiases, respectively.

  10. IMPORTANT NEMATODE INFECTIONS IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Sri Oemijati

    2012-09-01

    Full Text Available At least 13 species of intestinal nematodes and 4 species of blood and tissue nematodes have been reported infecting man in Indonesia. Five species of intestinal nematodes are very common and highly prevalent, especially in the rural areas and slums of the big cities. Those species are Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Trichuris trichiura and Oxyuris vermicularis, while Strongyloides stercoralis is disappearing. The prevalence of the soil transmitted helminths differs from place to place, depending on many factors such as the type of soil, human behaviour etc. Three species of lymph dwelling filarial worms are known to be endemic, the urban Wuchereria bancrofti is low endemic in Jakarta and a few other cities along the north coast of Java, with Culex incriminated as vector, high endemicity is found in Irian Jaya, where Anopheline mosquitoes act as vectors. Brugia malayi is widely distributed and is still highly endemic in many areas. The zoonotic type is mainly endemic in swampy areas, and has many species of Mansonia mosquitoes as vectors. B.timori so far has been found only in the south eastern part of the archipelago and has Anopheles barbirostris as vector. Human infections with animal parasites have been diagnosed properly only when adult stages were found either in autopsies or removed tissues. Cases of infections with A. caninum, A.braziliense, A.ceylanicum, Trichostrongylus colubriformis, T.axei and Oesophagostomum apiostomum have been desribed from autopsies, while infections with Gnathostoma spiningerum have been reported from removed tissues. Infections with the larval stages such as VLM, eosinophylic meningitis, occult filanasis and other could only be suspected, since the diagnosis was extremely difficult and based on the finding and identification of the parasite. Many cases of creeping eruption which might be caused by the larval stages of A.caninum and A.braziliense and Strongyloides stercoralis

  11. IMPORTANT NEMATODE INFECTIONS IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Sri Oemijati

    2012-09-01

    Full Text Available At least 13 species of intestinal nematodes and 4 species of blood and tissue nematodes have been reported infecting man in Indonesia. Five species of intestinal nematodes are very common and highly prevalent, especially in the rural areas and slums of the big cities. Those species are Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Trichuris trichiura and Oxyuris vermicularis, while Strongyloides stercoralis is disappearing. The prevalence of the soil transmitted helminths differs from place to place, depending on many factors such as the type of soil, human behaviour etc. Three species of lymph dwelling filarial worms are known to be endemic, the urban Wuchereria bancrofti is low endemic in Jakarta and a few other cities along the north coast of Java, with Culex incriminated as vector, high endemicity is found in Irian Jaya, where Anopheline mosquitoes act as vectors. Brugia malayi is widely distributed and is still highly endemic in many areas. The zoonotic type is mainly endemic in swampy areas, and has many species of Mansonia mosquitoes as vectors. B.timori so far has been found only in the south eastern part of the archipelago and has Anopheles barbirostris as vector. Human infections with animal parasites have been diagnosed properly only when adult stages were found either in autopsies or removed tissues. Cases of infections with A. caninum, A.braziliense, A.ceylanicum, Trichostrongylus colubriformis, T.axei and Oesophagostomum apiostomum have been desribed from autopsies, while infections with Gnathostoma spiningerum have been reported from removed tissues. Infections with the larval stages such as VLM, eosinophylic meningitis, occult filanasis and other could only be suspected, since the diagnosis was extremely difficult and based on the finding and identification of the parasite. Many cases of creeping eruption which might be caused by the larval stages of A.caninum and A.braziliense and Strongyloides stercoralis

  12. RNA interference in plant parasitic nematodes

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... produce effective and durable forms of nematode control. Principle advantages ... Carthew, 1998, 2000) and amphibians (Dirks et al., 2003;. Li and Rohrer .... glands. Cysteine proteinase. Increased male: female ratio. Intestine.

  13. Parasitic Nematode Interactions with Mammals and Plants

    NARCIS (Netherlands)

    Jasmer, D.P.; Goverse, A.; Smant, G.

    2003-01-01

    Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent

  14. Conserving and enhancing biological control of nematodes.

    Science.gov (United States)

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  15. Improved Nematode Extraction from Carrot Disk Culture

    OpenAIRE

    Kaplan, David T.; Davis, Eric L.

    1990-01-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solut...

  16. Ascaroside Signaling is Widely Conserved Among Nematodes

    OpenAIRE

    Choe, Andrea; von Reuss, Stephan H.; Kogan, Dima; Robin B Gasser; Platzer, Edward G.; Schroeder, Frank C.; Paul W. Sternberg

    2012-01-01

    Background: Nematodes are among the most successful animals on earth and include important human pathogens, yet little is known about nematode pheromone systems. A group of small molecules called ascarosides has been found to mediate mate finding, aggregation, and developmental diapause in Caenorhabditis elegans, but it is unknown whether ascaroside signaling exists outside of the genus Caenorhabditis. Results: To determine whether ascarosides are used as signaling molecules by other nemat...

  17. Field level risk assessment for root-knot nematodes in lima beans

    Science.gov (United States)

    Southern Root-Knot Nematode (RKN), Meloidogyne incognita, is a major yield limiting pest in lima beans (Phaseolus lunatus). RKN are not evenly distributed through fields and population dynamics are fluid making whole field management challenging. The objectives of this research were to characterize ...

  18. The role of root architecture in foraging behavior of entomopathogenic nematodes

    Science.gov (United States)

    1. As obligate parasites, entomopathogenic nematodes (EPN) rely on insect hosts to complete their development. In insect pest management, EPN infectiousness has varied a lot. A better understanding of their host-finding behavior in the rhizosphere is therefore crucial to enhance EPN potential in bio...

  19. Nematode beta diversity on the continental slope of New Zealand: spatial patterns and environmental drivers

    NARCIS (Netherlands)

    Leduc, D.; Rowden, A.A.; Bowden, D.A.; Nodder, S.D.; Probert, P.K.; Pilditch, C.A.; Duineveld, G.C.A.; Witbaard, R.

    2012-01-01

    The management of marine biodiversity relies on sound knowledge of beta (or turnover) and gamma (or regional) diversity patterns, but such knowledge is largely lacking for continental slope environments. Here, we used free-living nematodes to investigate spatial and environmental patterns of beta an

  20. Bibliography of U.S. Extension and Extension-related Publications on Nematodes.

    Science.gov (United States)

    1988-10-01

    A listing was compiled of hematology publications available through the Cooperative Extension Service and similar organizations in the United States. It provides a convenient reference to current articles addressing many of the more applied aspects of plant nematology and nematode management.

  1. Evaluation of Variable Rate Application of Nematicides in Cotton According to Nematode Risk Zones

    Science.gov (United States)

    Cotton (Gossypium hirsutum L.) lint yield losses by southern root-knot nematode [Meloidogyne incognita] (RKN) have increased during the last 20 years. Site-specific management (SSM) of nematicides is a promising method to reduce yield losses, increase profitability and reduce adverse environmental i...

  2. Fungi associated with free-living soil nematodes in Turkey

    Directory of Open Access Journals (Sweden)

    Karabörklü Salih

    2015-01-01

    Full Text Available Free-living soil nematodes have successfully adapted world-wide to nearly all soil types from the highest to the lowest of elevations. In the current study, nematodes were isolated from soil samples and fungi associated with these free-living soil nematodes were determined. Large subunit (LSU rDNAs of nematode-associated fungi were amplified and sequenced to construct phylogenetic trees. Nematode-associated fungi were observed in six nematode strains belonging to Acrobeloides, Steinernema and Cephalobus genera in different habitats. Malassezia and Cladosporium fungal strains indicated an association with Acrobeloides and Cephalobus nematodes, while Alternaria strains demonstrated an association with the Steinernema strain. Interactions between fungi and free-living nematodes in soil are discussed. We suggest that nematodes act as vectors for fungi.

  3. Phytoalexin Phenalenone Derivatives Inactivate Mosquito Larvae and Root-knot Nematode as Type-II Photosensitizer

    Science.gov (United States)

    Song, Runjiang; Feng, Yian; Wang, Donghui; Xu, Zhiping; Li, Zhong; Shao, Xusheng

    2017-02-01

    Phytoalexins phenalenones (PNs) are phytochemicals biosynthesized inside the plant in responsive to exterior threat. PNs are excellent type-II photosensitizers, which efficiently produce singlet oxygen upon light irradiation. Based on the core functional structure of PNs, novel PN derivatives were synthesized here and their singlet oxygen generating abilities and their phototoxicity were evaluated. At the presence of light, these PNs have photoinduced toxicity towards Aedes albopictus larvae and nematode Meloidogyne incognita, while the activity lost in the dark. The obvious tissue damage was observed on the treated mosquito larvae and nematode due to the generation of singlet oxygen. Our results revealed the potential of phenalenones as photoactivated agents for mosquito and root-knot nematode management together with light.

  4. Molecular mechanisms of nematode-nematophagous microbe interactions: basis for biological control of plant-parasitic nematodes.

    Science.gov (United States)

    Li, Juan; Zou, Chenggang; Xu, Jianping; Ji, Xinglai; Niu, Xuemei; Yang, Jinkui; Huang, Xiaowei; Zhang, Ke-Qin

    2015-01-01

    Plant-parasitic nematodes cause significant damage to a broad range of vegetables and agricultural crops throughout the world. As the natural enemies of nematodes, nematophagous microorganisms offer a promising approach to control the nematode pests. Some of these microorganisms produce traps to capture and kill the worms from the outside. Others act as internal parasites to produce toxins and virulence factors to kill the nematodes from within. Understanding the molecular basis of microbe-nematode interactions provides crucial insights for developing effective biological control agents against plant-parasitic nematodes. Here, we review recent advances in our understanding of the interactions between nematodes and nematophagous microorganisms, with a focus on the molecular mechanisms by which nematophagous microorganisms infect nematodes and on the nematode defense against pathogenic attacks. We conclude by discussing several key areas for future research and development, including potential approaches to apply our recent understandings to develop effective biocontrol strategies.

  5. Influence of Metalaxyl on Three Nematodes of Citrus

    Science.gov (United States)

    Kaplan, David T.

    1983-01-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant. PMID:19295833

  6. Estrutura da população de nematoides do solo em uma unidade de produção agroecológica no Estado do Rio de Janeiro, Brasil = Structure of soil nematode population under an organically managed crop in Rio de Janeiro State, Brazil.

    Directory of Open Access Journals (Sweden)

    Adriana França Figueira

    2011-04-01

    bacterivores and herbivore nematodes was high in all areas. Omnivores were found in lower abundance in all systems. The highest diversity of nematode families was found on pasture. In forests, the values of richness and abundance were always lower but constant in time, suggesting an ecosystem of higher stability. Soil management induced the proliferation of bacterivores usually associated with higher decomposition rates of organic matter. Herbivores and bacterivores were dominant in all systems, suggesting it is important to have high root (for pasture or high decomposition rates (for horticulture system. The relative distribution of trophic groups of soil nematodes proved to be a good way to determine the level of perturbation of ecosystems.

  7. Interspecific nematode signals regulate dispersal behavior.

    Directory of Open Access Journals (Sweden)

    Fatma Kaplan

    Full Text Available BACKGROUND: Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2 of plant parasitic Meloidogyne spp. and infective juveniles (IJs of entomopathogenic nematodes (EPN, e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. METHODOLOGY/PRINCIPAL FINDINGS: Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9. A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9 and C. elegans (ascr#2 dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. CONCLUSIONS/SIGNIFICANCE: Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.

  8. Two new species of soil nematodes from Manipur, India.

    Science.gov (United States)

    Chanu, Loukrakpam Bina; Meitei, N Mohilal; Shah, M Manjur

    2016-09-01

    Survey for soil nematodes associated with mulberry plants in valley districts of Manipur revealed the presence of two new species of soil nematodes of the genus Tylenchus sp. and Telotylenchus sp. The two new species are described and illustrated here.

  9. Chip Technologies for Screening Chemical and Biological Agents Against Plant-Parasitic Nematodes.

    Science.gov (United States)

    Beeman, Augustine Q; Njus, Zach L; Pandey, Santosh; Tylka, Gregory L

    2016-12-01

    Plant-parasitic nematodes cause substantial damage to agricultural crops worldwide. Long-term management of these pests requires novel strategies to reduce infection of host plants. Disruption of nematode chemotaxis to root systems has been proposed as a potential management approach, and novel assays are needed to test the chemotactic behavior of nematodes against a wide range of synthetic chemicals and root exudates. Two microfluidic chips were developed that measure the attraction or repulsion of nematodes to chemicals ("chemical chip") and young plant roots ("root chip"). The chip designs allowed for chemical concentration gradients to be maintained up to 24 h, the nematodes to remain physically separate from the chemical reservoirs, and for images of nematode populations to be captured using either a microscope or a flatbed scanner. In the experiments using the chemical chips, seven ionic solutions were tested on second-stage juveniles (J2s) of Meloidogyne incognita and Heterodera glycines. Results were consistent with previous reports of repellency of M. incognita to a majority of the ionic solutions, including NH4NO3, KNO3, KCl, MgCl2, and CaCl2. H. glycines was found to be attracted to both NH4NO3 and KNO3, which has not been reported previously. A software program was written to aid in monitoring the location of nematodes at regular time intervals using the root chip. In experiments with the root chip, H. glycines J2s were attracted to roots of 3-day-old, susceptible (cultivar Williams 82) soybean seedlings, and attraction of H. glycines to susceptible soybean was similar across the length of the root. Attraction to resistant (cultivar Jack) soybean seedlings relative to the water only control was inconsistent across runs, and H. glycines J2s were not preferentially attracted to the roots of resistant or susceptible cultivars when both were placed on opposite sides of the same root chip. The chips developed allow for direct tests of plant

  10. Nematode feeding sites: unique organs in plant roots.

    Science.gov (United States)

    Kyndt, Tina; Vieira, Paulo; Gheysen, Godelieve; de Almeida-Engler, Janice

    2013-11-01

    Although generally unnoticed, nearly all crop plants have one or more species of nematodes that feed on their roots, frequently causing tremendous yield losses. The group of sedentary nematodes, which are among the most damaging plant-parasitic nematodes, cause the formation of special organs called nematode feeding sites (NFS) in the root tissue. In this review we discuss key metabolic and cellular changes correlated with NFS development, and similarities and discrepancies between different types of NFS are highlighted.

  11. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    DEFF Research Database (Denmark)

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  12. [Research Progress on Genetic Diversity in Animal Parasitic Nematodes].

    Science.gov (United States)

    YIN, Fang-yuan; LI, Fa-cai; ZHAO, Jun-long; HU, Min

    2015-10-01

    The development of molecular genetic markers for parasitic nematodes has significant implications in fundamental and applied research in Veterinary Parasitology. Knowledge on genetic diversity of nematodes would not only provide a theoretical basis for understanding the spread of drug-resistance alleles, but also have implications in the development of nematode control strategies. This review discusses the applications of molecular genetic markers (RFLP, RAPD, PCR-SSCP, AFLP, SSR and mitochondrial DNA) in research on the genetic diversity of parasitic nematodes.

  13. Use of the arbuscular mycorrhizal fungus Glomus intraradices as biological control agent of the nematode Nacobbus aberrans parasitizing tomato

    Directory of Open Access Journals (Sweden)

    Nicolás Marro

    2014-10-01

    Full Text Available The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of "races/groups" with different behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF. In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population of N. aberrans. AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting.

  14. Inducing effect of PGRs on small regulatory si/miRNA in resistance to sugar beet cyst nematode.

    Science.gov (United States)

    Tsygankova, V A; Stefanovska, T R; Galkin, A P; Ponomarenko, S P; Blume, Ya B

    2012-01-01

    Sugar beet cyst nematode Heterodera schachtii Schmidt is an economically important plant parasite of sugar beet in Ukraine. The pest control options are limited. Sugar beet cyst nematode resistant varieties are not available on the market. Carbamate and organophosphate pesticides have been banned due to the high toxicity. The problem is aggravated by continuously increasing of oilseed rape (which is suitable host for H. schachtii) growing area due to biofuel demands. Several studies' results indicate that PGRs have role in management of plant parasitic nematodes but for sugar beet it is not studied well. We had an objective- studying of the role of four compositional PGRs created based of avermectin in suppression of sugar beet cyst nematode population on sugar beet and oilseed rape caused by enhancing of endogenous si/miRNA complementary to H. schachtii mRNA. Laboratory study was conducted in 2011 with using method DOT-blot hybridization si/miRNA with mRNA and by testing inhibitory activity in cell free system protein biosynthesis. That was shown that application of the PGRs enhances sugar beet and oilseeds rape plant immune-protective properties and resistance against plant-parasitic nematode Heterodera schochtii through enhancement of synthesis of small regulatory si/miRNA related (complementary) to an mRNA structure of the parasitic organisms. As a result, translation of mRNA of the nematode is blocked and causes the mortality of plant parasite juveniles.

  15. Characterization of biocontrol traits in the entomopathogenic nematode Heterorhabditis georgiana (Kesah strain), and phylogenetic analysis of the nematode's symbiotic bacteria.

    Science.gov (United States)

    Our objective was to estimate the biocontrol potential of the recently discovered entomopathogenic nematode species, Heterorhabditis georgiana (Kesha strain). Virulence and environmental tolerance were tested among several nematode species. Heterorhabditis georgiana expressed low or intermediate c...

  16. Managing diseases in seed garlic: What are the options?

    Science.gov (United States)

    Organisms (fungi, bacteria, viruses and nematodes) causing diseases of seed garlic are discussed in terms of their pathogenic abilities, aggressiveness, management constraints and management options. Management options for vectors (for viral diseases) are placed in context. Concise and general manag...

  17. Microbial ecology and nematode control in natural ecosystems

    NARCIS (Netherlands)

    Costa, S.R.; Van der Putten, W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient cyclin

  18. Cyst nematode-induced changes in plant development

    NARCIS (Netherlands)

    Goverse, A.

    1999-01-01

    This thesis describes a first attempt to investigate the biological activity of cyst nematode secretions on plant cell proliferation and the molecular mechanisms underlying feeding cell development in plant roots upon cyst nematode infection.To investigate the role of nematode secretions in feeding

  19. A novel flavivirus in the soybean cyst nematode

    Science.gov (United States)

    Heterodera glycines, the soybean cyst nematode (SCN) is a subterranean root pathogen that causes the most damaging disease of soybean in the United States. A novel nematode virus genome, soybean cyst nematode virus 5 (SbCNV5), was identified in RNASeq data from SCN eggs and second-stage juveniles. T...

  20. Microbial ecology and nematode control in natural ecosystems

    NARCIS (Netherlands)

    Costa, S.R.; Van der Putten, W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient

  1. ENDOPARASITIC NEMATODES OF THE GENUS PRATYLENCHUS ON SOYBEAN

    OpenAIRE

    Ivana Majić

    2010-01-01

    The aims of the study were to determine susceptibility of soybean cultivars to root lesion nematodes (genus Pratylenchus), effect of intensity of arbuscular mycorrhizal fungi (AMF) colonization on penetration of endoparasitic nematodes in soybean roots, and trophic biodiversity of nematode community in soybean. In the period 2005 - 2007, investigations were conducted at experimental sites of Agricultural Institute Osijek. Seven soybean cultivars were included (Korana, ...

  2. Nematode problems affecting agriculture in the Philippines.

    Science.gov (United States)

    Davide, R G

    1988-04-01

    Nematodes are considered major pests on most economic crops in the Philippines, particularly on banana, pineapple, citrus, tomato, ramie, and sugarcane. Radopholus similis is the most destructive nematode on banana, while Meloidogyne spp. are more serious on various vegetable crops such as tomato, okra, and celery and on fiber crops such as ramie. Tylenchulus semipenetrans is a problem on citrus and Rotylenchulus reniformis on pineapple and some legume crops. Hirschmanniella oryzae and Aphelenchoides besseyi are becoming serious on rice, and Pratylenchus zeae is affecting corn in some areas. Lately, Globodera rostochiensis has been causing serious damage on potato in the highlands. Control measures such as crop rotation, planting resistant varieties, chemical nematicide application, and biological control have been recommended to control these nematodes.

  3. Nematode taxonomy: from morphology to metabarcoding

    Science.gov (United States)

    Ahmed, M.; Sapp, M.; Prior, T.; Karssen, G.; Back, M.

    2015-11-01

    Nematodes represent a species rich and morphologically diverse group of metazoans inhabiting both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some groups of nematodes are also known to cause significant losses to crop production. In spite of this, knowledge of their diversity is still limited due to the difficulty in achieving species identification using morphological characters. Molecular methodology has provided very useful means of circumventing the numerous limitations associated with classical morphology based identification. We discuss herein the history and the progress made within the field of nematode systematics, the limitations of classical taxonomy and how the advent of high throughput sequencing is facilitating advanced ecological and molecular studies.

  4. ENDOPARASITIC NEMATODES OF THE GENUS PRATYLENCHUS ON SOYBEAN

    Directory of Open Access Journals (Sweden)

    Ivana Majić

    2010-12-01

    Full Text Available The aims of the study were to determine susceptibility of soybean cultivars to root lesion nematodes (genus Pratylenchus, effect of intensity of arbuscular mycorrhizal fungi (AMF colonization on penetration of endoparasitic nematodes in soybean roots, and trophic biodiversity of nematode community in soybean. In the period 2005 - 2007, investigations were conducted at experimental sites of Agricultural Institute Osijek. Seven soybean cultivars were included (Korana, Kuna, Anica, Una, Ika, Podravka 95 i Tisa. Soil and roots were sampled during four soybean growth stages. Nematode populations from soil and root samples were determined as well as reproductive index (RI of root lesion nematode population, and intensity of AMF root colonization. Ten ecological indexes were calculated in order to determine trophic biodiversity of nematode community: H’, λ, N1, N2, E1, E2, PPI, NCR, F/B, B+F/BP. Two Pratylenchus species were determined from the soil samples: P. thornei Sher & Allen 1953 and P. scribneri Steiner 1943. The results indicate negative effect of Pratylenchus spp. (extracted from soil samples on soybean yields for all but one cultivar (Una. However, increase in root lesion nematode population did not lead to linear decrease in plant biomass. Cultivars Ika, Podravka 95, Tisa and Una proved to be the best hosts to root lesion nematodes since these cultivars statistically differed among cultivars for the highest density of root lesion nematodes. Cultivar Una showed the least susceptibility to root lesion nematodes since it had the lowest RI and negative effects on yields were not determined. Due to high RI values and negative effect on soybean yields. Population densities of root lesion nematodes from soil samples, (compared to nematodes detected in roots are more reliable indicator of root lesion nematodes damaging potential. Since values of RI for Pratylenchus spp. in soil samples were determined as very high and soybean yields were

  5. [Nematode parasites of birds of the fauna in Tunisia].

    Science.gov (United States)

    Bernard, J

    1989-01-01

    330 birds of Tunisia were necropsied; they belong to 73 species among 29 families and 13 orders. We so collect 36 species of nematodes from 9 families. The relative importance of these is variable. The best represented are: Capillariidae (6 species), Spiruridae (6 species), Acuariidae (9 species) and Filariidae (6 species). The parasitism by nematodes is not uniform. Among the 330 birds autopsied only 51 were parasited by nematodes (15.45%) among 25 of the examined birds species (34.2%). Among these 25, sixteen (64%) presented only one species of parasitic nematode, six (24%) arboured two, (8%) three and only one, (partridges) presents six species of nematodes.

  6. Tropical rotation crops influence nematode densities and vegetable yields.

    Science.gov (United States)

    McSorley, R; Dickson, D W; de Brito, J A; Hochmuth, R C

    1994-09-01

    The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, American jointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops.

  7. A survey of nematodes of the genus Cucullanus Müller, 1777 (Nematoda, Seuratoidea) parasitic in marine fishes off Brazil, including description of three new species.

    Science.gov (United States)

    Vieira, Fabiano M; Pereira, Felipe B; Pantoja, Camila; Soares, Iris A; Pereira, Aldenice N; Timi, Juan T; Scholz, Tomáš; Luque, José L

    2015-11-05

    A taxonomic survey of six nematode species (including three new taxa) from the genus Cucullanus Müller, 1777, parasites of marine fishes off the Brazilian coast, is provided. Nematodes were studied using light and scanning electron microscopy (SEM). Cucullanus gastrophysi n. sp. parasitic in Lophius gastrophysus Miranda Ribeiro differs from its congeners by the combination of the following features: shape and number of sclerotized structures in the oesophastome (a pair of lateral elongate structures and a single small reniform one), position of deirids and excretory pore (both anterior to oesophagus base), spicule length and spicule/body length ratio (0.97-1.29 mm and 6.5-10.5%, respectively), morphology and length of gubernaculum (V-shaped, 107-135 µm long). Cucullanus protrudens n. sp. from Pagrus pagrus (Linnaeus) has the cloacal lips broadly protruded, which differentiates it from several species of Cucullanus; other features, e.g., the length of spicules and gubernaculum (400-415 µm and 91-103 µm, respectively), arrangement of caudal papillae and position of excretory pore (slightly posterior to oesophagus-intestine junction) also characterize this species. Cucullanus pseudopercis n. sp. from Pseudopercis semifasciata (Cuvier) has deirids and excretory pore posterior to the oesophagus-intestine junction, which distinguishes the species from most of the congeners; furthermore, the arrangement of caudal papillae in combination with the length of spicules and gubernaculum (1.0-1.5 mm and 178-196 µm, respectively) separate this species from other taxa. Newly collected specimens of C. cirratus Müller, 1777 (type species of the genus) from Urophycis brasiliensis (Kaup), C. pedroi from Conger orbignianus Valenciennes (type host of the species) and C. genypteri Sardella, Navone & Timi, 1997 from Genypterus brasiliensis Regan, were studied as well. Comparisons between newly collected samples and the taxonomic data available for each respective species revealed

  8. Essential oils as anti-nematode agents and their influence on in vitro nematode

    OpenAIRE

    Faria, Jorge Miguel Silva, 1983-

    2015-01-01

    Tese de doutoramento, Biologia (Biotecnologia), Universidade de Lisboa, Faculdade de Ciências, 2015 Parasitic nematodes are among the most production-limiting plant pests. In Europe, the recent introduction of Bursaphelenchus xylophilus [the pinewood nematode (PWN)] and some species of Meloidogyne has proved damaging to forest ecosystems and crop production. Due to the very laborious and environment-dependent nature of greenhouse or field assays, in vitro host with parasite co-cultures can...

  9. Cuticle surface coat of plant-parasitic nematodes.

    Science.gov (United States)

    Davies, Keith G; Curtis, Rosane H C

    2011-01-01

    The surface coat (SC) of the plant-parasitic nematode cuticle is an understudied area of current research, even though it likely plays key roles in both nematode-plant and nematode-microbe interactions. Although in several ways Caenorhabditis elegans is a poor model for plant-parasitic nematodes, it is a useful starting point for investigations of the cuticle and its SC, especially in the light of recent work using this species as a model for innate immunity and the generic biology underpinning much host-parasite biology. We review the research focused on the involvement of the SC of plant-parasitic nematodes. Using the insights gained from animal-parasitic nematodes and other sequenced nematodes, we discuss the key roles that the SC may play. Copyright © 2011 by Annual Reviews. All rights reserved.

  10. Cryopreservation of roe deer abomasal nematodes for morphological identification.

    Science.gov (United States)

    Beraldo, Paola; Pascotto, Ernesto

    2014-02-01

    Conventional methods to preserve adult nematodes for taxonomic purposes involve the use of fixative or clearing solutions (alcohol, formaldehyde, AFA and lactophenol), which cause morphological alterations and are toxic. The aim of this study is to propose an alternative method based on glycerol-cryopreservation of nematodes for their subsequent identification. Adults of trichostrongylid nematodes from the abomasum of roe deer (Capreolus capreolus Linnaeus) were glycerol-cryopreserved and compared with those fixed in formaldehyde, fresh and frozen without cryoprotectans. Morphology, transparency and elasticity of the anterior and posterior portion of male nematodes were compared, especially the caudal cuticular bursa and genital accessories. The method presented is quick and easy to use, and the quality of nematode specimens is better than that of nematodes fixed by previously used fixatives. Moreover, glycerol cryopreserved nematodes can be stored for a long time at -20 degrees C in perfect condition and they could be suitable for further analyses, such as histological or ultrastructural examinations.

  11. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific

  12. Nutritional requirements for soybean cyst nematode

    Science.gov (United States)

    Soybeans [Glycine max] are the second largest cash crop in US Agriculture, but the soybean yield is compromised by infections from Heterodera glycines, also known as Soybean Cyst Nematodes [SCN]. SCN are the most devastating pathogen or plant disease soybean producers confront. This obligate parasi...

  13. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific plan

  14. Mermithid Nematodes: In Vitro Culture Attempts

    OpenAIRE

    Finney, Jean R.

    1981-01-01

    Few attempts at in vitro culture of mermithids have been undertaken. The various methods used to initiate cultures are described. The capacity of a range of media to promote growth and development of the nematodes has been evaluated and current approaches to in vitro outlined.

  15. Focus on molecular plant-nematode interactions

    NARCIS (Netherlands)

    Hogenhout, S.; Mitchum, M.; Smant, G.

    2013-01-01

    Sedentary plant-parasitic nematodes engage in a long-lasting and intimate relationship with their host plant. This interaction starts in the soil when freshly hatched infective juveniles are attracted to specific parts of a host plant root system. Little is known of what determines the attractivenes

  16. Nematodes: Model Organisms in High School Biology

    Science.gov (United States)

    Bliss, TJ; Anderson, Margery; Dillman, Adler; Yourick, Debra; Jett, Marti; Adams, Byron J.; Russell, RevaBeth

    2007-01-01

    In a collaborative effort between university researchers and high school science teachers, an inquiry-based laboratory module was designed using two species of insecticidal nematodes to help students apply scientific inquiry and elements of thoughtful experimental design. The learning experience and model are described in this article. (Contains 4…

  17. Potato cyst nematodes: pests of national importance

    Science.gov (United States)

    Potato cyst nematodes (PCN; G. rostochiensis and G. pallida) are internationally-recognized quarantine pests and considered the most devastating pests of potatoes due to annual worldwide yield losses estimated at 12.2%. PCNs continue to spread throughout North America and were recently detected in I...

  18. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival

  19. Diverse CLE peptides from cyst nematode species

    Science.gov (United States)

    Plant CLAVATA3/ESR (CLE)-like peptides play diverse roles in plant growth and development including maintenance of the stem cell population in the root meristem. Small secreted peptides sharing similarity to plant CLE signaling peptides have been isolated from several cyst nematode species including...

  20. Evolution of embryonic development in nematodes

    Directory of Open Access Journals (Sweden)

    Schulze Jens

    2011-09-01

    Full Text Available Abstract Background Nematodes can be subdivided into basal Enoplea (clades 1 and 2 and more derived Chromadorea (clades 3 to 12. Embryogenesis of Caenorhabditis elegans (clade 9 has been analyzed in most detail. Their establishment of polarity and asymmetric cleavage requires the differential localization of PAR proteins. Earlier studies on selected other nematodes revealed that embryonic development of nematodes is more diverse than the essentially invariant development of C. elegans and the classic study object Ascaris had suggested. To obtain a more detailed picture of variations and evolutionary trends we compared embryonic cell lineages and pattern formation in embryos of all 12 nematode clades. Methods The study was conducted using 4-D microscopy and 3-D modeling of developing embryos. Results We found dramatic differences compared to C. elegans in Enoplea but also considerable variations among Chromadorea. We discovered 'Polarity Organizing Centers' (POCs that orient cleavage spindles along the anterior-posterior axis in distinct cells over consecutive cell generations. The resulting lineally arranged blastomeres represent a starting point for the establishment of bilateral symmetry within individual lineages. We can discern six different early cleavage types and suggest that these variations are due to modifications in the activity of the POCs in conjunction with changes in the distribution of PAR proteins. In addition, our studies indicate that lineage complexity advanced considerably during evolution, that is we observe trends towards an increase of somatic founder cells, from monoclonal to polyclonal lineages and from a variable (position-dependent to an invariable (lineage-dependent way of cell fate specification. In contrast to the early phase of embryogenesis, the second half ('morphogenesis' appears similar in all studied nematodes. Comparison of early cleavage between the basal nematode Tobrilus stefanskii and the tardigrade

  1. The integrated use of chemical insecticides and the entomopathogenic nematode, Steinernema carpocapsae(Nematoda: Steinernematidae), for the control of sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    Andrew G. S. Cuthbertson; James J. Mathers; Phil Northing; Anthony J. Prickett; Keith F. A. Waiters

    2008-01-01

    The integration of chemical insecticides and infective juveniles of the entomopathogenic nematode Steinernema carpocapsae (Wesier) (Nematoda:Steinernematidae), to control second instars of the sweetpotato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) was investigated. Using a sand bioassay, the effects of direct exposure of S. carpocapsae for 24 h to field rate dilutions of four insecticides (spiromesifen, thiacloprid, imidaeloprid and pymetrozine) on infectivity to Galleria rnellonella larvae were tested. Although all chemicals tested, except spiromesifen, produced acceptable nematode infectivity rates, they were all significantly less than the water control. The effect of insecticide treatment (dry residues of spiromesifen, thiacloprid and pymetrozine and soil drench of imidacloprid) on the efficacy of the nematode against B. tabaci was also investigated. Nematodes in combination with thiacloprid and spiromesifen gave higher B.tabaci mortality (86.5% and 94.3% respectively) compared to using nematodes alone (75.2%) on tomato plants. There was no significant difference in B. tabaci mortality when using the chemicals imidacloprid, pymetrozine and spiromesifen in conjunction with nematodes compared to using the chemicals alone. However, using thiaeloprid in combination with the nematodes produced significantly higher B. tabaci mortality than using the chemical alone. The integration of S. carpocapsae and these chemical agents into current integrated pest management programmes for the control of B. tabaci is discussed.

  2. Prevalence of anthelmintic resistance in gastrointestinal nematodes of sheep and goats in Norway.

    Science.gov (United States)

    Domke, Atle V Meling; Chartier, Christophe; Gjerde, Bjørn; Höglund, Johan; Leine, Nils; Vatn, Synnøve; Stuen, Snorre

    2012-07-01

    In the period of 2008–2009, the efficacies of the benzimidazole (BZ) albendazole and the macrocyclic lactone (ML) ivermectin against gastrointestinal nematodes (GIN) of small ruminants were evaluated by means of the fecal egg count reduction (FECR) test and by post-treatment identification of surviving third stage (L3) larvae after coproculture. Sheep (n=28) and goat (n=28) flocks from three areas of Norway were randomly selected to assess the prevalence of anthelmintic resistance (AR), whereas only lambs from non-randomly selected sheep flocks (n=32) with a farm management that could select for AR were investigated the second year. Only flocks with a mean excretion of nematode eggs per gram feces (EPG) ≥ 150 at time of treatment were included in the survey. In total, 48 (80%) and 13 (46.4%) of the selected sheep and goat flocks, respectively, fulfilled the inclusion criteria. The proportions of flocks classified as resistant (i.e., FECR nematode genera were Teladorsagia/Trichostrongylus in five flocks, Haemonchus in two flocks, and a mixture of these genera in the remaining two flocks. In the goat flocks, the pre-treatment infection levels of GIN were low compared to what was found in the sheep flocks. Still, in one flock, AR against BZ in Teladorsagia/Trichostrongylus was found. New strategies and recommendations to face the emerging AR situation in Rogaland County in order to limit the spread of resistant nematodes within and into other areas are urgently needed.

  3. Study on the Sustainable Management of Pine Wood Nematode (Bursaphelenchus xylophilis) in Old Epidemic Areas%老疫区松材线虫病持续控制技术研究

    Institute of Scientific and Technical Information of China (English)

    范军祥; 黄焕华; 钱明惠; 黄咏槐; 武海卫

    2011-01-01

    2005~2009年在广州市松材线虫病老疫区系统开展了疑似病死松树的早期诊断、应用引诱剂和林间释放花绒寄甲控制松褐天牛、清理病死木套袋熏蒸和疫区松林植物群落结构改造等持续控制技术研究.结果表明:疫区内松树枯死木松材线虫的检出率为22.1%~55.4%.诱到松褐天牛成虫19 853头,每个诱捕器的诱虫量为14.06~24.80头/年.释放花绒寄甲成虫1 115头,寄生率为9.21%~60.00%.清理枯死木14 769株,熏蒸袋内的松褐天牛死亡率达到99.5%以上.在松林内套种39种阔叶树共112 000株,改善了松林的植物群落结构,提高了松林对松褐天牛及松材线虫病的抗性.%The sustainable control technology research on pine wood nematode ( Bursaphelenchus xylophilis)and pine sawyer beetle ( Monochamus alternatus) have been carried out in Guangzhou old epidemic areas from 2005 to 2009. The main technical measures including ( 1 ) Early diagnosis of pine wilt disease; (2) Control and monitor the adults M. alternatus by attractant; (3) Control pine sawyer beetles by releasing Dastarcus helophoroides; (4)Clean up dead trees and extinguish pests in woodlands; (5) Modification on the plant community structure in pine forest. The results showed that the detection rate of B. xylophilis from dead trees is 22.1% ~55.4%; 19 583 adults of M. alternatus have been trap in the test area, and 14.06 ~24.80 adults per trap set in a year; 1 115 D.helophoroides were released in the pine forest, and the parasitism rate is 9.21% ~ 60.00%; 14 769 dead trees have been clean up, the mortality rate of M. alternatus larva or pupae is up to 99.5%; 112 000 broadleaf trees (39 species) were planted in the pine forests, the plant community gets higher resistance to pine sawyer and pine wood nematode disease.

  4. Parasitic Nematode Immunomodulatory Strategies: Recent Advances and Perspectives.

    Science.gov (United States)

    Cooper, Dustin; Eleftherianos, Ioannis

    2016-09-14

    More than half of the described species of the phylum Nematoda are considered parasitic, making them one of the most successful groups of parasites. Nematodes are capable of inhabiting a wide variety of niches. A vast array of vertebrate animals, insects, and plants are all identified as potential hosts for nematode parasitization. To invade these hosts successfully, parasitic nematodes must be able to protect themselves from the efficiency and potency of the host immune system. Innate immunity comprises the first wave of the host immune response, and in vertebrate animals it leads to the induction of the adaptive immune response. Nematodes have evolved elegant strategies that allow them to evade, suppress, or modulate host immune responses in order to persist and spread in the host. Nematode immunomodulation involves the secretion of molecules that are capable of suppressing various aspects of the host immune response in order to promote nematode invasion. Immunomodulatory mechanisms can be identified in parasitic nematodes infecting insects, plants, and mammals and vary greatly in the specific tactics by which the parasites modify the host immune response. Nematode-derived immunomodulatory effects have also been shown to affect, negatively or positively, the outcome of some concurrent diseases suffered by the host. Understanding nematode immunomodulatory actions will potentially reveal novel targets that will in turn lead to the development of effective means for the control of destructive nematode parasites.

  5. Parasitic Nematode Immunomodulatory Strategies: Recent Advances and Perspectives

    Science.gov (United States)

    Cooper, Dustin; Eleftherianos, Ioannis

    2016-01-01

    More than half of the described species of the phylum Nematoda are considered parasitic, making them one of the most successful groups of parasites. Nematodes are capable of inhabiting a wide variety of niches. A vast array of vertebrate animals, insects, and plants are all identified as potential hosts for nematode parasitization. To invade these hosts successfully, parasitic nematodes must be able to protect themselves from the efficiency and potency of the host immune system. Innate immunity comprises the first wave of the host immune response, and in vertebrate animals it leads to the induction of the adaptive immune response. Nematodes have evolved elegant strategies that allow them to evade, suppress, or modulate host immune responses in order to persist and spread in the host. Nematode immunomodulation involves the secretion of molecules that are capable of suppressing various aspects of the host immune response in order to promote nematode invasion. Immunomodulatory mechanisms can be identified in parasitic nematodes infecting insects, plants, and mammals and vary greatly in the specific tactics by which the parasites modify the host immune response. Nematode-derived immunomodulatory effects have also been shown to affect, negatively or positively, the outcome of some concurrent diseases suffered by the host. Understanding nematode immunomodulatory actions will potentially reveal novel targets that will in turn lead to the development of effective means for the control of destructive nematode parasites. PMID:27649248

  6. Parasitic Nematode Immunomodulatory Strategies: Recent Advances and Perspectives

    Directory of Open Access Journals (Sweden)

    Dustin Cooper

    2016-09-01

    Full Text Available More than half of the described species of the phylum Nematoda are considered parasitic, making them one of the most successful groups of parasites. Nematodes are capable of inhabiting a wide variety of niches. A vast array of vertebrate animals, insects, and plants are all identified as potential hosts for nematode parasitization. To invade these hosts successfully, parasitic nematodes must be able to protect themselves from the efficiency and potency of the host immune system. Innate immunity comprises the first wave of the host immune response, and in vertebrate animals it leads to the induction of the adaptive immune response. Nematodes have evolved elegant strategies that allow them to evade, suppress, or modulate host immune responses in order to persist and spread in the host. Nematode immunomodulation involves the secretion of molecules that are capable of suppressing various aspects of the host immune response in order to promote nematode invasion. Immunomodulatory mechanisms can be identified in parasitic nematodes infecting insects, plants, and mammals and vary greatly in the specific tactics by which the parasites modify the host immune response. Nematode-derived immunomodulatory effects have also been shown to affect, negatively or positively, the outcome of some concurrent diseases suffered by the host. Understanding nematode immunomodulatory actions will potentially reveal novel targets that will in turn lead to the development of effective means for the control of destructive nematode parasites.

  7. Loss of the insulator protein CTCF during nematode evolution

    Directory of Open Access Journals (Sweden)

    Schierenberg Einhard

    2009-08-01

    Full Text Available Abstract Background The zinc finger (ZF protein CTCF (CCCTC-binding factor is highly conserved in Drosophila and vertebrates where it has been shown to mediate chromatin insulation at a genomewide level. A mode of genetic regulation that involves insulators and insulator binding proteins to establish independent transcriptional units is currently not known in nematodes including Caenorhabditis elegans. We therefore searched in nematodes for orthologs of proteins that are involved in chromatin insulation. Results While orthologs for other insulator proteins were absent in all 35 analysed nematode species, we find orthologs of CTCF in a subset of nematodes. As an example for these we cloned the Trichinella spiralis CTCF-like gene and revealed a genomic structure very similar to the Drosophila counterpart. To investigate the pattern of CTCF occurrence in nematodes, we performed phylogenetic analysis with the ZF protein sets of completely sequenced nematodes. We show that three ZF proteins from three basal nematodes cluster together with known CTCF proteins whereas no zinc finger protein of C. elegans and other derived nematodes does so. Conclusion Our findings show that CTCF and possibly chromatin insulation are present in basal nematodes. We suggest that the insulator protein CTCF has been secondarily lost in derived nematodes like C. elegans. We propose a switch in the regulation of gene expression during nematode evolution, from the common vertebrate and insect type involving distantly acting regulatory elements and chromatin insulation to a so far poorly characterised mode present in more derived nematodes. Here, all or some of these components are missing. Instead operons, polycistronic transcriptional units common in derived nematodes, seemingly adopted their function.

  8. The bacterial community of entomophilic nematodes and host beetles.

    Science.gov (United States)

    Koneru, Sneha L; Salinas, Heilly; Flores, Gilberto E; Hong, Ray L

    2016-05-01

    Insects form the most species-rich lineage of Eukaryotes and each is a potential host for organisms from multiple phyla, including fungi, protozoa, mites, bacteria and nematodes. In particular, beetles are known to be associated with distinct bacterial communities and entomophilic nematodes. While entomopathogenic nematodes require symbiotic bacteria to kill and reproduce inside their insect hosts, the microbial ecology that facilitates other types of nematode-insect associations is largely unknown. To illuminate detailed patterns of the tritrophic beetle-nematode-bacteria relationship, we surveyed the nematode infestation profiles of scarab beetles in the greater Los Angeles area over a five-year period and found distinct nematode infestation patterns for certain beetle hosts. Over a single season, we characterized the bacterial communities of beetles and their associated nematodes using high-throughput sequencing of the 16S rRNA gene. We found significant differences in bacterial community composition among the five prevalent beetle host species, independent of geographical origin. Anaerobes Synergistaceae and sulphate-reducing Desulfovibrionaceae were most abundant in Amblonoxia beetles, while Enterobacteriaceae and Lachnospiraceae were common in Cyclocephala beetles. Unlike entomopathogenic nematodes that carry bacterial symbionts, insect-associated nematodes do not alter the beetles' native bacterial communities, nor do their microbiomes differ according to nematode or beetle host species. The conservation of Diplogastrid nematodes associations with Melolonthinae beetles and sulphate-reducing bacteria suggests a possible link between beetle-bacterial communities and their associated nematodes. Our results establish a starting point towards understanding the dynamic interactions between soil macroinvertebrates and their microbiota in a highly accessible urban environment.

  9. Anthelmintic efficacy and dose determination of Albizia anthelmintica against gastrointestinal nematodes in naturally infected Ugandan sheep.

    Science.gov (United States)

    Gradé, J T; Arble, B L; Weladji, R B; Van Damme, P

    2008-11-07

    Weight loss, stunted growth, and death caused by gastrointestinal parasites are major constraints to livestock productivity, especially in tropical and developing countries where regular use, and misuse, of anthelmintics has led to nematode resistance. Albizia anthelmintica Brong. (Fabaceae) is traditionally employed throughout East Africa to treat helminth parasitosis in livestock. Reported efficacy has varied from 90% against mixed nematodes to just 19% against Haemonchus contortus alone. The objective of this study was to assess the anthelmintic effect of A. anthelmintica against naturally occurring infections of mixed gastrointestinal parasites, and to establish an effective treatment dose, in sheep under pastoral field conditions of northern Uganda. A. anthelmintica bark was collected and prepared according to local custom and packed into gel capsules. Fifty-five young female local mixed-breed lambs were randomly assigned to six groups, including a positive control group that received levamisole (synthetic anthelmintic) and a negative control group that received no treatment. Following the World Association for the Advancement of Veterinary Parasitology (WAAVP) dose determination guidelines, the other four groups were treated with varying doses of A. anthelmintica. Statistical analyses (using generalized linear models) were performed to assess treatment effect. There was a significant treatment (group) effect on parasite egg/oocyte counts per gram (EPG) for nematodes, but not for coccidia. The most effective dose against nematodes (0.8g, 58.7mg/kg) closely approximates what is usually given by traditional healers, 0.9g/adult sheep. It provided major and significant reduction in EPG as compared to the negative control. Anthelmintic efficacy was estimated using percent faecal egg count reduction (FECR). Other than the positive control, animals in the standard dose group showed the greatest decline in shedding of nematode eggs, with an FECR of 78%. This study

  10. A new method for studying population genetics of cyst nematodes based on Pool-Seq and genomewide allele frequency analysis.

    Science.gov (United States)

    Mimee, Benjamin; Duceppe, Marc-Olivier; Véronneau, Pierre-Yves; Lafond-Lapalme, Joël; Jean, Martine; Belzile, François; Bélair, Guy

    2015-11-01

    Cyst nematodes are important agricultural pests responsible for billions of dollars of losses each year. Plant resistance is the most effective management tool, but it requires a close monitoring of population genetics. Current technologies for pathotyping and genotyping cyst nematodes are time-consuming, expensive and imprecise. In this study, we capitalized on the reproduction mode of cyst nematodes to develop a simple population genetic analysis pipeline based on genotyping-by-sequencing and Pool-Seq. This method yielded thousands of SNPs and allowed us to study the relationships between populations of different origins or pathotypes. Validation of the method on well-characterized populations also demonstrated that it was a powerful and accurate tool for population genetics. The genomewide allele frequencies of 23 populations of golden nematode, from nine countries and representing the five known pathotypes, were compared. A clear separation of the pathotypes and fine genetic relationships between and among global populations were obtained using this method. In addition to being powerful, this tool has proven to be very time- and cost-efficient and could be applied to other cyst nematode species.

  11. RNAi and functional genomics in plant parasitic nematodes.

    Science.gov (United States)

    Rosso, M N; Jones, J T; Abad, P

    2009-01-01

    Plant nematology is currently undergoing a revolution with the availability of the first genome sequences as well as comprehensive expressed sequence tag (EST) libraries from a range of nematode species. Several strategies are being used to exploit this wealth of information. Comparative genomics is being used to explore the acquisition of novel genes associated with parasitic lifestyles. Functional analyses of nematode genes are moving toward larger scale studies including global transcriptome profiling. RNA interference (RNAi) has been shown to reduce expression of a range of plant parasitic nematode genes and is a powerful tool for functional analysis of nematode genes. RNAi-mediated suppression of genes essential for nematode development, survival, or parasitism is revealing new targets for nematode control. Plant nematology in the genomics era is now facing the challenge to develop RNAi screens adequate for high-throughput functional analyses.

  12. Rolling circle amplification of complete nematode mitochondrial genomes.

    Science.gov (United States)

    Tang, Sha; Hyman, Bradley C

    2005-06-01

    To enable investigation of nematode mitochondrial DNA evolution, methodology has been developed to amplify intact nematode mitochondrial genomes in preparative yields using a rolling circle replication strategy. Successful reactions were generated from whole cell template DNA prepared by alkaline lysis of the rhabditid nematode Caenorhabditis elegans and a mermithid nematode, Thaumamermis cosgrovei. These taxa, representing the two major nematode classes Chromodorea and Enoplea, maintain mitochondrial genomes of 13.8 kb and 20.0 kb, respectively. Efficient amplifications were conducted on template DNA isolated from individual or pooled nematodes that were alive or stored at -80 degrees C. Unexpectedly, these experiments revealed that multiple T. cosgrovei mitochondrial DNA haplotypes are maintained in our local population. Rolling circle amplification products can be used as templates for standard PCR reactions with specific primers that target mitochondrial genes or for direct DNA sequencing.

  13. Video capture and editing as a tool for the storage, distribution, and illustration of morphological characters of nematodes.

    Science.gov (United States)

    De Ley, Paul; Bert, Wim

    2002-12-01

    Morphological identification and detailed observation of nematodes usually requires permanent slides, but these are never truly permanent and often prevent the same specimens to be used for other purposes. To efficiently record the morphology of nematodes in a format that allows easy archiving, editing, and distribution, we have assembled two micrographic video capture and editing (VCE) configurations. These assemblies allow production of short video clips that mimic multifocal observation of nematode specimens through a light microscope. Images so obtained can be used for training, management, and online access of "virtual voucher specimens" in taxonomic collections, routine screening of fixed or unfixed specimens, recording of ephemeral staining patterns, or recording of freshly dissected internal organs prior to their decomposition. We provide an overview of the components and operation of both of our systems and evaluate their efficiency and image quality. We conclude that VCE is a highly versatile approach that is likely to become widely used in nematology research and teaching.

  14. Immunity to gastrointestinal nematodes: mechanisms and myths.

    Science.gov (United States)

    Grencis, Richard K; Humphreys, Neil E; Bancroft, Allison J

    2014-07-01

    Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30-40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense.

  15. Mucocutaneous manifestations of helminth infections: Nematodes.

    Science.gov (United States)

    Lupi, Omar; Downing, Christopher; Lee, Michael; Pino, Livia; Bravo, Francisco; Giglio, Patricia; Sethi, Aisha; Klaus, Sidney; Sangueza, Omar P; Fuller, Claire; Mendoza, Natalia; Ladizinski, Barry; Woc-Colburn, Laila; Tyring, Stephen K

    2015-12-01

    In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus.

  16. Computational and phylogenetic validation of nematode horizontal gene transfer

    OpenAIRE

    Bird David; Scholl Elizabeth H

    2011-01-01

    Abstract Sequencing of expressed genes has shown that nematodes, particularly the plant-parasitic nematodes, have genes purportedly acquired from other kingdoms by horizontal gene transfer. The prevailing orthodoxy is that such transfer has been a driving force in the evolution of niche specificity, and a recent paper in BMC Evolutionary Biology that presents a detailed phylogenetic analysis of cellulase genes in the free-living nematode Pristionchus pacificus at the species, genus and family...

  17. Intraocular nematode with diffuse unilateral subacute neuroretinitis: case report

    OpenAIRE

    Zakariah Sakinah; Said Mariyani; Alwi Azma-Azalina; Yusoff Munira,; Ghani Zulkifli; Zunaina Embong

    2011-01-01

    Abstract Background Live intraocular nematode is a rare occurrence. Nematode can migrate actively within the eye, creating visual symptoms and damaging ocular tissue. Case presentation A 26-year old man presented with painless reduced vision of the left eye for one week duration. It was associated with floaters. Visual acuity on the left eye was hand movement. Anterior segment examination was normal with normal intra-ocular pressure. Fundus examination showed a live nematode lying subretinall...

  18. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    OpenAIRE

    Manosalva, P; Manohar, M; von Reuss, S.; Chen, S.; Koch, A; Kaplan, F; Choe, A.; Micikas, R.; X. Wang; Kogel, K.; Sternberg, P.; Williamson, V; Schroeder, D; Klessig, F.

    2015-01-01

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentratio...

  19. Metal stress in free-living nematodes

    OpenAIRE

    Hamelijnck-Arts, M.S.J.

    2001-01-01

    Terrestrial invertebrates offer meaningful targets for assessing the potential adverse effects of chemicals on soil ecosystems. Invertebrates play a major role in the functioning of the soil ecosystem by enhancing the soil structure, mineralization and the decomposition of organic material, and because of their role in the foodweb. The most dominant group of terrestrial invertebrates, in fact of all multicellular organisms on earth, are nematodes, also called threadworms or roundworms. Nemato...

  20. Bacillus thuringiensis crystal proteins that target nematodes

    OpenAIRE

    Wei, Jun-Zhi; Hale, Kristina; Carta, Lynn; Platzer, Edward; Wong, Cynthie; Fang, Su-Chiung; Aroian, Raffi V.

    2003-01-01

    Bacillus thuringiensis (Bt) crystal proteins are pore-forming toxins used as insecticides around the world. Previously, the extent to which these proteins might also target the invertebrate phylum Nematoda has been mostly ignored. We have expressed seven different crystal toxin proteins from two largely unstudied Bt crystal protein subfamilies. By assaying their toxicity on diverse free-living nematode species, we demonstrate that four of these crystal proteins are active against multiple nem...

  1. Assaying environmental nickel toxicity using model nematodes.

    Science.gov (United States)

    Rudel, David; Douglas, Chandler D; Huffnagle, Ian M; Besser, John M; Ingersoll, Christopher G

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  2. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  3. Prevalence of intestinal nematodes in alcoholic patients

    Directory of Open Access Journals (Sweden)

    Zago-Gomes Maria P.

    2002-01-01

    Full Text Available We report the results of a retrospective study on the frequency of intestinal nematodes among 198 alcoholic and 440 nonalcoholic patients at the University Hospital Cassiano Antonio Moraes in Vitória, ES, Brazil. The control sample included 194 nonalcoholic patients matched according to age, sex and neighborhood and a random sample of 296 adults admitted at the same hospital. Stool examination by sedimentation method (three samples was performed in all patients. There was a significantly higher frequency of intestinal nematodes in alcoholics than in controls (35.3% and 19.2%, respectively, due to a higher frequency of Strongyloides stercoralis (21.7% and 4.1%, respectively. Disregarding this parasite, the frequency of the other nematodes was similar in both groups. The higher frequency of S. stercoralis infection in alcoholics could be explained by immune modulation and/or by some alteration in corticosteroid metabolism induced by chronic ethanol ingestion. Corticosteroid metabolites would mimic the worm ecdisteroids, that would in turn increase the fecundity of females in duodenum and survival of larvae. Consequently, the higher frequency of Strongyloides larvae in stool of alcoholics does not necessarily reflect an increased frequency of infection rate, but only an increased chance to present a positive stool examination using sedimentation methods.

  4. Acetylcholinesterase genes in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Combes, D; Fedon, Y; Toutant, J P; Arpagaus, M

    2001-01-01

    Acetylcholinesterase (AChE, EC 3.1.1.7) is responsible for the termination of cholinergic nerve transmission. It is the target of organophosphates and carbamates, two types of chemical pesticides being used extensively in agriculture and veterinary medicine against insects and nematodes. Whereas there is usually one single gene encoding AChE in insects, nematodes are one of the rare phyla where multiple ace genes have been unambiguously identified. We have taken advantage of the nematode Caenorhabditis elegans model to identify the four genes encoding AChE in this species. Two genes, ace-1 and ace-2, encode two major AChEs with different pharmacological properties and tissue repartition: ace-1 is expressed in muscle cells and a few neurons, whereas ace-2 is mainly expressed in motoneurons. ace-3 represents a minor proportion of the total AChE activity and is expressed only in a few cells, but it is able to sustain double null mutants ace-1; ace-2. It is resistant to usual cholinesterase inhibitors. ace-4 was transcribed but the corresponding enzyme was not detected in vivo.

  5. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  6. A white paper on nematode comparative genomics.

    Science.gov (United States)

    Bird, David McK; Blaxter, Mark L; McCarter, James P; Mitreva, Makedonka; Sternberg, Paul W; Thomas, W Kelley

    2005-12-01

    In response to the new opportunities for genome sequencing and comparative genomics, the Society of Nematology (SON) formed a committee to develop a white paper in support of the broad scientific needs associated with this phylum and interests of SON members. Although genome sequencing is expensive, the data generated are unique in biological systems in that genomes have the potential to be complete (every base of the genome can be accounted for), accurate (the data are digital and not subject to stochastic variation), and permanent (once obtained, the genome of a species does not need to be experimentally re-sampled). The availability of complete, accurate, and permanent genome sequences from diverse nematode species will underpin future studies into the biology and evolution of this phylum and the ecological associations (particularly parasitic) nematodes have with other organisms. We anticipate that upwards of 100 nematode genomes will be solved to varying levels of completion in the coming decade and suggest biological and practical considerations to guide the selection of the most informative taxa for sequencing.

  7. Nematode locomotion in unconfined and confined fluids

    Science.gov (United States)

    Bilbao, Alejandro; Wajnryb, Eligiusz; Vanapalli, Siva A.; Blawzdziewicz, Jerzy

    2013-08-01

    The millimeter-long soil-dwelling nematode Caenorhabditis elegans propels itself by producing undulations that propagate along its body and turns by assuming highly curved shapes. According to our recent study [V. Padmanabhan et al., PLoS ONE 7, e40121 (2012), 10.1371/journal.pone.0040121] all these postures can be accurately described by a piecewise-harmonic-curvature model. We combine this curvature-based description with highly accurate hydrodynamic bead models to evaluate the normalized velocity and turning angles for a worm swimming in an unconfined fluid and in a parallel-wall cell. We find that the worm moves twice as fast and navigates more effectively under a strong confinement, due to the large transverse-to-longitudinal resistance-coefficient ratio resulting from the wall-mediated far-field hydrodynamic coupling between body segments. We also note that the optimal swimming gait is similar to the gait observed for nematodes swimming in high-viscosity fluids. Our bead models allow us to determine the effects of confinement and finite thickness of the body of the nematode on its locomotion. These effects are not accounted for by the classical resistive-force and slender-body theories.

  8. In vitro nematicidal activity of naphthoquinones against the root-lesion nematode Pratylenchus thornei

    Directory of Open Access Journals (Sweden)

    Ivânia ESTEVES

    2017-05-01

    Full Text Available The root-lesion nematode Pratylenchus thornei is a widely distributed and important parasite of cereals and legumes. As migratory endoparasites, P. thornei are difficult to manage  because they enter and leave host roots and may remain quiescent inside roots or in soil when conditions are unfavourable for plant growth. The number of available nematicides to manage these nematodes is restricted, so new, effective and eco-friendly sustainable management strategies are needed. The effects of naphthoquinones (juglone, 1,4-naphtoquinone and plumbagin produced by some plants species, including walnut (Juglandaceae, were assessed against P. thornei. An additional treatment of a mixture of juglone and 1,4-naphtoquinone (2:1, w/w, was included because these compounds are frequently found at these propotion in walnut extracts. Juveniles and adult nematodes were exposed to different concentrations of each naphthoquinone and nematode mortality was assessed. Juglone and 1,4-naphthoquinone (at 500 ppm were more effective than plumbagin, and gave 100% mortality after 24 h of exposure. A synergistic effect was not detected when juglone and 1,4-naphthoquinone (2:1, w/w were combined. Estimated lethal concentrations causing 50% P. thornei mortality (LC50s (72 h exposure were: 134.7 ppm for juglone, 161.2 ppm for 1,4-naphthoquinone, 207.6 ppm for juglone + 1,4-naphthoquinone (2:1, w/w, and 178.8 ppm for plumbagin. This study has demonstrated the nematicidal potential of these naphthoquinones against P. thornei, and has shown that walnut residues may be valuable sources for extraction of these compounds.

  9. Entomopathogenic and plant pathogenic nematodes as opposing forces in agriculture.

    Science.gov (United States)

    Kenney, Eric; Eleftherianos, Ioannis

    2016-01-01

    Plant-parasitic nematodes are responsible for substantial damages within the agriculture industry every year, which is a challenge that has thus far gone largely unimpeded. Chemical nematicides have been employed with varying degrees of success, but their implementation can be cumbersome, and furthermore they could potentially be neutralising an otherwise positive effect from the entomopathogenic nematodes that coexist with plant-parasitic nematodes in soil environments and provide protection for plants against insect pests. Recent research has explored the potential of employing entomopathogenic nematodes to protect plants from plant-parasitic nematodes, while providing their standard degree of protection against insects. The interactions involved are highly complex, due to both the three-organism system and the assortment of variables present in a soil environment, but a strong collection of evidence has accumulated regarding the suppressive capacity of certain entomopathogenic nematodes and their mutualistic bacteria, in the context of limiting the infectivity of plant-parasitic nematodes. Specific factors produced by certain entomopathogenic nematode complexes during the process of insect infection appear to have a selectively nematicidal, or at least repellant, effect on plant-parasitic nematodes. Using this information, an opportunity has formed to adapt this relationship to large-scale, field conditions and potentially relieve the agricultural industry of one of its most substantial burdens. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  10. Cyst nematode-induced changes in plant development

    NARCIS (Netherlands)

    Goverse, A.

    1999-01-01

    This thesis describes a first attempt to investigate the biological activity of cyst nematode secretions on plant cell proliferation and the molecular mechanisms underlying feeding cell development in plant roots upon cyst nematode infection.

    To investigate the role of

  11. Native nematodes as new bio-insecticides for cranberries

    Science.gov (United States)

    In the summer of 2015, an effort was made in central Wisconsin to find an entomopathogenic nematode capable controlling Wisconsin’s cranberry pests. Using a standard baiting method, a nematode of the Oscheius genus was collected from the mossy, sandy, peat-filled soils of a wild cranberry marsh. Thi...

  12. Plant ectoparasitic nematodes prefer roots without their microbial enemies

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Milliano, de M.J.K.; Duyts, H.; Putten, van der W.H.

    2009-01-01

    Root-feeding nematodes are major soil-borne pests in agriculture. In natural ecosystems, their abundance can be strongly controlled by natural enemies. In coastal foredune soil, the abundance of the ectoparasitic nematode Tylenchorhynchus ventralis is controlled by local interactions with soil

  13. Transgenesis in parasitic nematodes: building a better array

    OpenAIRE

    Lok, James B.

    2009-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward.

  14. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    Science.gov (United States)

    Despite advances in medicine and crop genetics, nematodes remain significant human pathogens and agricultural pests. This warrants investigation of alternative strategies for pest control, such as interference with pheromone-mediated reproduction. Because only two nematode species have had their phe...

  15. A satellite explosion in the genome of holocentric nematodes.

    Directory of Open Access Journals (Sweden)

    Juan A Subirana

    Full Text Available Centromere sequences in the genome are associated with the formation of kinetochores, where spindle microtubules grow in mitosis. Centromere sequences usually have long tandem repeats (satellites. In holocentric nematodes it is not clear how kinetochores are formed during mitosis; they are distributed throughout the chromosomes. For this reason it appeared of interest to study the satellites in nematodes in order to determine if they offer any clue on how kinetochores are assembled in these species. We have studied the satellites in the genome of six nematode species. We found that the presence of satellites depends on whether the nematode chromosomes are holocentric or monocentric. It turns out that holocentric nematodes are unique because they have a large number of satellites scattered throughout their genome. Their number, length and composition are different in each species: they apparently have very little evolutionary conservation. In contrast, no scattered satellites are found in the monocentric nematode Trichinella spiralis. It appears that the absence/presence of scattered satellites in the genome distinguishes monocentric from holocentric nematodes. We conclude that the presence of satellites is related to the holocentric nature of the chromosomes of most nematodes. Satellites may stabilize a higher order structure of chromatin and facilitate the formation of kinetochores. We also present a new program, SATFIND, which is suited to find satellite sequences.

  16. Systematics, ecology and feeding biology of estuarine nematodes

    NARCIS (Netherlands)

    Bouwman, L.A.

    1983-01-01

    As part of extensive biological and chemical investigations in the Ems estuary, the nematode fauna of this area (mainly located in the sediments of tidal flats) was studied.First, a new method of isolating nematodes was developed, as none of the existing methods appeared to be quantitatively reliabl

  17. 76 FR 60357 - Golden Nematode; Removal of Regulated Areas

    Science.gov (United States)

    2011-09-29

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 Golden Nematode; Removal of Regulated Areas... Genesee County, NY, from the list of generally infested areas. Surveys have shown that the fields in these two townships are free of golden nematode, and we have determined that regulation of these areas is...

  18. [Resistance to anthelmintics in nematodes in sheep and goats].

    Science.gov (United States)

    Praslicka, J; Corba, J

    1995-08-01

    The article offers a brief view on the most important theoretical knowledge of resistance of gastrointestinal nematodes to anthelmintic drugs in sheep and goats. Besides the definition and basic terms, factors of development and occurrence of resistance on farm are analyzed. Furthermore, methods for detection of resistant nematodes as well as complex of recommended preventive measures are given.

  19. Control of the peachtree borer using beneficial nematodes

    Science.gov (United States)

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  20. Conserved nematode signaling molecules elicit plant defenses and pathogen resistance

    Science.gov (United States)

    Nematodes, which are ubiquitous in soil and are estimated to cause $100 B of agricultural damage annually, produce novel, highly conserved small sugar-based molecules call ascarosides. Ascarosides play critical roles in nematode development and behavior. We report here that plants recognize these un...

  1. Mapping genetic factors controlling potato/cyst nematode interactions.

    NARCIS (Netherlands)

    Rouppe van der Voort, J.N.A.M.

    1998-01-01

    The thesis describes strategies for genetic mapping of the genomes of the potato cyst nematode and potato. Mapping in cyst nematodes was achieved by AFLP genotyping of single cysts and subsequent segregation analysis in a family of sibling populations. The genetic map of Globodera rostochiensis comp

  2. Plant ectoparasitic nematodes prefer roots without their microbial enemies

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Milliano, de M.J.K.; Duyts, H.; Putten, van der W.H.

    2009-01-01

    Root-feeding nematodes are major soil-borne pests in agriculture. In natural ecosystems, their abundance can be strongly controlled by natural enemies. In coastal foredune soil, the abundance of the ectoparasitic nematode Tylenchorhynchus ventralis is controlled by local interactions with soil micro

  3. Relationships between initial population densities of Meloidogyne incognita race 2 and nematode population development in terms of variable soybean resistance.

    Science.gov (United States)

    Fourie, Hendrika; Mc Donald, Alexander H; De Waele, Dirk

    2010-03-01

    The effect of increasing initial population density levels (Pi) of Meloidogyne incognita race 2 on nematode population development and yield of a susceptible (Prima2000) and resistant (LS5995) soybean cultivar was investigated. Two experiments, one in a hail net cage and one in microplots, were conducted one each during two consecutive growing seasons at Potchefstroom in the North West Province of South Africa. Nematode reproduction was assessed by determining the number of eggs and second-stage juveniles (J2) in the rhizosphere and roots, egg masses, egg-laying females (ELF) and reproduction factor (Rf) values per root system at harvesting 110 days after planting. Percentage yield reduction in the two cultivars was also calculated. Strong non-linear relationships existed between all nematode variables as well as between Pi and percentage yield loss in both cultivars for both experiments in this study. Significantly higher numbers of eggs and J2, egg masses and ELF were maintained in the roots of the nematode-susceptible Prima2000 than in the resistant LS5995 from Pi = 100 and higher in both experiments. Rf values were inversely related to Pi for both cultivars and were lowest on LS5995, with Prima2000 maintaining significantly higher Rf values in both experiments. Yield loss in LS5995 was at least six times higher than that of Prima2000. The difference in monetary terms is demonstrated, although it is suggested that host plant resistance to plant-parasitic nematodes may not be sufficient as the only management tool in highly infested soils or in rotation systems including nematode susceptible crops.

  4. Natural genetic and induced plant resistance, as a control strategy to plant-parasitic nematodes alternative to pesticides.

    Science.gov (United States)

    Molinari, Sergio

    2011-03-01

    Plant-parasitic nematodes are pests of a wide range of economically important crops, causing severe losses to agriculture. Natural genetic resistance of plants is expected to be a valid solution of the many problems nematodes cause all over the world. Progress in resistance applications is particularly important for the less-developed countries of tropical and subtropical regions, since use of resistant cultivars may be the only possible and economically feasible control strategy in those farming systems. Resistance is being considered of particular importance also in modern high-input production systems of developed countries, as the customary reliance on chemical nematicides has been restricted or has come to an end. This review briefly describes the genetic bases of resistance to nematodes in plants and focuses on the chances and problems of its exploitation as a key element in an integrated management program. Much space is dedicated to the major problem of resistance durability, in that the intensive use of resistant cultivars is likely to increasingly induce the selection of virulent populations able to "break" the resistance. Protocols of pest-host suitability are described, as bioassays are being used to evaluate local nematode populations in their potential to be selected on resistant germplasm and endanger resistant crops. The recent progress in using robust and durable resistances against nematodes as an efficient method for growers in vegetable cropping systems is reported, as well as the possible use of chemicals that do not show any unfavorable impact on environment, to induce in plants resistance against plant-parasitic nematodes.

  5. Plant-parasitic nematodes associated with olive tree (Olea europaea L.) with a focus on the Mediterranean Basin: a review.

    Science.gov (United States)

    Ali, Nadine; Chapuis, Elodie; Tavoillot, Johannes; Mateille, Thierry

    2014-01-01

    The olive tree (Olea europaea ssp. europaea.) is one of the most ancient cultivated trees. It is an emblematic species owing to its ecological, economic and cultural importance, especially in the Mediterranean Basin. Plant-parasitic nematodes are major damaging pests on olive trees, mainly in nurseries. They significantly contribute to economic losses in the top-ten olive-producing countries in the world. However, the damages they induce in orchards and nurseries are specifically documented only in a few countries. This review aims to update knowledge about the olive-nematode pathosystem by: (1) updating the list of plant-parasitic nematodes associated with olive trees; (2) analysing their diversity (taxonomic level, trophic groups, dominance of taxa), which allowed us (i) to assess the richness observed in each country, and (ii) to exhibit and describe the most important taxa able to induce damages on olive trees such as: Meloidogyne, Pratylenchus, Helicotylenchus, Xiphinema, Tylenchulus, Rotylenchulus, Heterodera (distribution especially in the Mediterranean Basin, pathogenicity and reactions of olive trees); (3) describing some management strategies focusing on alternative control methods; (4) suggesting new approaches for controlling plant-parasitic nematodes based on the management of the diversity of their communities, which are structured by several environmental factors such as olive diversity (due to domestication of wild olive in the past, and to breeding now), cropping systems (from traditional to high-density orchards), irrigation, and terroirs.

  6. Creolina effect on the parasitic nematodes on tobacco crop

    Directory of Open Access Journals (Sweden)

    Ricardo Bemfica Steffen

    2010-06-01

    Full Text Available Tobacco is a culture with great economic importance in the Rio Grande do Sul State, It is usually cultivated in small areas using family work force. The nematodes are organisms that cause damages to the tobacco and limit the development and production. The aim of this work was to evaluate the use of the creolina as measure alternative of nematofauna control. In controlled conditions, the creolina applications solutions at 10 and 20% presented efficiency of 74 and 85% in the nematodes inactivation, respectively. In field conditions, the application of the creolina solution at 10% in revolved soil provided decrease of 50% in the total number of nematodes in the soil and it presented efficiency of 45% in the present nematodes inactivation, showed a great potential in the integrated handling of nematodes in small cultivated areas with tabacum.

  7. BASIDIOMYCETE-BASED METHOD FOR BIOCONTROL OF PHYTOPATHOGENIC NEMATODES

    Directory of Open Access Journals (Sweden)

    Tiberius BALAEŞ

    2015-12-01

    Full Text Available Phytopathogenic nematodes represent one of the most important groups of pathogens in crops. The use of chemical to control the nematodes attack in crops is decreasing every year due to the concern of the toxicity and side effects of such compounds. In the course for finding alternatives to the use of chemicals, biological control of nematodes is gaining much attention. Some saprotrophic fungi are able to feed on invertebrates, thus becoming efficient agents of control. In this study, three species of basidiomycetes were analyzed for their potential to be used as control agents of phytopathogenic nematodes. Through on in vitro investigation of these potential, one strain – Gymnopilus junonius was further selected for a pot test against Meloidogyne incognita, a very important phytopathogenic species of nematodes. The fungal treatment strongly decreased the M. incognita population on the tested pots, proving the potential of G. junonius strain to be used in biocontrol.

  8. Chitosan Increases Tomato Root Colonization by Pochonia chlamydosporia and Their Combination Reduces Root-Knot Nematode Damage

    Directory of Open Access Journals (Sweden)

    Nuria Escudero

    2017-09-01

    Full Text Available The use of biological control agents could be a non-chemical alternative for management of Meloidogyne spp. [root-knot nematodes (RKN], the most damaging plant-parasitic nematodes for horticultural crops worldwide. Pochonia chlamydosporia is a fungal parasite of RKN eggs that can colonize endophytically roots of several cultivated plant species, but in field applications the fungus shows a low persistence and efficiency in RKN management. The combined use of P. chlamydosporia with an enhancer could help its ability to develop in soil and colonize roots, thereby increasing its efficiency against nematodes. Previous work has shown that chitosan enhances P. chlamydosporia sporulation and production of extracellular enzymes, as well as nematode egg parasitism in laboratory bioassays. This work shows that chitosan at low concentrations (up to 0.1 mg ml-1 do not affect the viability and germination of P. chlamydosporia chlamydospores and improves mycelial growth respect to treatments without chitosan. Tomato plants irrigated with chitosan (same dose limit increased root weight and length after 30 days. Chitosan irrigation increased dry shoot and fresh root weight of tomato plants inoculated with Meloidogyne javanica, root length when they were inoculated with P. chlamydosporia, and dry shoot weight of plants inoculated with both P. chlamydosporia and M. javanica. Chitosan irrigation significantly enhanced root colonization by P. chlamydosporia, but neither nematode infection per plant nor fungal egg parasitism was affected. Tomato plants cultivated in a mid-suppressive (29.3 ± 4.7% RKN egg infection non-sterilized clay loam soil and irrigated with chitosan had enhanced shoot growth, reduced RKN multiplication, and disease severity. Chitosan irrigation in a highly suppressive (73.7 ± 2.6% RKN egg infection sterilized-sandy loam soil reduced RKN multiplication in tomato. However, chitosan did not affect disease severity or plant growth irrespective of

  9. Co-adaptation mechanisms in plant-nematode systems.

    Science.gov (United States)

    Zinovieva, S V

    2014-01-01

    The review is aimed to analyze the biochemical and immune-breaking adaptive mechanisms established in evolution of plant parasitic nematodes. Plant parasitic nematodes are obligate, biotrophic pathogens of numerous plant species. These organisms cause dramatic changes in the morphology and physiology of their hosts. The group of sedentary nematodes which are among the most damaging plant-parasitic nematodes cause the formation of special organs called nematode feeding sites in the root tissue called syncytium (cyst nematodes, CN; Heterodera and Globodera spp.) or giant cells (root-knot nematodes, RKN; Meloidogyne spp.). The most pronounced morphological adaptations of nematodes for plant parasitism include a hollow, protrusible stylet (feeding spear) connected to three esophageal gland cells that express products secreted into plant tissues through the stylet. Several gene products secreted by the nematode during parasitism have been identified. The current battery of candidate parasitism proteins secreted by nematodes to modify plant tissues for parasitism includes cell-wall-modifying enzymes, multiple regulators of host cell cycle and metabolism, proteins that can localize near the plant cell nucleus, potential suppressors of host defense, and mimics of plant molecules. Plants are usually able to recognize and react to parasites by activating various defense responses. When the response of the plant is too weak or too late, a successful infection (compatible interaction) will result. A rapid and strong defense response (e. g. due to the presence of a resistance gene) will result in the resistant (incompatible) reaction. Defense responses include the production of toxic oxygen radicals and systemic signaling compounds as well as the activation of defense genes that lead to the production of structural barriers or other toxins.

  10. Assessment of nematode biodiversity using DGGE of 18S rDNA following extraction of nematodes from soil

    NARCIS (Netherlands)

    Foucher, A.L.J.L.; Bongers, A.M.T.; Noble, L.R.; Wilson, M.J.

    2004-01-01

    Soil nematodes are both taxonomically and functionally diverse, respond quickly to soil perturbation and have much potential as indicators of soil health. However, because of the perceived difficulty of identifying nematodes to species level morphologically, they are frequently neglected in soil eco

  11. Mining the secretome of root-knot nematodes for cell wall modifying proteins

    NARCIS (Netherlands)

    Roze, E.H.A.

    2008-01-01

    The products of parasitism genes in nematodes must be secreted to reach their targets at the nematode-plant interface. These nematode secretory proteins are therefore recognised to play an important role in the nematode-plant interaction and as a result have been subject of intense study for years.

  12. Mining the secretome of root-knot nematodes for cell wall modifying proteins

    NARCIS (Netherlands)

    Roze, E.H.A.

    2008-01-01

    The products of parasitism genes in nematodes must be secreted to reach their targets at the nematode-plant interface. These nematode secretory proteins are therefore recognised to play an important role in the nematode-plant interaction and as a result have been subject of intense study for years.

  13. Effect of winter cover crops on nematode population levels in north Florida.

    Science.gov (United States)

    Wang, K-H; McSorley, R; Gallaher, R N

    2004-12-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor x S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P winter cover crops present at the time of sampling. Plots planted to sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida.

  14. Use of nematophagous fungi in biological control of gastrointestinal nematodes in sheeps

    Directory of Open Access Journals (Sweden)

    García, Diego José

    2016-04-01

    Full Text Available The control of gastrointestinal nematodes in sheep is almost exclusively done with chemical products that generally offer good results, however inappropriate use has generated the presence of resistance in some parasitic groups. Consistent with this, and taking into account that there is a growing concern directed towards the consumption of safe food that favour human health, has sought develop new methods of biological control that manage and control the presence of gastrointestinal parasites inside of livestock farms through the use of natural enemies against these pathogens in the environment. The nematopahgous fungi, which have properties such as the reduction of the number of larvae of nematodes in fecal matter and ease of passing through the gastrointestinal tract while preserving its germinative capacity, which facilitates the possibility of developing various forms of administration are among the more biological methods for the control of gastrointestinal nematodes in sheep. In the present review were the species of fungi nematophagous most commonly used, as well as the different forms of administration tested today.

  15. The nematicidal effect of camellia seed cake on root-knot nematode Meloidogyne javanica of banana.

    Directory of Open Access Journals (Sweden)

    Xiujuan Yang

    Full Text Available Suppression of root-knot nematodes is crucially important for maintaining the worldwide development of the banana industry. Growing concerns about human and environmental safety have led to the withdrawal of commonly used nematicides and soil fumigants, thus motivating the development of alternative nematode management strategies. In this study, Meloidogyne javanica was isolated, and the nematicidal effect of Camellia seed cake on this pest was investigated. The results showed that in dish experiments, Camellia seed cake extracts under low concentration (2 g/L showed a strong nematicidal effect. After treatment for 72 h, the eggs of M. javanica were gradually dissolved, and the intestine of the juveniles gradually became indistinct. Nematicidal compounds, including saponins identified by HPLC-ESI-MS and 8 types of volatile compounds identified by GC-MS, exhibited effective nematicidal activities, especially 4-methylphenol. The pot experiments demonstrated that the application of Camellia seed cake suppressed M. javanica, and promoted the banana plant growth. This study explored an effective nematicidal agent for application in soil and revealed its potential mechanism of nematode suppression.

  16. The Nematicidal Effect of Camellia Seed Cake on Root-Knot Nematode Meloidogyne javanica of Banana

    Science.gov (United States)

    Yang, Xiujuan; Wang, Xuan; Wang, Kang; Su, Lanxi; Li, Hongmei; Li, Rong; Shen, Qirong

    2015-01-01

    Suppression of root-knot nematodes is crucially important for maintaining the worldwide development of the banana industry. Growing concerns about human and environmental safety have led to the withdrawal of commonly used nematicides and soil fumigants, thus motivating the development of alternative nematode management strategies. In this study, Meloidogyne javanica was isolated, and the nematicidal effect of Camellia seed cake on this pest was investigated. The results showed that in dish experiments, Camellia seed cake extracts under low concentration (2 g/L) showed a strong nematicidal effect. After treatment for 72 h, the eggs of M. javanica were gradually dissolved, and the intestine of the juveniles gradually became indistinct. Nematicidal compounds, including saponins identified by HPLC-ESI-MS and 8 types of volatile compounds identified by GC-MS, exhibited effective nematicidal activities, especially 4-methylphenol. The pot experiments demonstrated that the application of Camellia seed cake suppressed M. javanica, and promoted the banana plant growth. This study explored an effective nematicidal agent for application in soil and revealed its potential mechanism of nematode suppression. PMID:25849382

  17. Nematode Locomotion in Unconfined and Confined Fluids

    CERN Document Server

    Bilbao, Alejandro; Vanapalli, Siva; Blawzdziewicz, Jerzy

    2013-01-01

    The millimeter-long soil-dwelling nematode {\\it C. elegans} propels itself by producing undulations that propagate along its body and turns by assuming highly curved shapes. According to our recent study [PLoS ONE \\textbf{7}, e40121 (2012)] all these postures can be accurately described by a piecewise-harmonic-curvature (PHC) model. We combine this curvature-based description with highly accurate hydrodynamic bead models to evaluate the normalized velocity and turning angles for a worm swimming in an unconfined fluid and in a parallel-wall cell. We find that the worm moves twice as fast and navigates more effectively under a strong confinement, due to the large transverse-to-longitudinal resistance-coefficient ratio resulting from the wall-mediated far-field hydrodynamic coupling between body segments. We also note that the optimal swimming gait is similar to the gait observed for nematodes swimming in high-viscosity fluids. Our bead models allow us to determine the effects of confinement and finite thickness...

  18. Biology and predatory attributes of a diplogasterid nematode, Fictor composticola Khan et al., 2008

    Directory of Open Access Journals (Sweden)

    Bajaj H. K.

    2015-02-01

    Full Text Available Biology of Fictor composticola has been studied on Aphelenchus avenae in vitro. It reproduces by amphimixis, embryonic development is completed in 24 - 27 h and life cycle in 3 - 4 days. Fusion of sperm and egg pronuclei occurs in the uteri. Pulsation of median oesophageal bulb and pressing of lips against egg shell is seen just prior to hatching but teeth seem to play no role in this process. No moulting occurs inside the egg shell and the first stage juvenile hatches out. Female and male undergo mating upon addition of water in the culture plates and continue to swim in copula for a considerable time. A female lays 1.6 - 4.0 eggs in 24 h while feeding upon A. radicicolus. Predation and reproduction is affected by the temperature and 25 - 35 °C is the optimum range for these phenomena. Process of feeding as recorded with a CCTV attached to a compound microscope is described. F. composticola engulfs small preys; sucks the intestinal contents while holding them or cuts the body wall of large-sized preys and then feeds on prolapsed organs. Two sexes differ in their efficiencies of predation, a female on an average kills 53 A. avenae as compared to 11 by a male in 24 h. F. composticola feeds and reproduces on mycophagous nematodes and juveniles of root- knot, cyst and citrus nematodes but does not prey upon adult nematodes having coarsely annulated cuticle. Cannibalism in this species is also observed. F. composticola and Seinura paratenuicaudata prey upon each other. Biocontrol potential of F. composticola for managing nematode problems in button mushroom and agricultural crops has also been discussed.

  19. Pack hunting by a common soil amoeba on nematodes.

    Science.gov (United States)

    Geisen, Stefan; Rosengarten, Jamila; Koller, Robert; Mulder, Christian; Urich, Tim; Bonkowski, Michael

    2015-11-01

    Soils host the most complex communities on Earth, including the most diverse and abundant eukaryotes, i.e. heterotrophic protists. Protists are generally considered as bacterivores, but evidence for negative interactions with nematodes both from laboratory and field studies exist. However, direct impacts of protists on nematodes remain unknown. We isolated the soil-borne testate amoeba Cryptodifflugia operculata and found a highly specialized and effective pack-hunting strategy to prey on bacterivorous nematodes. Enhanced reproduction in presence of prey nematodes suggests a beneficial predatory life history of these omnivorous soil amoebae. Cryptodifflugia operculata appears to selectively impact the nematode community composition as reductions of nematode numbers were species specific. Furthermore, we investigated 12 soil metatranscriptomes from five distinct locations throughout Europe for 18S ribosomal RNA transcripts of C. operculata. The presence of C. operculata transcripts in all samples, representing up to 4% of the active protist community, indicates a potential ecological importance of nematophagy performed by C. operculata in soil food webs. The unique pack-hunting strategy on nematodes that was previously unknown from protists, together with molecular evidence that these pack hunters are likely to be abundant and widespread in soils, imply a considerable importance of the hitherto neglected trophic link 'nematophagous protists' in soil food webs.

  20. Unraveling flp-11/flp-32 dichotomy in nematodes.

    Science.gov (United States)

    Atkinson, Louise E; Miskelly, Iain R; Moffett, Christy L; McCoy, Ciaran J; Maule, Aaron G; Marks, Nikki J; Mousley, Angela

    2016-10-01

    FMRFamide-like peptide (FLP) signalling systems are core to nematode neuromuscular function. Novel drug discovery efforts associated with nematode FLP/FLP receptor biology are advanced through the accumulation of basic biological data that can reveal subtle complexities within the neuropeptidergic system. This study reports the characterisation of FMRFamide-like peptide encoding gene-11 (flp-11) and FMRFamide-like peptide encoding gene-32 (flp-32), two distinct flp genes which encode the analogous peptide, AMRN(A/S)LVRFamide, in multiple nematode species - the only known example of this phenomenon within the FLPergic system of nematodes. Using bioinformatics, in situ hybridisation, immunocytochemistry and behavioural assays we show that: (i) flp-11 and -32 are distinct flp genes expressed individually or in tandem across multiple nematode species, where they encode a highly similar peptide; (ii) flp-11 does not appear to be the most widely expressed flp in Caenorhabditis elegans; (iii) in species expressing both flp-11 and flp-32, flp-11 displays a conserved, restricted expression pattern across nematode clades and lifestyles; (iv) in species expressing both flp-11 and flp-32, flp-32 expression is more widespread and less conserved than flp-11; (v) in species expressing only flp-11, the flp-11 expression profile is more similar to the flp-32 profile observed in species expressing both; and (vi) FLP-11 peptides inhibit motor function in multiple nematode species. The biological significance and evolutionary origin of flp-11 and -32 peptide duplication remains unclear despite attempts to identify a common ancestor; this may become clearer as the availability of genomic data improves. This work provides insight into the complexity of the neuropeptidergic system in nematodes, and begins to examine how nematodes may compensate for structural neuronal simplicity. From a parasite control standpoint, this work underscores the importance of basic biological data, and has

  1. Suppression of plant parasitic nematodes in the chinampa agricultural soils.

    Science.gov (United States)

    Zuckerman, B M; Dicklow, M B; Coles, G C; Garcia-E, R; Marban-Mendoza, N

    1989-06-01

    Soil from the chinampa agricultural system in the Valley of Mexico suppressed damage by plant-parasitic nematodes to tomatoes and beans in greenhouse and growth chamber trials. Sterilization of the chinampa soil resulted in a loss of the suppressive effect, thereby indicating that one or more biotic factors were responsible for the low incidence of nematode damage. Nine organisms were isolated from chinampa soil, which showed antinematodal properties in culture. Naturally occurring populations of plant-parasitic nematodes were of lower incidence in chinampa soil than in Chapingo soil.

  2. Coccidian and nematode infections influence prevalence of antibody to myxoma and rabbit hemorrhagic disease viruses in European rabbits.

    Science.gov (United States)

    Bertó-Moran, Alejandro; Pacios, Isabel; Serrano, Emmanuel; Moreno, Sacramento; Rouco, Carlos

    2013-01-01

    The interaction among several parasites in European rabbits (Oryctolagus cuniculus) is crucial to host fitness and to the epidemiology of myxomatosis and rabbit hemorrhagic disease. These diseases have caused significant reductions in rabbit populations on the Iberian Peninsula. Most studies have focused on the epidemiology and pathogenesis of these viruses individually, and little is known about interactions between these viruses and other parasites. Taking advantage of an experimental restocking program in Spain, the effects of coccidian and nematode infections on the probability of having detectable antibody to myxoma and rabbit hemorrhagic disease viruses were tested in European wild rabbits. For 14 mo, we monitored rabbit abundance and parasite loads (coccidia and nematodes) in three reintroduced rabbit populations. While coccidian and nematode loads explained seasonal antibody prevalences to myxoma virus, the pattern was less clear for rabbit hemorrhagic disease. Contrary to expectations, prevalence of antibody to myxoma virus was inversely proportional to coccidian load, while nematode load seemed to play a minor role. These results have implications for viral disease epidemiology and for disease management intended to increase rabbit populations in areas where they are important for ecosystem conservation.

  3. Plant nematodes in South Africa. 11. Checklist of plant nematodes of the protected areas of KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Mariette Marais

    2013-03-01

    Full Text Available Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marindae were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces.Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected.

  4. Detection and quantification of root-knot nematode (Meloidogyne javanica), lesion nematode (Pratylenchus zeae) and dagger nematode (Xiphinema elongatum) parasites of sugarcane using real-time PCR.

    Science.gov (United States)

    Berry, Shaun D; Fargette, Mireille; Spaull, Vaughan W; Morand, Serge; Cadet, Patrice

    2008-06-01

    A number of different plant parasitic nematode species are found associated with sugarcane in South Africa. Of these, the root-knot nematode (Meloidogyne javanica), the lesion nematode (Pratylenchus zeae) and the dagger nematode (Xiphinema elongatum) are potentially the most damaging pests. Identification and enumeration of the number of these nematodes are necessary for providing advice to farmers as well as studying the effects of various treatments in field and glasshouse trials. We report on the development, use, and extent of specificity of three sets of primers, for M. javanica, P. zeae and X. elongatum, and on tests to detect and quantify the number of these nematodes in soil samples using SYBR Green I dye and real-time PCR technology. Amplicons from the three target species (obtained with their respective primer sets) are discernible in size by gel electrophoresis (380bp for M. javanica, 250bp for P. zeae and 500bp for X. elongatum). Also, these amplicons have characteristic melting temperatures of 83.8 degrees C (M. javanica), 86.6 degrees C (P. zeae) and 86.1 degrees C (X. elongatum). Investigations into multiplex reactions found competition between species with M. javanica competing with P. zeae and X. elongatum. Subsequent single tube (simplex) assays, enabled the construction of calibration curves for each of the three species. These were then used for quantification of the numbers of each of these species in nematode samples extracted from the field, with a high (R2=0.83) and significant positive correlation between real-time PCR and counts performed with microscopy.

  5. Nematode parasite genes: what's in a name?

    Science.gov (United States)

    Beech, Robin N; Wolstenholme, Adrian J; Neveu, Cédric; Dent, Joseph A

    2010-07-01

    The central theme of Shakespeare's Romeo and Juliet is that names are meaningless, artificial constructs, detached from any underlying reality. By contrast, we argue that a well chosen gene name can concisely convey a wealth of relevant biological information. A consistent nomenclature adds transparency that can have a real impact on our understanding of gene function. Currently, genes in parasitic nematodes are often named ad hoc, leading to confusion that can be resolved by adherence to a nomenclature standard adapted from Caenorhabditis elegans. We demonstrate this with ligand-gated ion-channels and propose that the flood of genome data and differences between parasites and the free living C. elegans will require modification of the standard.

  6. Are nematode collections in danger of extinction?

    Science.gov (United States)

    Hockland, S; Hoestra, H

    2003-01-01

    The correct identification of pest organisms, including plant-parasitic nematodes, is the essential foundation for integrated pest programmes and government policy decisions involving trade. A plethora of identification methods have been developed but the basis for identification remains essentially morphological in nature, with invertebrate collections forming the ultimate reference facility. However, a continuing decline in funds for the preservation and curation of collections and for the development of taxonomists is leading to a deterioration in the quality of standards. The development of computer technology associated with digital images and their analysis provides the possibility of not only attracting resources but also of exposing collections to international use in ways not previously possible. The time is right to develop a European strategy to save and develop collections and taxonomy.

  7. 植物抗线虫基因与抗性机理研究进展%Advances in genes and mechanisms resistance to nematodes in plants

    Institute of Scientific and Technical Information of China (English)

    叶德友; 陈劲枫

    2012-01-01

    植物寄生线虫是严重危害农业生产的一类重要病原生物,对全球作物产量造成重大损失.抗线虫基因在植物抗线虫反应中发挥重要作用,发掘抗线虫基因并培育抗线虫品种是防治线虫病害的一条有效途径.抗线虫基因的定位与克隆对解析植物抗线虫性的分子机理做出了巨大贡献,明确线虫与寄主植物之间的互作关系及抗线虫机制,可以为制定和采取更加有效的防控策略提供借鉴.%Plant parasitic nematodes are important pathogens causing significant economic losses to crops all over the world. Nematode-resistant genes in plants play an important role against nematodes. The effective measure to control the pests is to investigate genes and screen varieties resistant to nematodes. Mapping and cloning of nema-tode-resistant genes have made a great contribution to clarifying molecular mechanisms involved in plant resistance to nematodes. Underlying interaction between nematodes and plants and its resistance mechanisms are of great interest, which can be helpful for making a more effective strategy for nematode management.

  8. (Musa AAA) root nematode control and crop yield

    African Journals Online (AJOL)

    SARAH

    2016-05-31

    May 31, 2016 ... Key words: Chemical control, Musa AAA, nematode control, nematicides. INTRODUCTION ... Thorne 1949, Sher 1968) and Helicotylenchus spp. To avoid or ... Belize with a plant density of 2000 plants ha-1. Desuckering was ...

  9. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  10. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    National Research Council Canada - National Science Library

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-01-01

    .... Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated...

  11. Nematode Faunal Response to Grassland Degradation in Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The responses of soil nematode communities to grassland degradation were studied under undegraded grassland (UG),degraded grassland (DG), and improved grassland (IG), in Horqin Sandy Land, Inner Mongolia, Northeast China. Soil samples were collected at depths of 0-10, 10-20, and 20-30 cm. Total organic carbon (TOC) and total nitrogen (TN)exhibited positive effects on the total number of nematodes and trophic groups. Significant treatment effects were found in the total number of nematodes, plant parasites, and omnivores-predators. Measures taken in the improved grassland could improve the number of omnivore-predators, especially in the deeper soil layers. Nematode richness was lower in the DG treatment than in the IG and UG treatments. The food web structure index (SI) was significantly higher in the UG and IG treatments than in the DG treatment. A higher SI suggested a food web with more trophic linkages and relatively healthy ecosystems.

  12. Potential Nematode Alarm Pheromone Induces Acute Avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Zhou, Ying; Loeza-Cabrera, Mario; Liu, Zheng; Aleman-Meza, Boanerges; Nguyen, Julie K; Jung, Sang-Kyu; Choi, Yuna; Shou, Qingyao; Butcher, Rebecca A; Zhong, Weiwei

    2017-07-01

    It is crucial for animal survival to detect dangers such as predators. A good indicator of dangers is injury of conspecifics. Here we show that fluids released from injured conspecifics invoke acute avoidance in both free-living and parasitic nematodes. Caenorhabditis elegans avoids extracts from closely related nematode species but not fruit fly larvae. The worm extracts have no impact on animal lifespan, suggesting that the worm extract may function as an alarm instead of inflicting physical harm. Avoidance of the worm extract requires the function of a cGMP signaling pathway that includes the cGMP-gated channel TAX-2/TAX-4 in the amphid sensory neurons ASI and ASK. Genetic evidence indicates that the avoidance behavior is modulated by the neurotransmitters GABA and serotonin, two common targets of anxiolytic drugs. Together, these data support a model that nematodes use a nematode-specific alarm pheromone to detect conspecific injury. Copyright © 2017 by the Genetics Society of America.

  13. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  14. Survey of fresh vegetables for nematodes, amoebae, and Salmonella.

    Science.gov (United States)

    Rude, R A; Jackson, G J; Bier, J W; Sawyer, T K; Risty, N G

    1984-01-01

    Contamination by nematodes, amoebae, and bacteria of the genus Salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. The vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. Nematode eggs and larvae were recovered by the Nacconol-ether centrifugation method. Some nematode eggs were identified as parasitic Ascaris sp.; the majority of larval nematodes were thought to be soil-dwelling species. Amoebae were recovered by rinsing the vegetables with distilled water, centrifuging the rinse water, and transferring the sediment to agar plates on which a bacterial lawn had previously been grown; trophozoites identified as the potentially pathogenic species--Acanthamoeba polyphaga, A. rhysodes, and A. castellanii--were the most common amoebae recovered on the plates. Salmonella spp. were grown from 4 of 50 samples.

  15. [Effects of phytase transgenic corn planting on soil nematode community].

    Science.gov (United States)

    Zhao, Zong-Chao; Su, Ying; Mou, Wen-Ya; Liu, Man-Qiang; Chen, Xiao-Yun; Chen, Fa-Jun

    2014-04-01

    A healthy soil ecosystem is essential for nutrient cycling and energy conversion, and the impact of exogenous genes from genetically modified crops had aroused wide concerns. Phytase transgenic corn (i. e., the inbred line BVLA430101) was issued a bio-safety certificate on 27 September 2009 in China, which could improve the efficiency of feed utilization, reduce environmental pollution caused by animal manure. In this study, the abundance of trophic groups, community structure and ecological indices of soil nematodes were studied over the growing cycle of phytase transgenic corn (ab. transgenic corn) and control conventional parental corn (ab. control corn) in the field. Totally 29 and 26 nematode genera were isolated from transgenic corn and control corn fields, respectively. The abundances of bacterivores and omnivores-predators, the total number of soil nematodes, and the Shannon index (H) were significantly greater under transgenic corn than under control corn, while the opposite trend was found for the relative abundance of herbivores and the maturity index (Sigma MI) of soil nematodes. Repeated-measures analysis of variance (ANOVA) did not detect any significant effects of transgenic corn on the composition and abundance of nematode trophic groups and ecological indices of soil nematodes. Furthermore, the Student-T test showed that the abundances of bacterivores and omnivores-predators and the total number of soil nematodes during the milk-ripe stage were significant higher in the transgenic corn field than in the control corn field. The effects of transgenic corn planting on soil nematodes might be related to the increase in the nitrogen content of field soil under transgenic corn compared to control corn.

  16. Entomopathogenic Nematodes for the Biological Control of Pest Insects

    OpenAIRE

    Ljerka Oštrec

    2001-01-01

    Entomopathogenic nematodes are part of 9 families, but only some species of these families: Heterorhabditidae, Mermithidae and Steinernematidae kill insects. Infective juveniles enter the insect host through the cuticle, or through the mouth, anus, etc., to reach the haemocel. The infective juveniles also enter the insect by the foot. After that the nematodes leave the insect who usually dies. The infective juveniles are associated with symbiotic bacterium (Xenorhabdus, Photorhabdus) which h...

  17. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    OpenAIRE

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H.; Dossey, Aaron T.; Yim, Joshua J.; Ajredini, Ramadan; Kolawa, Adam A.; Kaplan, Fatma; Alborn, Hans T.; Teal, Peter E. A.; Schroeder, Frank C.; Paul W. Sternberg; EDISON, ARTHUR S.

    2012-01-01

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fracti...

  18. Entomopathogenic Nematodes for the Biological Control of Pest Insects

    OpenAIRE

    Ljerka Oštrec

    2001-01-01

    Entomopathogenic nematodes are part of 9 families, but only some species of these families: Heterorhabditidae, Mermithidae and Steinernematidae kill insects. Infective juveniles enter the insect host through the cuticle, or through the mouth, anus, etc., to reach the haemocel. The infective juveniles also enter the insect by the foot. After that the nematodes leave the insect who usually dies. The infective juveniles are associated with symbiotic bacterium (Xenorhabdus, Photorhabdus) which h...

  19. Anaerobic Soil Disinfestation (ASD) Combined with Soil Solarization for Root-Knot Nematode Control in Vegetable and Ornamental Crops in Florida

    Science.gov (United States)

    Anaerobic soil disinfestation (ASD) combined with soil solarization continues to be evaluated for management of plant-parasitic nematodes in vegetable and ornamental crops in Florida. ASD combines organic amendments and soil saturation to stimulate microbial activity and create anaerobic conditions...

  20. Possible application of a nematophagous fungus as a biological control agent of parasitic nematodes on commercial sheep farms in South Africa

    Directory of Open Access Journals (Sweden)

    M. Faedo

    2002-07-01

    Full Text Available Biological control of parasitic nematodes of livestock is currently under development and represents another tool that may be integrated into helminth parasite control strategies. This paper presents a brief introduction to commercial sheep farming in South Africa and currently available nematode parasite control methods. These include the FAMACHA(r clinical assay, strategies of pasture management, dilution of resistant worm species by introduction of susceptible worms, breed resistant sheep and nutritional supplementation. The purpose of this paper is to outline the principles of biological control using nematophagous fungi and how it may be applied on sheep farms in South Africa.

  1. Possible application of a nematophagous fungus as a biological control agent of parasitic nematodes on commercial sheep farms in South Africa.

    Science.gov (United States)

    Faedo, M; Krecek, R C

    2002-03-01

    Biological control of parasitic nematodes of livestock is currently under development and represents another tool that may be integrated into helminth parasite control strategies. This paper presents a brief introduction to commercial sheep farming in South Africa and currently available nematode parasite control methods. These include the FAMACHA clinical assay, strategies of pasture management, dilution of resistant worm species by introduction of susceptible worms, breed resistant sheep and nutritional supplementation. The purpose of this paper is to outline the principles of biological control using nematophagous fungi and how it may be applied on sheep farms in South Africa.

  2. Diverse host-seeking behaviors of skin-penetrating nematodes.

    Directory of Open Access Journals (Sweden)

    Michelle L Castelletto

    2014-08-01

    Full Text Available Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are responsible for some of the most common neglected tropical diseases. The infective larvae of skin-penetrating nematodes are thought to search for hosts using sensory cues, yet their host-seeking behavior is poorly understood. We conducted an in-depth analysis of host seeking in the skin-penetrating human parasite Strongyloides stercoralis, and compared its behavior to that of other parasitic nematodes. We found that Str. stercoralis is highly mobile relative to other parasitic nematodes and uses a cruising strategy for finding hosts. Str. stercoralis shows robust attraction to a diverse array of human skin and sweat odorants, most of which are known mosquito attractants. Olfactory preferences of Str. stercoralis vary across life stages, suggesting a mechanism by which host seeking is limited to infective larvae. A comparison of odor-driven behavior in Str. stercoralis and six other nematode species revealed that parasite olfactory preferences reflect host specificity rather than phylogeny, suggesting an important role for olfaction in host selection. Our results may enable the development of new strategies for combating harmful nematode infections.

  3. A Device to Measure the Propulsive Power of Nematodes

    CERN Document Server

    Yuan, J; Gnatt, M; Raizen, D M; Bau, H H

    2011-01-01

    In the fluid dynamics video, we present a microfluidic device to measure the propulsive power of nematodes. The device consists of a tapered conduit filled with aqueous solution. The conduit is subjected to a DC electric field with the negative pole at the narrow end and to pressure-driven flow directed from the narrow end. The nematode is inserted at the conduit's wide end. Directed by the electric field (through electrotaxis), the nematode swims deliberately upstream toward the negative pole of the DC field. As the conduit narrows, the average fluid velocity and the drag force on the nematode increase. Eventually, the nematode arrives at an equilibrium position, at which its propulsive force balances the viscous drag force induced by the adverse flow. The equilibrium position of different animals, with similar body lengths, was measured as a function of the flow rate. The flow field around the nematode was obtained by direct numerical simulations with the experimentally imaged gait and the tapered geometry ...

  4. Communities of terrestrial nematodes after different approaches to heathland restoration

    Science.gov (United States)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  5. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance.

    Science.gov (United States)

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-07-23

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.

  6. [Responses of soil nematode communities to long-term application of inorganic fertilizers in upland red soil].

    Science.gov (United States)

    Zhang, Wei; Liu, Man-Qiang; He, Yuan-Qiu; Fan, Jian-Bo; Chen, Yan

    2014-08-01

    Soil biota plays a key role in ecosystem functioning of red soil. Based on the long-term inorganic fertilization field experiment (25-year) in an upland red soil, the impacts of different inorganic fertilization managements, including NPK (nitrogen, phosphorus and potassium fertilizers), NPKCaS (NPK plus gypsum fertilizers), NP (nitrogen and phosphorus fertilizers), NK (nitrogen and potassium fertilizers) and PK (phosphorus and potassium fertilizers), on the assemblage of soil nematodes during the growing period of peanut were investigated. Significant differences among the treatments were observed for total nematode abundance, trophic groups and ecological indices (P NPKCaS > NPK > NP > NK. The total number of nematodes was significantly higher in NPKCaS and PK than in NPK, NP and NK except in May. Plant parasitic nematodes were the dominant trophic group in all treatments excepted in NPKCaS, and their proportion ranged between 38% and 65%. The dominant trophic group in NPKCaS was bacterivores and represented 42.1%. Furthermore, the higher values of maturity index, Wasilewska index and structure index in NPKCaS indicated that the combined application of NPK and gypsum could remarkably relieve soil acidification, resulting in a more mature and stable soil food web structure. While, that of the NK had the opposite effect. In conclusion, our study suggested that the application of both gypsum and phosphate is an effective practice to improve soil quality. Moreover, the analysis of nematode assemblage is relevant to reflect the impact of different inorganic fertilizer on the red soil ecosystem.

  7. Unraveling the intraguild competition between Oscheius spp. nematodes and entomopathogenic nematodes: Implications for their natural distribution in Swiss agricultural soils.

    Science.gov (United States)

    Campos-Herrera, Raquel; Půža, Vladimir; Jaffuel, Geoffrey; Blanco-Pérez, Rubén; Čepulytė-Rakauskienė, Rasa; Turlings, Ted C J

    2015-11-01

    Entomopathogenic nematodes (EPN) are excellent biological control agents to fight soil-dwelling insect pests. In a previous survey of agricultural soils of Switzerland, we found mixtures of free-living nematodes (FLN) in the genus Oscheius, which appeared to be in intense competition with EPN. As this may have important implications for the long-term persistence of EPN, we studied this intraguild competition in detail. We hypothesized that (i) Oscheius spp. isolates act as scavengers rather than entomopathogens, and (ii) cadavers with relatively small numbers of EPN are highly suitable resources for Oscheius spp. reproduction. To study this, we identified Oscheius spp. isolated from Swiss soils, quantified the outcome of EPN/Oscheius competition in laboratory experiments, developed species-specific primers and probe for quantitative real-time PCR, and evaluated their relative occurrence in the field in the context of the soil food web. Molecular analysis (ITS/D2D3) identified MG-67/MG-69 as Oscheius onirici and MG-68 as O. tipulae (Dolichura-group). Oscheius spp. indeed behaved as scavengers, reproducing in ∼64% of frozen-killed cadavers from controlled experiments. Mixed infection in the laboratory by Oscheius spp. with low (3 IJs) or high (20 IJs) initial EPN numbers revealed simultaneous reproduction in double-exposed cadavers which resulted in a substantial reduction in the number of EPN progeny from the cadaver. This effect depended on the number of EPN in the initial inoculum and differed by EPN species; Heterorhabditis megidis was better at overcoming competition. This study reveals Oscheius spp. as facultative kleptoparasites that compete with EPN for insect cadavers. Using real-time qPCR, we were able to accurately quantify this strong competition between FLN and EPN in cadavers that were recovered after soil baiting (∼86% cadavers with >50% FLN production). The severe competition within the host cadavers and the intense management of the soils in

  8. Directional movement of entomopathogenic nematodes in response to electrical fields: Effects of species, magnitude of voltage, and infective juvenile age

    Science.gov (United States)

    Entomopathogenic nematodes respond to a variety of stimuli when foraging. Previously, we reported a directional response to electrical fields for two entomopathogenic nematode species; specifically, when electrical fields were generated on agar plates Steinernema glaseri (a nematode that utilizes a...

  9. Plant nematodes in South Africa. 12. Checklist of plant nematodes of the protected areas of the Eastern Cape Province

    Directory of Open Access Journals (Sweden)

    Mariette Marais

    2014-02-01

    Full Text Available Soil-inhabiting nematodes, including plant-parasitic nematodes, are considered to be the most abundant multicellular organisms in the soil, and of particular interest since they are an integral part of the interlocking chain of nutrient conversions. Because of their abundance and relative susceptibility to both physical and chemical changes, these organisms are used as indicator organisms. The National Collection of Nematodes (NCN consists of a core collection, the Meloidogyne Collection and the Juan Heyns Collection, which are housed at the Plant Protection Research Institute of the Agricultural Research Council in Pretoria. Vast amounts of biodiversity data are contained in NCN, and the digitising of the collection from 2007 to 2014 yielded unpublished locality information, especially datasets of plant nematodes reported from protected areas of the Eastern Cape. Two hundred and thirty plant nematode species belonging to 36 genera were reported from the Eastern Cape. Of these, only 80 were from protected areas, whilst 163 were from uncultivated areas (outside protected areas and 148 from cultivated areas. Ten species were described from protected areas, namely Criconemoides silvicola, Meloinema silvicola, Ogma tuberculatum, Paralongidorus cebensis, Paralongidorus hanliae, Scutellonema tsitsikamense, Trichodorus vandenbergae, Xiphinema erriae, Xiphinema ornatizulu and Xiphinema simplex. Only M. silvicola, O. tuberculatum, P. cebensis and S. tsitsikamense were not reported from other provinces, suggesting endemism.Conservation implications: The diversity of nematode fauna is not adequately protected as most nematode biodiversity in the Eastern Cape lies outside protected areas, with only 80 of the 230 plant-feeding nematode species in the province being reported from protected areas.

  10. Plant-parasitic Nematode Acetylcholinesterase Inhibition by Carbamate and Organophosphate Nematicides.

    Science.gov (United States)

    Opperman, C H; Chang, S

    1990-10-01

    The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was AChE from C. elegans, but response to the organophosphates was approximately equivalent. The sulfur-containing phosphate nematicides were poor inhibitors of nematode acetylcholinesterase, but treatment with an oxidizing agent greatly improved inhibition. Behavioral bioassays with living nematodes revealed a poor relationship between enzyme inhibition and expression of symptoms in live nematodes.

  11. Epidemiology and risk factors for exposure to gastrointestinal nematodes in dairy herds in northwestern Europe.

    Science.gov (United States)

    Bennema, Sita C; Vercruysse, Jozef; Morgan, Eric; Stafford, Kathryn; Höglund, Johan; Demeler, Janina; von Samson-Himmelstjerna, Georg; Charlier, Johannes

    2010-10-29

    In this survey, the epidemiology of gastrointestinal (GI) nematodes in dairy herds in five northwestern European countries was studied using a standardized Ostertagia ostertagi ELISA applied on bulk-tank milk, and a common questionnaire. The levels of exposure to GI nematodes were high in Belgium, the UK and Ireland, intermediate in Germany and low in Sweden, with a mean (95% confidence interval) ELISA result (ODR) of 0.83 (0.82-0.84) in Belgium, 0.82 (0.79-0.84) in the UK and 0.80 (0.78-0.83) in Ireland; significantly higher than the mean ODR of 0.66 (0.65-0.68) in Germany and 0.52 (0.51-0.53) in Sweden. Taking into account previous literature, these regional differences are likely to be systematic. Regional variations in exposure were significantly explained by differences in management (grazing time per day, mowing, the months of turnout, housing and anthelmintic treatment). However, after controlling for these factors, significant regional differences in levels of exposure remained, suggesting an importance for climate (temperature, rainfall) and unmeasured management factors. This study emphasizes that GI nematode-induced production losses should be considered on a large percentage of northwest European dairy herds. Proposals are made for the development of region-specific monitoring and control strategies. Further advances in this area are likely to come from intervention studies that investigate the feasibility of control measures and from studies on the potential effects of climatic conditions on shifts in levels of exposure between years and regions.

  12. Pan-phylum Comparison of Nematode Metabolic Potential.

    Directory of Open Access Journals (Sweden)

    Rahul Tyagi

    2015-05-01

    Full Text Available Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species. We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of

  13. Pan-phylum Comparison of Nematode Metabolic Potential.

    Science.gov (United States)

    Tyagi, Rahul; Rosa, Bruce A; Lewis, Warren G; Mitreva, Makedonka

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  14. Nematode assemblages in the rhizosphere of spring barley (Hordeum vulgare L.) depended on fertilisation and plant growth phase

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

    rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley......rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley...

  15. Current Status of Soil-transmitted Nematode Infection in China

    Institute of Scientific and Technical Information of China (English)

    YING-DAN CHEN; LIN-HUA TANG; LONG-QI XU

    2008-01-01

    Objective To Carry out national surveys for ascertaining the current status and trends of soil-transmitted nematode infections in China,providing scientific basis for forther developing control strategies.Methods In 1988-1992(hereinafter abbreriated as "survey in 1990"),a stratified cluster random sampling method was used in the survey.In 2001-2004(hereinafter abbreriated as "survey in 2003"),in order to compare with the survey in 1990,two-characteristic stratified cluster random sampling method was used and 687 investigation spots were sampled from the 2848 spots selected in the survey in 1990.Kato-Katz thick smear method was used to examine the eggs of soil-transmitted nematodes in fecal samples. Results The prevalence rates were 53.6% and 19.6% for soil-transmitted nematodes,14.6%and 6.120% for hookworms,44.6% and 12.7% for Ascaris lumbricoides,17.4% and 4.630% for Trichuris trichiura in survey 1990 and survey 2003,respectively.The prevalence rates of soil-transmitted nematodes were higher in 13 provinces than the average level in China in the survey in 1990.and higher in 8 provinces than the average level in the survey in 2003.The prevalence of hookworms,Ascaris lumbricoides,Trichurls trichiura and the overall prevalence of soft-transmitted nematodes were higher in females than in males.It is estimated from the results of survey in 2003 that the number of persons with soil-transmitted nematode infections in the country is about 129 million,less than that in the survey in 1990. Conclusion The prevalence of soil-transmitted nematodes has declined considerably but is still relatively high in some provinces and autonomous regions.Control activities and socioeconomic development may have contributed to the decreased prevalence.

  16. Breeding for resistance to gastrointestinal nematodes - the potential in low-input/output small ruminant production systems.

    Science.gov (United States)

    Zvinorova, P I; Halimani, T E; Muchadeyi, F C; Matika, O; Riggio, V; Dzama, K

    2016-07-30

    The control of gastrointestinal nematodes (GIN) is mainly based on the use of drugs, grazing management, use of copper oxide wire particles and bioactive forages. Resistance to anthelmintic drugs in small ruminants is documented worldwide. Host genetic resistance to parasites, has been increasingly used as a complementary control strategy, along with the conventional intervention methods mentioned above. Genetic diversity in resistance to GIN has been well studied in experimental and commercial flocks in temperate climates and more developed economies. However, there are very few report outputs from the more extensive low-input/output smallholder systems in developing and emerging countries. Furthermore, results on quantitative trait loci (QTL) associated with nematode resistance from various studies have not always been consistent, mainly due to the different nematodes studied, different host breeds, ages, climates, natural infections versus artificial challenges, infection level at sampling periods, among others. The increasing use of genetic markers (Single Nucleotide Polymorphisms, SNPs) in GWAS or the use of whole genome sequence data and a plethora of analytic methods offer the potential to identify loci or regions associated nematode resistance. Genomic selection as a genome-wide level method overcomes the need to identify candidate genes. Benefits in genomic selection are now being realised in dairy cattle and sheep under commercial settings in the more advanced countries. However, despite the commercial benefits of using these tools, there are practical problems associated with incorporating the use of marker-assisted selection or genomic selection in low-input/output smallholder farming systems breeding schemes. Unlike anthelmintic resistance, there is no empirical evidence suggesting that nematodes will evolve rapidly in response to resistant hosts. The strategy of nematode control has evolved to a more practical manipulation of host-parasite equilibrium

  17. Grafting for Management of Root-Knot Nematodes in Watermelon

    Science.gov (United States)

    Five wild watermelon (Citrullus lanatus var. citroides) germplasm lines, four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, and one commercial wild watermelon (C. lanatus spp.) cultivar were evaluated as rootstocks for watermelon in a field infested...

  18. GABA localization in the nematode Ascaris

    Energy Technology Data Exchange (ETDEWEB)

    Guastella, J.

    1988-01-01

    A histochemical approach was used to examine the distribution of GABA-associated neurons in the nematode Ascaris, an organism whose small number of morphologically simple neurons make it an excellent preparation for analyzing neuronal phenotypes. Two GABAergic markers were examined: GABA-like immunoreactivity (GLIR), a marker for endogenous stores of GABA; and ({sup 3}H)-GABA uptake, a marker for GABA uptake sites. Strong GLIR was present in the cell bodies, neurites and commissures of dorsal and ventral inhibitory motorneurons present in this region. Strong GLIR was also present in the cell bodies and processes of the four RME neurons in the nerve ring and in several other ganglionic neurons. Staining was absent in excitatory motorneurons, in ventral cord interneurons and in muscle cells and hypodermis. GABA uptake sites were found in single neural processes in both the ventral and dorsal nerve cords. ({sup 3}H)-GABA labeling was also observed in the other two RME cells and several other cephalic neurons. Four putative cholinergic excitatory motorneurons in the retrovesicular ganglion (RVG) were heavily labeled. Ventral and dorsal nerve cord inhibitory motorneurons did not take up ({sup 3}H)-GABA. Labeling of the ventral cord excitatory motorneuron somata and cell bodies was at or slightly above background. Heavy labeling of muscle cells was also observed.

  19. Biodiversity of entomopathogenic nematodes in Italy.

    Science.gov (United States)

    Tarasco, E; Clausi, M; Rappazzo, G; Panzavolta, T; Curto, G; Sorino, R; Oreste, M; Longo, A; Leone, D; Tiberi, R; Vinciguerra, M T; Triggiani, O

    2015-05-01

    An investigation was carried out on the distribution and biodiversity of steinernematid and heterorhabdtid entomopathogenic nematodes (EPN) in nine regions of Italy in the period 1990-2010. More than 2000 samples were collected from 580 localities and 133 of them yielded EPN specimens. A mapping of EPN distribution in Italy showed 133 indigenous EPN strains belonging to 12 species: 43 isolates of Heterorhabditis bacteriophora, 1 of H. downesi, 1 of H. megidis, 51 of Steinernema feltiae, 12 of S. affine, 4 of S. kraussei, 8 of S. apuliae, 5 of S. ichnusae, 3 of S. carpocapsae, 1 of S. vulcanicum, 3 of Steinernema 'isolate S.sp.MY7' of 'S. intermedium group' and 1 of S. arenarium. Steinernematids are more widespread than heterorhabditids and S. feltiae and H. bacteriophora are the most commonly encountered species. Sampling sites were grouped into 11 habitats: uncultivated land, orchard, field, sea coast, pinewood, broadleaf wood, grasslands, river and lake borders, caves, salt pan and moist zones; the soil texture of each site was defined and the preferences of habitat and soil texture of each species was assessed. Except for the two dominant species, S. feltiae and H. bacteriophora, EPN occurrence tends to be correlated with a specific vegetation habitat. Steinernema kraussei, H. downesi and H. megidis were collected only in Sicily and three of the species recently described - S. apuliae, S. ichnusae and S. vulcanicum - are known only from Italy and seem to be endemic.

  20. Host suitability of soybean and corn genotypes to the root lesion caused by nematode under natural infestation conditions

    Directory of Open Access Journals (Sweden)

    Anderli Divina Ferreira Rios

    2016-04-01

    Full Text Available ABSTRACT: Among the nematode management strategies, genetic resistance is one of the most appropriate and desirable. However, resistant soybean and corn genotypes resistant to Pratylenchus brachyurus are not available up to the moment. The objective of this study was to evaluate the host suitability of 50 soybean and 38 corn genotypes to P. brachyurus under natural infestation. Soybean genotypes BRSGO Chapadões, BRSGO Paraíso, M-Soy 7211 RR, M-Soy 8008 RR, Emgopa 313 RR, M-Soy 8411, BRSGO Juliana RR, Emgopa 316 RR, BRSGO Luziânia RR and TMG 103 RR, and corn genotype Agromem 30A06 reduced the nematode population during the evaluation period.

  1. Successful application of entomopathogenic nematodes for the biological control of western corn rootworm larvae in Europe – a mini review

    Directory of Open Access Journals (Sweden)

    Toepfer, Stefan

    2014-02-01

    Full Text Available 10 years of joint efforts in research and development have led to a nematode-based biological control solution for one of the most destructive maize pests, the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae. Commercially mass-produced Heterorhabditis species of beneficial entomopathogenic nematodes are ready to use. They can be applied into the soil during sowing of maize for controlling the subsequently hatching larvae of D. virgifera virgifera thus preventing root feeding and damage to maize. Policy bodies, decision makers and farmers are advised to consider biological control as one of the alternatives to synthetic pesticides in maize production, and according to the EC Directive on the sustainable use of pesticides and implementation of integrated pest management.

  2. Checklist of free-living nematode species in the transitional environment of Lake Varano (Southern Italy)

    National Research Council Canada - National Science Library

    Semprucci, F; Balsamo, M

    2015-01-01

    ...–living nematode species in Lake Varano, Southern Adriatic Sea, Italy. The nematode community was mainly composed of species typical of fine sediments that usually prevail in transitional environments (TE...

  3. Taxonomy, morphology and phylogenetics of coffee-associated root-lesion nematodes, Pratylenchus spp

    Science.gov (United States)

    Technical Abstract: Although lesion nematodes (Pratylenchus species) can reduce coffee yield worldwide, methods for their identification are often difficult to implement. This review summarizes the diagnostic morphological features for distinguishing the eight previously described lesion nematode sp...

  4. Plant and soil nematodes from Lokchao Yangoupokpi Wildlife Sanctuary, Manipur, India

    Directory of Open Access Journals (Sweden)

    N. Mohilal

    2009-03-01

    Full Text Available In the present study soil samples were collected from Lokchao Yangoupokpi Wildlife Sanctuary to investigate about what nematode species are associated with different plant hosts. This study shows rich nematode diversity in the sanctuary.

  5. Predation rates and prey selectivity in two predacious estuarine nematode species

    NARCIS (Netherlands)

    Moens, T.; Herman, P.M.J.; Verbeeck, L.; Steyaert, M.; Vincx, M.

    2000-01-01

    Enoploides longispiculosus and Adoncholaimus fuscus are representatives of nematode genera prominent in sediments of the North Sea and adjacent estuaries. Both are predatory nematodes, although predation is facultative in the latter. The present study investigates functional responses and prey

  6. Nematodes as bioindicators of soil degradation due to heavy metals.

    Science.gov (United States)

    Šalamún, Peter; Renčo, Marek; Kucanová, Eva; Brázová, Tímea; Papajová, Ingrid; Miklisová, Dana; Hanzelová, Vladimíra

    2012-11-01

    The effect of distance from a heavy metal pollution source on the soil nematode community was investigated on four sampling sites along an 4 km transect originating at the Kovohuty a.s. Krompachy (pollution source). The soil nematode communities were exposed to heavy metal influence directly and through soil properties changes. We quantified the relative effects of total and mobile fraction of metals (As, Cd, Cr, Cu, Pb, and Zn) on soil ecosystem using the nematode community structure (trophic and c-p groups,) and ecological indices (Richness of genera, H', MI2-5, etc.). Pollution effects on the community structure of soil free living nematodes was found to be the highest near the pollution source, with relatively low population density and domination of insensitive taxa. A decrease in heavy metals contents along the transect was linked with an increase in complexity of nematode community. The majority of used indices (MI2-5, SI, H') negatively correlated (P bioindication of contamination and could be used as an alternative to the common approaches based on chemical methods.

  7. Plant genes involved in harbouring symbiotic rhizobia or pathogenic nematodes.

    Science.gov (United States)

    Damiani, Isabelle; Baldacci-Cresp, Fabien; Hopkins, Julie; Andrio, Emilie; Balzergue, Sandrine; Lecomte, Philippe; Puppo, Alain; Abad, Pierre; Favery, Bruno; Hérouart, Didier

    2012-04-01

    The establishment and development of plant-microorganism interactions involve impressive transcriptomic reprogramming of target plant genes. The symbiont (Sinorhizobium meliloti) and the root knot-nematode pathogen (Meloidogyne incognita) induce the formation of new root organs, the nodule and the gall, respectively. Using laser-assisted microdissection, we specifically monitored, at the cell level, Medicago gene expression in nodule zone II cells, which are preparing to receive rhizobia, and in gall giant and surrounding cells, which play an essential role in nematode feeding and constitute the typical root swollen structure, respectively. We revealed an important reprogramming of hormone pathways and C1 metabolism in both interactions, which may play key roles in nodule and gall neoformation, rhizobia endocytosis and nematode feeding. Common functions targeted by rhizobia and nematodes were mainly down-regulated, whereas the specificity of the interaction appeared to involve up-regulated genes. Our transcriptomic results provide powerful datasets to unravel the mechanisms involved in the accommodation of rhizobia and root-knot nematodes. Moreover, they raise the question of host specificity and the evolution of plant infection mechanisms by a symbiont and a pathogen.

  8. Variation in the susceptibility of Drosophila to different entomopathogenic nematodes.

    Science.gov (United States)

    Peña, Jennifer M; Carrillo, Mayra A; Hallem, Elissa A

    2015-03-01

    Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.

  9. Nematode Chemotaxis: Gradual Turns, Sharp Turns, and Modulated Turn Angles

    Science.gov (United States)

    Patel, Amar; Padmanabhan, Venkat; Rumbaugh, Kendra; Vanapalli, Siva; Blawzdziewicz, Jerzy

    2013-03-01

    We examine strategies used by the soil-dwelling nematode Caenorhabditis Elegans for chemotaxis in complex environments. The proposed description is based on our recently developed piecewise-harmonic-curvature model of nematode locomotion [PLoS ONE, 7(7) e40121 (2012)], where random harmonic-curvature modes represent elementary locomotory movements. We show that the previously described gradual-turn and sharp-turn chemotaxis strategies can be unified in our model. The gradual-turn mechanism relies on crawling amplitude changes commensurate with the undulation frequency. The sharp-turn mechanism consists in modulation of the frequency of jumps to large-amplitude modes. We hypothesize that there exists a third strategy, where the nematode adjusts the variance of the amplitude distribution. Such adjustments result in a modulation of the magnitude of random turns, with smaller turns performed when the nematode moves toward the increasing chemoatractant concentration. Experiments are proposed to determine if the third strategy is present in the nematode behavior. This work was supported by NSF grant No. CBET 1059745.

  10. The collective motion of nematodes in a thin liquid layer

    CERN Document Server

    Gart, Sean; Jung, Sunghwan

    2010-01-01

    Many organisms live in confined fluidic environments such as the thin liquid layers on the skin of host organisms or in partially- saturated soil. We investigate the collective behaviour of nematodes in a thin liquid layer, which was first observed by Gray and Lissmann, [J. Exp. Biol. 41, 135 (1964)]. We show experimentally that nematodes confined by a thin liquid film come into contact and only separate again after some intervention. We attribute this collective motion to an attractive force between them arising from the surface tension of the layer and show that for nearby nematodes this force is typically stronger than the force that may be exerted by the nematodes' muscles. We believe this to be the first demonstration of the "Cheerios effect" acting on a living organism. However, we find that being grouped together does not significantly alter the body stroke and kinematic performance of the nematode: there are no statistically significant changes of the Strouhal number and the ratio of amplitude to wave...

  11. On the cultivation of free-living marine and estuarine nematodes

    OpenAIRE

    T. Moens; Vincx, M.

    1998-01-01

    Although a large body of literature exists on the systematics and ecology of free-living marine and brackish-water nematodes, key questions on the nature and magnitude of interactions between nematodes and other organisms in the benthos remain unanswered. Relatively few authors have investigated live nematodes in food web studies or in experiments dealing with the nematodes' response to a varying environment. It is mainly for the latter purpose that attempts have been made to maintain, rear a...

  12. Gastrointestinal nematode infections in sheep and goats in West Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Beriajaya

    2005-12-01

    Full Text Available These studies were carried out in three locations representing low, medium and high altitudes in West Java to determine the effects of season, climate, management, growth and mortality on nematode parasitism in sheep and goats. Basically, the animals in each location were divided into treated and untreated groups with anthelmintics. Animals were weighed and faecal samples were collected every 2 to 4 weeks. Haemonchus contortus and Trichostrongylus spp. were the predominant species of gastrointestinal nematodes recovered from faecal cultures. In low altitude areas, faecal egg counts dropped progressively throughout the dry season and rose again with the onset of the wet season. The proportion of H. contortus larvae decreased progressively throughout the dry season and increased with the onset of the wet season, however the opposite pattern occurred with proportions of larvae of Trichostrongylus spp. In medium altitude areas, there was no consistent pattern of rising or falling faecal egg counts associated with fluctuations in rainfall. In high altitude areas, there was a trend for egg counts to increase progressively after the onset of the wet season even faecal egg counts were below 1500 epg. After treated with anthelmintics, faecal egg counts were suppressed to only few eggs in two weeks and then rose again in four week later, however in animals received medicated phenothiazine, mean egg counts were maintained below 500 epg. Treated animals in medium areas maintained low egg counts until the end of the trial. Seasonal fluctuation in weight gain of sheep was observed in low areas. Treated animals had significantly lower mortality than untreated animals but the evidence that parasitism contributed to this mortality is persuasive. It was concluded that nematode parasites cause a significant loss of production in sheep during wet season in coastal regions and in areas of rainfall throughout the year.

  13. Microsatellites of the parasitic nematode Haemonchus contortus: polymorphism and linkage with a direct repeat

    NARCIS (Netherlands)

    Hoekstra, R.; Criado-Fornelio, A.; Fakkeldij, J.; Bergman, J.; Roos, M.H.

    1997-01-01

    To develop tools to analyse parasitic nematode population structures and the effects of selection pressure on the nematode population, we isolated and characterised 13 microsatellite markers of the nematode Haemonchus contortus. The density of CA/GT microsatellites, once in 575 kb, is lower than in

  14. Trapping of root-knot nematodes by the adhesive hyphae-forming fungus Arthrobotrys oligospora.

    NARCIS (Netherlands)

    den Belder, E.

    1994-01-01

    The present study addresses the ecology of a particular isolate of Arthrobotrys oligospora (CBS 289.82) in relation to its efficacy in controlling the root-knot nematode, Meloidogyne hapla.This isolate was selected because it differs from most nematode-trapping fungi in that it captures nematodes wi

  15. High-throughput sequencing of nematode communities from total soil DNA extractions

    DEFF Research Database (Denmark)

    Sapkota, Rumakanta; Nicolaisen, Mogens

    2015-01-01

    nematodes without the need for enrichment was developed. Using this strategy on DNA templates from a set of 22 agricultural soils, we obtained 64.4% sequences of nematode origin in total, whereas the remaining sequences were almost entirely from other metazoans. The nematode sequences were derived from...

  16. A SNARE-like protein and biotin are implicated in soybean cyst nematode virulence

    Science.gov (United States)

    Some phytoparasitic nematodes have the ability to infect and reproduce on plants that are normally considered resistant to nematode infection. Such nematodes are referred to as virulent and the mechanisms they use to evade or suppress host plant defenses are not well understood. Here, we report the ...

  17. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  18. Microbial ecology and nematode control in natural ecosystems. Building coherence between microbial ecology and molecular mechanisms

    NARCIS (Netherlands)

    Costa, S.R.; Putten, van der W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient

  19. Towards isolation of the tomato root-knot nematode resistance gene Mi via positional cloning.

    NARCIS (Netherlands)

    Daelen, van R.A.J.J.

    1995-01-01

    Root-knot nematodes of the genus Meloidogyne are severe pathogens of plants and worldwide they cause damage to many economically important crops like potato, rice, cotton, and tomato. So the control of nematodes and the protection of plants against nematode damage are matters of major concern. Some

  20. Microbial ecology and nematode control in natural ecosystems. Building coherence between microbial ecology and molecular mechanisms

    NARCIS (Netherlands)

    Costa, S.R.; Putten, van der W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient cyclin

  1. [Effect of agrochemicals and bio-control productions on soil nematode community dynamics].

    Science.gov (United States)

    Zhang, Wanmin; Duan, Yuxi; Chen, Lijie; Liang, Chen

    2002-05-01

    Dynamics of soil nematode communities amended with agrochemicals and bio-control preparations were investigated in a soybean field. The results showed that the frequency of plant non-parasitic nematodes were obviously higher in soil amended with bio-control preparations (Doufeng 1) than with urea and herbicide, however, that of plant parasitic nematodes exhibited an inverse trend.

  2. Small-molecule pheromones and hormones controlling nematode development.

    Science.gov (United States)

    Butcher, Rebecca A

    2017-05-17

    The existence of small-molecule signals that influence development in Caenorhabditis elegans has been known for several decades, but only in recent years have the chemical structures of several of these signals been established. The identification of these signals has enabled connections to be made between these small molecules and fundamental signaling pathways in C. elegans that influence not only development but also metabolism, fertility, and lifespan. Spurred by these important discoveries and aided by recent advances in comparative metabolomics and NMR spectroscopy, the field of nematode chemistry has the potential to expand dramatically in the coming years. This Perspective will focus on small-molecule pheromones and hormones that influence developmental events in the nematode life cycle (ascarosides, dafachronic acids, and nemamides), will cover more recent work regarding the biosynthesis of these signals, and will explore how the discovery of these signals is transforming our understanding of nematode development and physiology.

  3. Extraintestinal nematode infections of red foxes (Vulpes vulpes) in Hungary.

    Science.gov (United States)

    Sréter, T; Széll, Z; Marucci, G; Pozio, E; Varga, I

    2003-08-14

    A survey was carried out to investigate the prevalence and worm burden of extraintestinal nematodes in 100 red foxes (Vulpes vulpes) of Hungary. The overall prevalence of nematode infections of the respiratory tract was 76%. Eucoleus aerophilus (Capillaria aerophila) was the predominant species (66%), followed by Crenosoma vulpis (24%), Eucoleus (Capillaria) böhmi (8%) and Angiostrongylus vasorum (5%). Pearsonema (Capillaria) plica was found in 52% of the urinary bladders. In 3% of the foxes, Trichinella britovi was present in muscle samples. The high prevalence of lungworms and P. plica and the fox colonisation in urban areas may enhance the prevalence of these nematode infections in domestic dogs and cats, and the flow of T. britovi from the sylvatic cycle to the domestic cycle, enhancing the risk of infections in humans.

  4. Nematodes of elasmobranch fishes from the southern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Knoff

    2001-01-01

    Full Text Available New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S. pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  5. The development of RNA interference (RNAi) in gastrointestinal nematodes.

    Science.gov (United States)

    Selkirk, Murray E; Huang, Stanley C; Knox, David P; Britton, Collette

    2012-04-01

    Despite the utility of RNAi for defining gene function in Caenorhabditis elegans and early successes reported in parasitic nematodes, RNAi has proven to be stubbornly inconsistent or ineffective in the animal parasitic nematodes examined to date. Here, we summarise some of our experiences with RNAi in parasitic nematodes affecting animals and discuss the available data in the context of our own unpublished work, taking account of mode of delivery, larval activation, site of gene transcription and the presence/absence of essential RNAi pathway genes as defined by comparisons to C. elegans. We discuss future directions briefly including the evaluation of nanoparticles as a means to enhance delivery of interfering RNA to the target worm tissue.

  6. Mechanisms Involved in Nematode Control by Endophytic Fungi.

    Science.gov (United States)

    Schouten, Alexander

    2016-08-04

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood but most likely multifactorial. This knowledge gap obstructs the progress regarding the development of endophytes or endophyte-derived constituents into biocontrol agents. In part, this may be caused by the fact that endophytic fungi form a rather heterogeneous group. By combining the knowledge of the currently characterized antagonistic endophytic fungi and their effects on nematode behavior and biology with the knowledge of microbial competition and induced plant defenses, the various mechanisms by which this nematode antagonism operates or may operate are discussed. Now that new technologies are becoming available and more accessible, the currently unresolved mechanisms can be studied in greater detail than ever before.

  7. Efficacy of extracts of immature mango on ovine gastrointestinal nematodes.

    Science.gov (United States)

    Nery, Patrícia S; Nogueira, Flávia A; Oliveira, Neide J F; Martins, Ernane R; Duarte, Eduardo R

    2012-12-01

    The principal health problem in small ruminants is helminthiasis and the rapid development of nematode resistance to anthelminthics has limited the success of control in several countries, stimulating the search for alternatives. In this study, extracts of immature fruits of the mango Mangifera indica L. var Ubá were evaluated for inhibition of larval development and fecal egg count reduction in sheep naturally infected with gastrointestinal nematodes. In the phytochemical analyses, tannins and flavonoids were the metabolites identified. Aqueous extracts of immature fruits at 100 mg ml(-1) showed 100 % inhibition of larval development. The LC(90) of the extract was 35.9 mg ml(-1) and the in vivo anthelminthic efficacy at 0.740 g kg(-1) (BW, orally) was 53 %. The identification of larvae showed that 99.8 % were Haemonchus spp. In vitro and in vivo results indicate that this fruit could assist ovine nematode control.

  8. Caenorhabditis elegans: A Genetic Guide to Parasitic Nematode Biology.

    Science.gov (United States)

    Bird, D M; Opperman, C H

    1998-09-01

    The advent of parasite genome sequencing projects, as well as an increase in biology-directed gene discovery, promises to reveal genes encoding many of the key molecules required for nematode-host interactions. However, distinguishing parasitism genes from those merely required for nematode viability remains a substantial challenge. Although this will ultimately require a functional test in the host or parasite, the free-living nematode Caenorhabditis elegans can be exploited as a heterologous system to determine function of candidate parasitism genes. Studies of C. elegans also have revealed genetic networks, such as the dauer pathway, that may also be important adaptations for parasitism. As a more directed means of identifying parasitism traits, we developed classical genetics for Heterodera glycines and have used this approach to map genes conferring host resistance-breaking phenotypes. It is likely that the C. elegans and H. glycines genomes will be at least partially syntenic, thus permitting predictive physical mapping of H. glycines genes of interest.

  9. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation.

    Science.gov (United States)

    Shapiro-Ilan, David I; Hazir, Selcuk; Lete, Luis

    2015-09-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  10. Frequency of cattle farms with ivermectin resistant gastrointestinal nematodes in Veracruz, Mexico.

    Science.gov (United States)

    Alonso-Díaz, M A; Arnaud-Ochoa, R A; Becerra-Nava, R; Torres-Acosta, J F J; Rodriguez-Vivas, R I; Quiroz-Romero, R H

    2015-09-15

    This study reports the percentage of cattle farms with ivermectin (IVM) resistant gastrointestinal nematodes (GINs) in Veracruz, Mexico, and identifies the GIN genera involved in the resistances. It also describes management practices of anthelmintic (AH) use on the surveyed farms. Twenty-one farms were assessed by means of the faecal egg count reduction test using the McMaster technique. Only two farms had GIN populations susceptible to IVM (9.5%). The proportion of farms with IVM resistant GIN was 71.4% (15/21). Seven of these farms had less than 80% egg count reductions. Haemonchus and Cooperia were the genera most commonly found in the resistant populations, followed by Oesophagostomum. Inappropriate AH treatment practices were identified from the completed questionnaires. Further management practices such as selective treatment and quarantine treatments are proposed to further reduce the spread of IVM resistance between farms.

  11. Studies onPaecilomyces marquandii from nematode suppressive chinampa soils.

    Science.gov (United States)

    Marban-Mendoza, N; Garcia-E, R; Dicklow, M B; Zuckerman, B M

    1992-05-01

    Two applications of isolates ofPaecilomyces marquandii from suppressive chinampa soils or P. lilacinus from Peru, fungi that parasitize nematode eggs, generally gave better control of tomato root-knot due toMeloidogyne incognita than did a single application. The effects on root galling by each of thePaecilomyces isolates varied between experiments; however, the ovicidal potential of the three isolates did not differ significantly. Proteins specific for each of the isolates were demonstrated by SDS gel electrophoresis. The results indicate thatP. marquandii is one of the natural soil organisms that contribute to nematode suppression in the chinampa agricultural soils.

  12. An evolutionary perspective on gastrointestinal nematodes of sheep.

    Science.gov (United States)

    Stear, M J; Singleton, D; Matthews, L

    2011-06-01

    The purpose of this paper was to discuss from an evolutionary perspective the interaction between domestic sheep (Ovis aries) and their gastrointestinal nematodes. Although evolution is the central theme of biology, there has been little attempt to consider how evolutionary forces have shaped and continue to shape the relationships between domestic animals and their parasite community. Mathematical modelling of the host-parasite relationship indicated that the system is remarkably robust to perturbations in its parameters. This robustness may be a consequence of the long coevolution of host and parasites. Although nematodes can potentially evolve faster than the host, coevolution is not dominated by the parasite and there are several examples where breeds of cattle or sheep have evolved high levels of resistance to disease. Coevolution is a more equal partnership between host and nematode than is commonly assumed. Coevolution between parasites and the host immune system is often described as an arms race where both host immune response genes and parasite proteins evolve rapidly in response to each other. However, initial results indicate that nematode antigens are not evolving rapidly; the arms race between the immune system and nematodes, if it exists, is happening very slowly. Fisher's fundamental theorem of natural selection states that genes with positive effects on fitness will be fixed by natural selection. Consequently, heritable variation in fitness traits is expected to be low. Contrary to this argument, there is considerable genetic variation in resistance to nematode infection. In particular, the heritabilities of nematode-specific IgA and IgE activity are moderate to high. The reasons for this apparent violation of the fundamental theorem of natural selection are not clear but several possible explanations are explored. Faecal nematode egg counts increase at the beginning of the grazing season - a phenomenon known as the periparturient rise. This

  13. Root - knot nematodes on summer vegetables in North Tunisia

    Directory of Open Access Journals (Sweden)

    Moens, M.

    1985-01-01

    Full Text Available The influence of different factors on the root-knot nematode infestation and on the yield of tomato have been examined : date of planting, cultivar choice, rotation scheme and soil disinfestation. It was found that the earliest planting date gave the highest yield but also the most severe root galling on susceptible tomato cultivars. A cropping sequence where wheat is alternated with tomatoes was not sufficient for reducing root-knot nematode population to a level permitting the cropping of a susceptible tomato cultivar. Long rotations with non host crops should be used. Soil treatment with certain nematicides significantly reduced the root galling and improved the yield.

  14. A Simple Method to Measure Nematodes' Propulsive Thrust and the Nematode Ratchet.

    Science.gov (United States)

    Bau, Haim; Yuan, Jinzhou; Raizen, David

    2015-11-01

    Since the propulsive thrust of micro organisms provides a more sensitive indicator of the animal's health and response to drugs than motility, a simple, high throughput, direct measurement of the thrust is desired. Taking advantage of the nematode C. elegans being heavier than water, we devised a simple method to determine the propulsive thrust of the animals by monitoring their velocity when swimming along an inclined plane. We find that the swimming velocity is a linear function of the sin of the inclination angle. This method allows us to determine, among other things, the animas' propulsive thrust as a function of genotype, drugs, and age. Furthermore, taking advantage of the animals' inability to swim over a stiff incline, we constructed a sawteeth ratchet-like track that restricts the animals to swim in a predetermined direction. This research was supported, in part, by NIH NIA Grant 5R03AG042690-02.

  15. A farmer friendly and economic IPM strategy to combat root-knot nematodes infesting lentil

    Directory of Open Access Journals (Sweden)

    Rose Rizvi

    2015-12-01

    Full Text Available An experiment was conducted to assess the effect of Rhizobium sp., waste tea leaves, eggshell powder, and composted cow dung manure on the root-knot nematode, Meloidogyne incognita, on lentil in Botany department AMU, Aligarh, India. When used alone, composted cow dung was better in reducing galling and nematode multiplication and improving lentil growth followed by eggshell powder, Rhizobium sp., and waste tea leaves. Significant result in the integrated management of M. incognita was obtained when Rhizobium sp. was used in combination with cow dung and eggshell powder (with or without waste tea leaves. Combined application of root nodule bacterium and organic wastes like waste tea leaves, eggshell, and cow dung may be suggested to the farmers/growers or related persons who are having great enthusiasm to establish a lentil production business. Application of these organic materials along with the root nodule bacteria may be helpful to foster soil ecosystem which has been a hot topic in the present scenario.

  16. Confirmation of root-knot nematode resistant gene Rmi1 using SSR markers

    Directory of Open Access Journals (Sweden)

    Musarrat Ramzan

    2017-02-01

    Full Text Available Background: The Root Knot Nematode (RKN is a serious economic threat to various cultivated crops worldwide. It is a devastating pest of soybean and responsible to cause severe yield loss in Pakistan. The cultivation of resistant soybean varieties against this pest is the sustainable strategy to manage the heavy loss and increase yield. There is an utmost need to identify RKN resistant varieties of soybean against cultivated in Pakistan. The presented study is an attempt to identify and confirm the presence of resistant gene Rmi1 in soybean. Method: Molecular studies have been done using Simple Sequence Repeat (SSR marker system to identify resistant soybean varieties against Root Knot Nematode (RKN using fifteen (15 indigenous cultivars and four (4 US cultivars. DNA was isolated, purified, quantified and then used to employ various SSR markers. The amplified product is observed using gel documentation system after electrophoresis. Results: Diagnostic SSR markers Satt-358 and Satt-492 have shown the presence of Rmi1 gene in all resistance carrying genotypes. Satt-358 amplified the fragment of 200 bp and Satt-492 generated 232 bp bands in all resistant genotypes. This study confirmed the Rmi gene locus (G248A-1 in all internationally confirmed resistant including six (6 native varieties. Conclusion: These investigations have identified six (6 resistant cultivars revealing the effective and informative sources that can be utilized in breeding programs for the selection of RKN resistance soybean genotypes in Pakistan.

  17. Insights into Adaptations to a Near-Obligate Nematode Endoparasitic Lifestyle from the Finished Genome of Drechmeria coniospora

    Science.gov (United States)

    Zhang, Liwen; Zhou, Zhengfu; Guo, Qiannan; Fokkens, Like; Miskei, Márton; Pócsi, István; Zhang, Wei; Chen, Ming; Wang, Lei; Sun, Yamin; Donzelli, Bruno G. G.; Gibson, Donna M.; Nelson, David R.; Luo, Jian-Guang; Rep, Martijn; Liu, Hang; Yang, Shengnan; Wang, Jing; Krasnoff, Stuart B.; Xu, Yuquan; Molnár, István; Lin, Min

    2016-01-01

    Nematophagous fungi employ three distinct predatory strategies: nematode trapping, parasitism of females and eggs, and endoparasitism. While endoparasites play key roles in controlling nematode populations in nature, their application for integrated pest management is hindered by the limited understanding of their biology. We present a comparative analysis of a high quality finished genome assembly of Drechmeria coniospora, a model endoparasitic nematophagous fungus, integrated with a transcriptomic study. Adaptation of D. coniospora to its almost completely obligate endoparasitic lifestyle led to the simplification of many orthologous gene families involved in the saprophytic trophic mode, while maintaining orthologs of most known fungal pathogen-host interaction proteins, stress response circuits and putative effectors of the small secreted protein type. The need to adhere to and penetrate the host cuticle led to a selective radiation of surface proteins and hydrolytic enzymes. Although the endoparasite has a simplified secondary metabolome, it produces a novel peptaibiotic family that shows antibacterial, antifungal and nematicidal activities. Our analyses emphasize the basic malleability of the D. coniospora genome: loss of genes advantageous for the saprophytic lifestyle; modulation of elements that its cohort species utilize for entomopathogenesis; and expansion of protein families necessary for the nematode endoparasitic lifestyle. PMID:26975455

  18. The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes.

    Science.gov (United States)

    Zheng, Jinshui; Peng, Donghai; Chen, Ling; Liu, Hualin; Chen, Feng; Xu, Mengci; Ju, Shouyong; Ruan, Lifang; Sun, Ming

    2016-07-27

    Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans, the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.

  19. Efficacy of commonly used anthelmintics: first report of multiple drug resistance in gastrointestinal nematodes of sheep in Trinidad.

    Science.gov (United States)

    George, N; Persad, K; Sagam, R; Offiah, V N; Adesiyun, A A; Harewood, W; Lambie, N; Basu, A K

    2011-12-29

    In Trinidad, small ruminant farms are semi-intensively managed under tropical conditions which support the development and survival of the infective stages of the helminths. Local farmers use anthelmintics to control gastrointestinal nematodes frequently. Frequent use of anthelmintics has the potential to select for populations of nematodes resistance to those chemicals. Hence, an attempt was made to study the efficacy of commonly used drugs on gastrointestinal nematodes of sheep. Three farms situated in different counties in Trinidad were selected. Sheep aged 6-15 months and not treated with anthelmintics for a minimum of six months previous and with faecal egg count (FEC)>150 eggs per gram were selected for study. They were allocated into 5 groups, each consisting 10 animals. The Group TA animals were treated once with albendazole (5mg/kg. b.wt.), group TF with fenbendazole (5mg/kg.b.wt.), group TI animals with ivermectin (200 μg/kg b.wt.), group TL with levamisol (7.5mg/kg b.wt.). The group NTC animals were not given any drug and served as control. The number of nematode eggs per gram of faeces from each animal was determined before treatment and at 14 days after treatment. The anthelmintic susceptibility to different drugs was detected by FECRT (in vivo) with EPG recorded at 14 day post-treatment. The data analysis using FECRT revealed that efficacy of albendazole (46-62%), fenbendazole (44-61%) and levamisol (53-81%) were reduced compared to ivermectin (95-97%). An attempt has also been made to find a suitable method for calculation of FECR (%).

  20. The activation and suppression of plant innate immunity by parasitic nematodes.

    Science.gov (United States)

    Goverse, Aska; Smant, Geert

    2014-01-01

    Plant-parasitic nematodes engage in prolonged and intimate relationships with their host plants, often involving complex alterations in host cell morphology and function. It is puzzling how nematodes can achieve this, seemingly without activating the innate immune system of their hosts. Secretions released by infective juvenile nematodes are thought to be crucial for host invasion, for nematode migration inside plants, and for feeding on host cells. In the past, much of the research focused on the manipulation of developmental pathways in host plants by plant-parasitic nematodes. However, recent findings demonstrate that plant-parasitic nematodes also deliver effectors into the apoplast and cytoplasm of host cells to suppress plant defense responses. In this review, we describe the current insights in the molecular and cellular mechanisms underlying the activation and suppression of host innate immunity by plant-parasitic nematodes along seven critical evolutionary and developmental transitions in plant parasitism.

  1. Breeding Soybeans for Resistance to Physiological Race 4 of Cyst Nematode

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-zheng; WANG Lan; YAN Qing-shang; ZHAO Rong-juan; CHEN Pin-san; LI Qiang

    2002-01-01

    Soybean cyst nematode causes serious damage to soybean production. In 1991, we started breeding studies on the resistance of soybeans to the cyst nematode. We found that near the Beijing area the dominant race of the cyst nematode was race 4. We made more than 50 combinations of cross. The best combination was Dan 8 × PI 437654 which resulted in marked segregation in plant height, pod habit, resistance to cyst nematode and maturity. We obtained many new soybean lines highly resistant to the cyst nematode through the pedigree method of selection, enlarging the number of plants of good combinations, alternative breeding in the North and in the South, and identification at an early generation. We now have released three soybean cultivars, Zhonghuang 12, Zhonghuang 13 and Zhonghuang 17 with moderate resistance to the cyst nematode in Beijing, Anhui, Tianjin and Northern China. In addition, we obtained many lines which were highly resistant to the cyst nematode.

  2. The dynamics of nematode infections of farmed ruminants

    NARCIS (Netherlands)

    Roberts, M.G.; Heesterbeek, J.A.P.

    1995-01-01

    In this paper the dynamics and control of nematode parasites of farmed ruminants are discussed via a qualitative analysis of a differential equation model. To achieve this a quantity, 'the basic reproduction quotient' (Q0), whose definition coincides with previous definitions of R0 for macroparasite

  3. Top 10 plant-parasitic nematodes in molecular plant pathology

    NARCIS (Netherlands)

    Jones, J.T.; Haegeman, A.; Danchin, E.G.J.; Gaur, H.S.; Helder, J.; Jones, M.G.K.; Kikuchi, T.; Manzanilla-López, R.; Palomares-Rius, J.E.; Wesemael, W.M.L.; Perry, R.N.

    2013-01-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a ‘top 10’ list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region

  4. Root-knot nematode resistant rootstocks for grafted watermelon

    Science.gov (United States)

    Rootstock lines of wild watermelon (Citrullus lanatus var. citroides) with resistance to root-knot nematodes (RKN) were developed by our team at the U.S. Vegetable Laboratory. Rootstock lines RKVL 301, RKVL 316, and RKVL 318 (RKVL = Root Knot Vegetable Laboratory) were compared to wild tinda (Praec...

  5. Nematode Infections Are Risk Factors for Staphylococcal Infection in Children

    Directory of Open Access Journals (Sweden)

    Sandra F Moreira-Silva

    2002-04-01

    Full Text Available Nematode infection may be a risk factor for pyogenic liver abscess in children and we hypothesized that the immunomodulation induced by those parasites would be a risk factor for any staphylococcal infection in children. The present study was designed to compare, within the same hospital, the frequency of intestinal nematodes and Toxocara infection in children with and without staphylococcal infections. From October 1997 to February 1998, 80 children with staphylococcal infection and 110 children with other diseases were submitted to fecal examination, serology for Toxocara sp., evaluation of plasma immunoglobulin levels, and eosinophil counts. Mean age, gender distribution, birthplace, and socioeconomic conditions did not differ significantly between the two groups. Frequency of intestinal nematodes and positive serology for Toxocara, were remarkably higher in children with staphylococcal infections than in the non-staphylococcal group. There was a significant correlation between intestinal nematodes or Toxocara infection and staphylococcal infection in children, reinforced by higher eosinophil counts and higher IgE levels in these children than in the control group. One possible explanation for this association would be the enhancement of bacterial infection by the immunomodulation induced by helminth infections, due to strong activation of the Th2 subset of lymphocytes by antigens from larvae and adult worms.

  6. Transposon associated markers for the parasitic nematode Haemonchus contortus

    NARCIS (Netherlands)

    Hoekstra, R.; Otsen, M.; Tibben, J.; Lenstra, J.A.; Roos, M.H.

    2000-01-01

    We have previously characterized a Tc1-like transposable element Hctc1, from the parasitic nematode Haemonchus contortus. Here we describe the genetic variation of Hctc1 insertion sites in H. contortus populations differing in geographical origin, resistance to chemotherapeutics and level of inbreed

  7. Phytoparasitic nematodes associated with three types of blueberries in arkansas.

    Science.gov (United States)

    Clark, J R; Robbins, R T

    1994-12-01

    Research and commercial blueberry plantings were sampled in October 1991 to determine the population densities and species of phytoparasitic nematodes associated with rabbiteye (Vaccinium ashei), southern highbush (Vaccinium sp.), and highbusb (V. corymbosum) blueberry cultivars and the sod middles between the blueberry rows. In the research planting at Clarksville, Arkansas, samples from the highbush cv. Bluecrop, the southern highbush cv. Cooper and Gulf Coast, and the sod middles had similar numbers of total vermiform phytoparasitic nematodes (125-451/250 cm(3) soil), whereas the samples from rabbiteye cv. Climax and Tifblue had significantly lower numbers (4/250 cm(3)). The major nematode species associated with blueberries and sod was Xiphinema americanum. In a research planting at Bald Knob, Arkansas, which contained Bluecrop and rabbiteye cultivars only, samples from Bluecrop and the sod had similar numbers (288 and 334/250 cm(3)), and the rabbiteye samples had significantly lower numbers (6-14/250 cm(3)). Xiphinema americanum was the major species found in the blueberry samples, whereas Mesocriconema ornata was the major species in the sod. Nematode population densities and species distribution in commercial rabbiteye plantings in nine counties in central and southwestern Arkansas varied greatly. The average population density for rabbiteye samples was 129/250 cm(3) and for sod was 577/250 cm(3). Weed infestations in the blueberry rows in the commercial plantings probably increased the population size and species distribution.

  8. Anthelmintic effects of forage chicory against parasitic nematodes in cattle

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Williams, Andrew; Thamsborg, Stig Milan;

    BACKGROUND: Chicory (Cichorium intybus) has potential as a natural anthelmintic in livestock, however evidence of efficacy against cattle nematodes is lacking. Here, we investigated anthelmintic effects of chicory in stabled calves. METHODS: Jersey male calves (2-4 months) were stratified by live...

  9. Putatively novel sources of resistance to soybean cyst nematode

    Science.gov (United States)

    Soybean cyst nematode (SCN) remains to be the most economically devastating endo-root parasite of soybean [Glycine max L. (Merrill)], in the USA and worldwide. Currently, two resistance loci, rhg1 and Rhg4 have been the main sources of resistance to SCN. Over 95% of soybean cultivars with SCN resist...

  10. IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt; Kania, Per Walter;

    Excretory/secretory (ES) products are molecules including various proteins produced by parasitic nematodes including larval A. simplex which is occurring in numerous marine fish hosts. The function of these substances and their effect on host physiology has not been fully described. The present...

  11. Inducible antibacterial defence in the plant parasitic nematode Meloidogyne artiellia.

    Science.gov (United States)

    Fanelli, Elena; Dileo, Caterina; Di Vito, Mauro; De Giorgi, Carla

    2008-04-01

    Animals and plants both respond rapidly to pathogens by inducing the expression of defence-related genes. Within this context, a prominent role has been assigned to the lysozyme. In the present study we isolated and carried out detailed analysis of the lysozyme gene in the plant nematode Meloidogyne artiellia. The expression of lysozyme was up-regulated following exposure of M. artiellia juveniles to the Gram-negative bacterium Serratia marcescens. On the other hand, when isolated eggs containing embryos at various developmental stages were challenged with bacteria, no increase in lysozyme expression was detected. Evidence of lysozyme expression regulation was obtained in the case of adult male and females worms collected from soil. The lysozyme gene was expressed solely in the nematode intestine and, as it is predicted to be secreted, may protect the nematode from microbial infections originating in the intestinal lumen or in the pseudocoelom. This paper demonstrates, to our knowledge for the first time, the immune response to infection in a plant parasitic nematode.

  12. 75 FR 11111 - Pale Cyst Nematode; Update of Quarantined Areas

    Science.gov (United States)

    2010-03-10

    ... Animal and Plant Health Inspection Service Pale Cyst Nematode; Update of Quarantined Areas AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Notice of changes to quarantined area. SUMMARY: We are advising the public that we have made changes to the area in the State of Idaho that...

  13. 77 FR 22185 - Golden Nematode; Removal of Regulated Areas

    Science.gov (United States)

    2012-04-13

    ... Inspection Service 7 CFR Part 301 Golden Nematode; Removal of Regulated Areas AGENCY: Animal and Plant Health... townships of Elba and Byron in Genesee County, NY, from the list of generally infested areas. Surveys have... regulation of these areas was no longer necessary. As a result of that action, all the areas in...

  14. Dietary copper sulfate for control of gastrointestinal nematodes in goats

    Science.gov (United States)

    Prevalence of anthelmintic resistance in goats has necessitated studies for alternative means of gastrointestinal nematode (GIN) control. The objective was to determine the effectiveness of dietary copper sulfate for control of GIN in meat goats. Naturally infected buck kids received 0 (LC), 78 (M...

  15. Herbal dewormer fails to control gastrointestinal nematodes in goats

    Science.gov (United States)

    Gastrointestinal nematode (GIN) parasitism is the most important disease of small ruminants. Control is usually based on the use of chemical anthelmintics (dewormers); but these are prohibited from use in organic livestock, and the effectiveness of chemical anthelmintics in conventional operations ...

  16. Field study on nematode resistance in Nelore-breed cattle

    NARCIS (Netherlands)

    Bricarello, P A; Zaros, L G; Coutinho, L L; Rocha, R A; Kooyman, F N J; De Vries, E; Gonçalves, J R S; Lima, L G; Pires, A V; Amarante, A F T

    2007-01-01

    The present study evaluated Nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. One hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from October 2003 to February 2004. Faecal and blood samples were colle

  17. Garlic exhibits lack of control over gastrointestinal nematodes in goats

    Science.gov (United States)

    Gastrointestinal nematodes (GIN) continue to hinder small ruminant production because of anthelmintic resistance and lack of effective products for GIN control in organic production. The objective of this study was to examine the effectiveness of a commercially available certified organic garlic pr...

  18. IN VITRO CULTURING OF THE PREDATORY SOIL NEMATODE CLARKUS PAPILLATUS

    Science.gov (United States)

    Clarkus papillatus is a widely distributed predatory soil nematode and is of interest in the study of soil ecology, yet very little information exists on its in vitro culturing. In this investigation, an artificial environment was created to maintain C. papillatus for multi-gener...

  19. Mitochondrial genome diversity in dagger and needle nematodes (Nematoda: Longidoridae)

    Science.gov (United States)

    Palomares-Rius, J. E.; Cantalapiedra-Navarrete, C.; Archidona-Yuste, A.; Blok, V. C.; Castillo, P.

    2017-01-01

    Dagger and needle nematodes included in the family Longidoridae (viz. Longidorus, Paralongidorus, and Xiphinema) are highly polyphagous plant-parasitic nematodes in wild and cultivated plants and some of them are plant-virus vectors (nepovirus). The mitochondrial (mt) genomes of the dagger and needle nematodes, Xiphinema rivesi, Xiphinema pachtaicum, Longidorus vineacola and Paralongidorus litoralis were sequenced in this study. The four circular mt genomes have an estimated size of 12.6, 12.5, 13.5 and 12.7 kb, respectively. Up to date, the mt genome of X. pachtaicum is the smallest genome found in Nematoda. The four mt genomes contain 12 protein-coding genes (viz. cox1-3, nad1-6, nad4L, atp6 and cob) and two ribosomal RNA genes (rrnL and rrnS), but the atp8 gene was not detected. These mt genomes showed a gene arrangement very different within the Longidoridae species sequenced, with the exception of very closely related species (X. americanum and X. rivesi). The sizes of non-coding regions in the Longidoridae nematodes were very small and were present in a few places in the mt genome. Phylogenetic analysis of all coding genes showed a closer relationship between Longidorus and Paralongidorus and different phylogenetic possibilities for the three Xiphinema species. PMID:28150734

  20. A serological approach to the identification of potato cyst nematodes.

    NARCIS (Netherlands)

    Schots, A.

    1988-01-01

    The potato cyst nematode species G.rostochiensis and G.pallida are a threat to the cultivation of potatoes. Their presence in the soil embodies a potential financial loss to the farmer either because of harvest reduction, or because of rejection of seed potatoes, and othe

  1. 75 FR 54592 - Pale Cyst Nematode; Update of Quarantined Areas

    Science.gov (United States)

    2010-09-08

    ... INFORMATION: Background The pale cyst nematode (PCN, Globodera pallida) is a major pest of potato crops in... some weeds. The PCN is thought to have originated in Peru and is now widely distributed in many potato-growing regions of the world. PCN infestations may be expressed as patches of poor growth. Affected...

  2. IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt; Kania, Per Walter;

    arylamidases, naphthol-AS-BI-phosphohydrolase and a-galactosidase activities were present in the ES solution. This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. Based on the notion that A. simplex ES-proteins may have an immune-depressive effect, it could also...

  3. Effect of entomopathogenic nematodes on Plectrodera scalator (Fabricius) (Coleoptera: Cerambycidae)

    Science.gov (United States)

    Declan J. Fallon; Leellen F. Solter; Leah S. Bauer; Deborah L. Miller; James R. Cate; Michael L. McManus

    2006-01-01

    Entomopathogenic nematodes were screened for efficacy against the cottonwood borer, Plectrodera scalator (Fabricius). Steinernema feltiae SN and S. carpocapsae All killed 58 and 50% of larvae, respectively, in Wlter paper bioassays but less than 10% in diet cup bioassays. S. glaseri NJ, S. riobrave TX, and H. indica MG-13 killed less than 10% of larvae in both assays....

  4. Nematodes for the biological control of the woodwasp, Sirex noctilio

    Science.gov (United States)

    Robin A. Bedding

    2007-01-01

    The tylenchid nematode Beddingia (Deladenus) siricidicola (Bedding) is by far the most important control agent of Sirex noctilio F., a major pest of pine plantations. It sterilizes female sirex, is density dependent, can achieve nearly 100 percent parasitism and, as a result of its complicated biology can be readily manipulated for sirex control. Bedding and Iede (2005...

  5. Foraging behavior and virulence of some entomopathogenic nematodes

    Directory of Open Access Journals (Sweden)

    Manana A. Lortkipanidze

    2016-06-01

    Full Text Available At present the biological control as a pest control technology is becoming more desirable. Biological formulations on basis of entomopathogenic nematodes are one of the effective means for the protection of agricultural and forest plants from harmful insects. Nowadays, the use of entomopathogenic nematodes as biological control agents is a key component in IPM system. The foraging strategies of entomopathogenic nematodes (EPNs vary between species. This variation is consistent with use of different foraging strategies between ambush, cruise and intermediate to find their host insects. In order to ambush prey, some species of EPNs nictate, or raise their bodies of the soil surface so they are better poised to attach passing insects, other species adopt a cruising strategy and rarely nictate. Some species adopt an intermediate strategy between ambush and cruise. We compared in laboratory the foraging strategies of the entomopathogenic nematode species: Steinernema carpocapsae, Heterorhabditis bacteriophora and the recently described species Steinernema tbilisiensis and assessed their virulence against mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae. The tests showed that S. tbilisiensis adopts both foraging strategies.

  6. Maintenance of genetic variation in automictic root-knot nematodes

    NARCIS (Netherlands)

    Van Der Beek, J. G. ( Hans); Punacker, Laas P.

    2008-01-01

    Differences in amplified fragment length polymorphisms (AFLP) between isolates and between mono-female lines of facultative automictic Meloidogyne hapla race A and obligate apomictic M incognita were determined to test the hypothesis that inverted meiosis occurs. DNA of the parthenogenetic nematode

  7. Mechanisms Involved in Nematode Control by Endophytic Fungi

    NARCIS (Netherlands)

    Schouten, Sander

    2016-01-01

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood

  8. Radiation sensitivity of pine wood nematodes in woodchips

    Energy Technology Data Exchange (ETDEWEB)

    Eichholz, G.G.; Bogdanov, A.A. (Georgia Inst. of Tech., Atlanta, GA (USA)); Dwinell, L.D. (Forest Service, Athens, GA (USA). Forestry Sciences Lab.)

    1991-01-01

    The radiation sensitivity of pine wood nematodes has been tested over a range of dose values with a cesium-137 irradiator. Lethal doses were found to lie in a range above 6-8 kGy, too high to make this an economically attractive means of deinfestation for commercial woodchips. (author).

  9. Top 10 plant-parasitic nematodes in molecular plant pathology

    NARCIS (Netherlands)

    Jones, J.T.; Haegeman, A.; Danchin, E.G.J.; Gaur, H.S.; Helder, J.; Jones, M.G.K.; Kikuchi, T.; Manzanilla-López, R.; Palomares-Rius, J.E.; Wesemael, W.M.L.; Perry, R.N.

    2013-01-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a ‘top 10’ list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region o

  10. Profiling nematode communities in unmanaged flowerbed and agricultural field soils in Japan by DNA barcode sequencing.

    Directory of Open Access Journals (Sweden)

    Hisashi Morise

    Full Text Available Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU rDNA fragments were directly amplified from each of 68 (flowerbed samples and 48 (field samples isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs, indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis.

  11. Understanding pine wilt disease: roles of the pine endophytic bacteria and of the bacteria carried by the disease-causing pinewood nematode.

    Science.gov (United States)

    Proença, Diogo N; Grass, Gregor; Morais, Paula V

    2017-04-01

    Pine wilt disease (PWD) is one of the most destructive diseases in trees of the genus Pinus and is responsible for environmental and economic losses around the world. The only known causal agent of the disease is the pinewood nematode (PWN) Bursaphelenchus xylophilus. Despite that, bacteria belonging to several different genera have been found associated with PWN and their roles in the development of PWD have been suggested. Molecular methodologies and the new era of genomics have revealed different perspectives to the problem, recognizing the manifold interactions between different organisms involved in the disease. Here, we reviewed the possible roles of nematode-carried bacteria in PWD, what could be the definition of this group of microorganisms and questioned their origin as possible endophytes, discussing their relation within the endophytic community of pine trees. The diversity of the nematode-carried bacteria and the diversity of pine tree endophytes, reported until now, is revised in detail in this review. What could signify a synergetic effect with PWN harming the plant, or what could equip bacteria with functions to control the presence of nematodes inside the tree, is outlined as two possible roles of the microbial community in the etiology of this disease. An emphasis is put on the potential revealed by the genomic data of isolated organisms in their potential activities as effective tools in PWD management. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Detrended-Fluctuation Analysis of Nematode Movement in Heterogeneous Environment

    Science.gov (United States)

    Hapca, S. M.; Gonzalez-Nieto, P.; Tarquis, A. M.

    2009-04-01

    We consider multifractal analysis in time scale to analyse the effect of structural heterogeneity on the movement of the slug-parasitic nematode, Phasmarhabditis hermaphrodita. The study involves image recording and analysis of nematode movement on a homogeneous layer of technical agar compared to movement of nematodes in a structurally heterogeneous environment that was created by adding sand particles to the plates of agar. The temporal scaling properties of the recorded trails were studied using a detrended fluctuation based method to capture the complex dynamic of movement data by comparing the multiscaling characteristics of nematode step lengths as affected by the different environments. A systematic analysis of the exponent of the structure function and the generalized Hurst exponent revealed that, while in homogeneous environment the movement was characterized by a long-range correlation with a Hurst exponent H(q) close to 1, varying little with respect to the order q of the fluctuation function, the impact of sand particle was to reduce the degree of persistence in the movement, the step lenghts being characterized by a smaller Hurst exponent, yet more variable. The results suggest that the presence of structural heterogeneity introduces a new bias into the movement, which plays an important role in complex environments where the nematode movement may be obstructed by soil particles. References Tarquis, A.M., Morato, M. C., Castellanos M.T., Perdigones A. 2009. Comparison of Structure Function and Detrended Fluctuation Analysis of Wind Time Series, Riv. Nuevo Cimento, in press. Gao, J., Cao, Y., Tung, W.-W., Hu J., 2007. Multiscale Analysis of Complex Times Series. Eds. John Wiley & Sons.

  13. Mermithid nematodes found in adult Anopheles from southeastern Senegal

    Directory of Open Access Journals (Sweden)

    Kobylinski Kevin C

    2012-06-01

    Full Text Available Abstract Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551 of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal

  14. Nematode succession during composting and the potential of the nematode community as an indicator of compost maturity

    NARCIS (Netherlands)

    Steel, H.; Peña, de la E.; Fonderie, P.; Willekens, K.; Borgonie, G.; Bert, W.

    2010-01-01

    One of the key issues in compost research is to assess when the compost has reached a mature stage. The maturity status of the compost determines the quality of the final soil amendment product. The nematode community occurring in a Controlled Microbial Composting (CMC) process was analyzed with the

  15. Differential in vitro pathogenicity of predatory fungi of the genus Monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of cattle

    Directory of Open Access Journals (Sweden)

    A.P.S. Gomes

    1999-01-01

    Full Text Available In vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus Monacrosporium (5 M. sinense isolates, 3 M. appendiculatum and 1 M. thaumasium isolate for a phytonematode (second stage juveniles from Meloidogyne incognita, race 3, a free-living nematode (Panagrellus spp, and two gastrointestinal parasitic nematodes of cattle (infective larvae of Cooperia punctata and Haemonchus placei. A suspension containing 2,000 nematodes from each species was added to Petri dishes containing fungi and grown on 2% water-agar medium at 25oC in the dark for up to 7 days. The dishes were examined every other day for 7 days and predation-free nematodes were counted. The results showed that the free-living nematodes, Panagrellus spp, were the most susceptible (P³98.5% viable. However, a variable susceptibility of the nematodes to different fungi was observed. This indicates that the use of predatory fungi for the environmental control of nematodes will be limited by the multiplicity of nematodes in the environment and their differential susceptibility to fungal isolates of the same genus.

  16. Anthelmintic resistance of nematode parasites of small ruminants in eastern Ethiopia: exploitation of refugia to restore anthelmintic efficacy.

    Science.gov (United States)

    Sissay, Menkir M; Asefa, Asmare; Uggla, Arvid; Waller, Peter J

    2006-02-18

    Faecal egg count reduction tests (FECRT) were conducted in May 2003 to determine the efficacy of anthelmintics used for treatment against nematode parasites in separately managed sheep and goat flocks at Alemaya University in eastern Ethiopia. These tests revealed high levels of anthelmintic resistance to albendazole, tetramisole, the combination of these two drugs, and to ivermectin in the goat flock (predominantly infected by Haemonchus contortus and Trichostrongylus spp.), whereas all drugs were highly efficacious in the sheep flock. A second FECRT confirmed these observations. Following this, a new management system was implemented on the goat flock for a period of 9 months (January-September 2004) in an attempt to restore the anthelmintic efficacy. This involved a combination of measures: eliminating the existing parasite infections in the goats, exclusion from the traditional goat pastures, and introducing communal grazing of the goats with the university sheep flock and livestock owned by neighbouring small-holder farmers. A second series of FECRTs (Tests 3 and 4) conducted 7 months after this change in management, showed high levels of efficacy to all three drugs (albendazole, tetramisole and ivermectin) in the goat flock. This is the first field study to demonstrate that anthelmintic efficacy in the control of nematode parasites of small ruminants can be restored by exploiting refugia.

  17. Assessment of nematode community structure as a bioindicator in river monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.C.; Chen, P.C. [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China); Tsay, T.T., E-mail: tttsay@nchu.edu.t [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China)

    2010-05-15

    Nematode communities from river water and sediments were assessed for the abundance, feeding types, maturity indices and nematode channel ratio (NCR). The sampling sites studied included different levels of pollution and contamination from agricultural, industrial and sewage sources. The nematode abundance found in the sediment samples was more than that in the water samples. The lowest nematode abundance in sediment samples and the lowest NCR in water samples were both found at the industrial pollution site. Water samples showed positive correlation between the NCR and river pollution index (RPI). Mean maturity indices in sediment samples were inversely correlated with RPI. The pollutant source determined the relationship between NCR and pollution level, while maturity index always showed negative correlation with pollutant level regardless of the pollutant sources. The nematode abundance and its community structure were both reliable bioindicators for monitoring long-term river pollution in both qualitative and quantitative aspects. - Nematode community structure in rivers is related to the contamination source and level.

  18. Integrated signaling networks in plant responses to sedentary endoparasitic nematodes: a perspective.

    Science.gov (United States)

    Li, Ruijuan; Rashotte, Aaron M; Singh, Narendra K; Weaver, David B; Lawrence, Kathy S; Locy, Robert D

    2015-01-01

    Sedentary plant endoparasitic nematodes can cause detrimental yield losses in crop plants making the study of detailed cellular, molecular, and whole plant responses to them a subject of importance. In response to invading nematodes and nematode-secreted effectors, plant susceptibility/resistance is mainly determined by the coordination of different signaling pathways including specific plant resistance genes or proteins, plant hormone synthesis and signaling pathways, as well as reactive oxygen signals that are generated in response to nematode attack. Crosstalk between various nematode resistance-related elements can be seen as an integrated signaling network regulated by transcription factors and small RNAs at the transcriptional, posttranscriptional, and/or translational levels. Ultimately, the outcome of this highly controlled signaling network determines the host plant susceptibility/resistance to nematodes.

  19. A novel ascaroside controls the parasitic life cycle of the entomopathogenic nematode Heterorhabditis bacteriophora.

    Science.gov (United States)

    Noguez, Jaime H; Conner, Elizabeth S; Zhou, Yue; Ciche, Todd A; Ragains, Justin R; Butcher, Rebecca A

    2012-06-15

    Entomopathogenic nematodes survive in the soil as stress-resistant infective juveniles that seek out and infect insect hosts. Upon sensing internal host cues, the infective juveniles regurgitate bacterial pathogens from their gut that ultimately kill the host. Inside the host, the nematode develops into a reproductive adult and multiplies until unknown cues trigger the accumulation of infective juveniles. Here, we show that the entomopathogenic nematode Heterorhabditis bacteriophora uses a small-molecule pheromone to control infective juvenile development. The pheromone is structurally related to the dauer pheromone ascarosides that the free-living nematode Caenorhabditis elegans uses to control its development. However, none of the C. elegans ascarosides are effective in H. bacteriophora, suggesting that there is a high degree of species specificity. Our report is the first to show that ascarosides are important regulators of development in a parasitic nematode species. An understanding of chemical signaling in parasitic nematodes may enable the development of chemical tools to control these species.

  20. How do the macrocyclic lactones kill filarial nematode larvae?

    Science.gov (United States)

    Wolstenholme, Adrian J; Maclean, Mary J; Coates, Ruby; McCoy, Ciaran J; Reaves, Barbara J

    2016-09-01

    The macrocyclic lactones (MLs) are one of the few classes of drug used in the control of the human filarial infections, onchocerciasis and lymphatic filariasis, and the only one used to prevent heartworm disease in dogs and cats. Despite their importance in preventing filarial diseases, the way in which the MLs work against these parasites is unclear. In vitro measurements of nematode motility have revealed a large discrepancy between the maximum plasma concentrations achieved after drug administration and the amounts required to paralyze worms. Recent evidence has shed new light on the likely functions of the ML target, glutamate-gated chloride channels, in filarial nematodes and supports the hypothesis that the rapid clearance of microfilariae that follows treatment involves the host immune system.

  1. Effects of Abiotic Environmental Factors on Soybean Cyst Nematode

    Institute of Scientific and Technical Information of China (English)

    DUAN Yu-xi; ZHENG Ya-nan; CHEN Li-jie; ZHOU Xiao-min; WANG Yuan-yuan; SUN Jing-shuang

    2009-01-01

    As a pest, in order to complete its life history and reproduces effectively, soybean cyst nematode (SCN) (Heterodera glycines Ichinche 1952) must adapt to various environments and conditions for long periods of evolution. The nematode is widely dispersed year after year. Controlling this pest requires understanding characters and adaptability of SCN.Effects of abiotic factors, such as temperature, soil humidity, agrotype, pH value, ions, plant exudates, agricultural chemical and cultivation systems on SCN, are reviewed in this paper. The results show that SCN is able to endure various environmental stresses, especially low temperature. Because of its special life history, cyst stage help SCN over winter,resistance of SCN to environmental stress is strong. A few studies have reported the mechanism of SCN environmental adaptability. We emphasized the importance of studying environmental adaptability of SCN, which would benefit the control of SCN by ecological means.

  2. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia

    OpenAIRE

    Henning, Tyler C.; Orr, John M.; Smith, Joshua D.; Arias, Jorge R.; Rasgon, Jason L.; Norris, Douglas E.

    2015-01-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations ...

  3. Transcriptome Analysis of Resistant and Susceptible Alfalfa Cultivars Infected With Root-Knot Nematode Meloidogyne incognita

    OpenAIRE

    Postnikova, Olga A.; Maria Hult; Jonathan Shao; Andrea Skantar; Nemchinov, Lev G.

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute...

  4. Introduction to Nematode Genome and Transcriptome Announcements in the Journal of Nematology.

    Science.gov (United States)

    Denver, Dee R; Ragsdale, Erik J; Thomas, W Kelley; Zasada, Inga A

    2017-06-01

    The Journal of Nematology now offers publication of Nematode Genome Announcements (NGA) and Nematode Transcriptome Announcements (NTA). These brief reports announce the sequencing and assembly of a nematode genome or transcriptome resource, along with basic technical information on DNA sequencing and bioinformatic methods used. This publishing initiative offers a new avenue to openly and concisely communicate the availability and relevance of genome and transcriptome sequence resources to the broader scientific community.

  5. Freeliving marine nematodes as a pollution indicator of Bohai Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A hierarchical diversity index--taxonomic distinctnessindex +, which was first defined by Warwick and Clark in 1998, wasemployed to evaluate the pollution status of the Bohai Sea withfreeliving marine nematodes. The result showed that the Bohai Bayand other coastal sampling sites might be affected by oil and gasproduction and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of thebenthos in these locations. And most offshore sampling sites in themiddle of the Bohai Sea were clear and unpolluted.

  6. Attraction of undulatory swimmers, such as nematodes, to surfaces

    Science.gov (United States)

    Yuan, Jinzhou; Raizen, David; Bau, Haim

    2014-11-01

    Nematodes play a significant role in the ecosystem; agriculture; human, animal, and plant disease; and medical research. The interactions between nematodes and surfaces may play an important role in nematodes' life cycle and ability to invade a host. We studied the effect of a surface on the dynamics of low-Reynolds number, undulating swimmers such as Caenorhabditis (C.) elegans -both wild type and touch-insensitive. The experiments demonstrated that swimmers located far from a surface selected randomly their direction of motion. In contrast, surface-proximate swimmers rotated towards, collided with, and swam along the surface for considerable time intervals, periodically contacting the surface with their anterior. Likewise, swimmers in a swarm were present at higher concentrations close to the surface. Both resistive force theory-based calculations and symmetry arguments predict that short range hydrodynamic torque, resulting from the interaction between the swimmer-induced flow field and the surface, rotate the swimmer towards the surface. We conclude that the surface attraction and following results from the interplay between short-range hydrodynamic and steric forces and is genotype-independent. The work was supported, in part, by NIH NIA 5R03AG042690-02 and NBIC NSF NSEC DMR08-32802.

  7. Prevalence and intensity of nematode parasites in Wisconsin ermine.

    Science.gov (United States)

    Dubay, Shelli; Buchholz, Matthew J; Lisiecki, Robert; Huspeni, Todd; Ginnett, Tim; Haen, Luke; Borsdorf, Phil

    2014-10-01

    In the midwestern United States, ermine ( Mustela erminea ) are economically important because they are legally harvested for pelts. Information on parasites of ermine is lacking, and the effects that nematode parasites have on body condition of ermine hosts are unknown. We identified Skrjabingylus nasicola and Filaroides martis in ermine trapped from 2007 to 2013 from 6 counties in Wisconsin. Small mammals, commonly consumed by ermine, serve as paratenic hosts for both parasites. Our goal was to identify how age and sex of ermine, along with year, influence nematode parasitism. We also investigated how infection affected body condition for male and female ermine using body mass standardized by length as an index of body condition. We commonly found S. nasicola and F. martis in male and female ermine, but both prevalence and intensity of infection were higher for males. Relative to juveniles (1 yr) male ermine did not exhibit significantly higher intensity or prevalence of either parasite. We found that body condition was not compromised by infection for either sex, and intensity of S. nasicola and prevalence of F. martis were highest during the 2010-2011 trapping season. Of the 6 yr studied, precipitation was highest during the summer before the 2010-2011 season, and increased precipitation can cause increases in populations of gastropod intermediate hosts. We think that several distinct natural history components, namely, mating structure, diet, and metabolic rate, influence nematode parasitism in ermine.

  8. Natural variation of outcrossing in the hermaphroditic nematode Pristionchus pacificus

    Directory of Open Access Journals (Sweden)

    Click Arielle

    2009-04-01

    Full Text Available Abstract Background Evolution of selfing can be associated with an increase in fixation of deleterious mutations, which in certain conditions can lead to species extinction. In nematodes, a few species evolved self-fertilization independently, making them excellent model systems to study the evolutionary consequences of this type of mating system. Results Here we determine various parameters that influence outcrossing in the hermaphroditic nematode Pristionchus pacificus and compare them to the better known Caenorhabditis elegans. These nematode species are distinct in terms of genetic diversity, which could be explained by differences in outcrossing rates. We find that, similarly to C. elegans, P. pacificus males are generated at low frequencies from self-fertilizing hermaphrodites and are relatively poor mating partners. Furthermore, crosses between different isolates reveal that hybrids have lower brood sizes than the pure strains, which is a sign of outbreeding depression. In contrast to C. elegans, P. pacificus has lower brood sizes and the male X-bearing sperm is able to outcompete the X-nullo sperm. Conclusion The results indicate that there is no evidence of any selection acting very strongly on P. pacificus males.

  9. A New Methodology for Evaluation of Nematode Viability

    Directory of Open Access Journals (Sweden)

    Sebastião Rodrigo Ferreira

    2015-01-01

    Full Text Available Nematodes infections are responsible for debilitating conditions and economic losses in domestic animals as well as livestock and are considered an important public health problem due to the high prevalence in humans. The nematode resistance for drugs has been reported for livestock, highlighting the importance for development of new anthelmintic compounds. The aim of the current study was to apply and compare fluorimetric techniques using Sytox and propidium iodide for evaluating the viability of C. elegans larvae after treatment with anthelmintic drugs. These fluorescent markers were efficient to stain larvae treated with ivermectin and albendazole sulfoxide. We observed that densitometric values were proportional to the concentration of dead larvae stained with both markers. Furthermore, data on motility test presented an inverse correlation with fluorimetric data when ivermectin was used. Our results showed that lower concentrations of drugs were effective to interfere in the processes of cellular transport while higher drugs concentrations were necessary in order to result in any damage to cell integrity. The methodology described in this work might be useful for studies that aim to evaluate the viability of nematodes, particularly for testing of new anthelminthic compounds using an easy, economic, reproducible, and no time-consuming technique.

  10. Origanum vulgare (Lamiaceae OVICIDAL POTENTIAL ON GASTROINTESTINAL NEMATODES OF CATTLE

    Directory of Open Access Journals (Sweden)

    Luciana Laitano Dias de Castro

    2013-12-01

    Full Text Available Due to anthelmintic resistance in nematodes, several research studies have been developed seeking control alternatives to these parasites. This study evaluated the in vitro action of Origanum vulgare on gastrointestinal nematode eggs of cattle. In order to evaluate the ability to inhibit egg hatch, different dried leaves extracts of this plant were tested, such as dye, hydroalcoholic and aqueous extracts at concentrations varying from 0.62 to 80 mg/mL. Each assay was accompanied by control containing levamisole hydrochloride (0.2 mg/mL, distilled water and 70 ºGL grain alcohol at the same concentration of the extracts. Test results showed that the different O. vulgare extracts inhibited egg hatch of cattle gastrointestinal nematodes at a percentage that varied from 8.8 to 100%; dye and hydroalcoholic extract were the most promising inhibitors. In view of this ovicidal property, O. vulgare may be an important source of viable antiparasitic compounds for nematodiosis control in ruminants.

  11. Analysis of nematode mechanics by piezoresistive displacement clamp.

    Science.gov (United States)

    Park, Sung-Jin; Goodman, Miriam B; Pruitt, Beth L

    2007-10-30

    Studying animal mechanics is critical for understanding how signals in the neuromuscular system give rise to behavior and how force-sensing organs and sensory neurons work. Few techniques exist to provide forces and displacements appropriate for such studies. To address this technological gap, we developed a metrology using piezoresistive cantilevers as force-displacement sensors coupled to a feedback system to apply and maintain defined load profiles to micrometer-scale animals. We show that this system can deliver forces between 10(-8) and 10(-3) N across distances of up to 100 mum with a resolution of 12 nN between 0.1 Hz and 100 kHz. We use this new metrology to show that force-displacement curves of wild-type nematodes (Caenorhabditis elegans) are linear. Because nematodes have approximately cylindrical bodies, this finding demonstrates that nematode body mechanics can be modeled as a cylindrical shell under pressure. Little is known about the relative importance of hydrostatic pressure and shell mechanics, however. We show that dissipating pressure by cuticle puncture or decreasing it by hyperosmotic shock has only a modest effect on stiffness, whereas defects in the dpy-5 and lon-2 genes, which alter body shape and cuticle proteins, decrease and increase stiffness by 25% and 50%, respectively. This initial analysis of C. elegans body mechanics suggests that shell mechanics dominates stiffness and is a first step in understanding how body mechanics affect locomotion and force sensing.

  12. Sex-specific mating pheromones in the nematode Panagrellus redivivus.

    Science.gov (United States)

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H; Dossey, Aaron T; Yim, Joshua J; Ajredini, Ramadan; Kolawa, Adam A; Kaplan, Fatma; Alborn, Hans T; Teal, Peter E A; Schroeder, Frank C; Sternberg, Paul W; Edison, Arthur S

    2012-12-18

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.

  13. Pathogenicity of Four Entomopathogenic Nematodes Species to G. mellonella Larvae

    Directory of Open Access Journals (Sweden)

    Pavel Hyrsl

    2011-06-01

    Full Text Available Entomopathogenic nematodes (EPNs of the genera Heterorhabditis and Steinernema are obligate and lethal insect parasites. In last decade they are widely used as biological control agents for pest insects of commercial crops, therefore research in this area is directly linked to agriculture. In this study, the pathogenicity of four nematode species (Heterorhabditis bacteriophora, Steinernema glaseri, Steinernema scarabaei and Steinernema feltiae was tested against Galleria mellonella larvae. Infective stage of EPNs together with their symbiotic bacteria kills insect host within 48 hours. The results show that mortality of insect host correlates with number of invaded infective juveniles (IJs. The invasion process is very fast, IJs enters insect host within a few hours. The importance of digestive tract as entering site was clearly demonstrated, larvae with empty gut are much more sensitive to nematode infection. Nemato-bacterial complex is very effective system overcoming insect immune defences. Encapsulation as the only one cellular reaction is activated, but in very low rate and was detected only during infection of H. bacteriophora.

  14. Soil nematode responses to increases in nitrogen deposition and precipitation in a temperate forest.

    Science.gov (United States)

    Sun, Xiaoming; Zhang, Xiaoke; Zhang, Shixiu; Dai, Guanhua; Han, Shijie; Liang, Wenju

    2013-01-01

    The environmental changes arising from nitrogen (N) deposition and precipitation influence soil ecological processes in forest ecosystems. However, the corresponding effects of environmental changes on soil biota are poorly known. Soil nematodes are the important bioindicator of soil environmental change, and their responses play a key role in the feedbacks of terrestrial ecosystems to climate change. Therefore, to explore the responsive mechanisms of soil biota to N deposition and precipitation, soil nematode communities were studied after 3 years of environmental changes by water and/or N addition in a temperate forest of Changbai Mountain, Northeast China. The results showed that water combined with N addition treatment decreased the total nematode abundance in the organic horizon (O), while the opposite trend was found in the mineral horizon (A). Significant reductions in the abundances of fungivores, plant-parasites and omnivores-predators were also found in the water combined with N addition treatment. The significant effect of water interacted with N on the total nematode abundance and trophic groups indicated that the impacts of N on soil nematode communities were mediated by water availability. The synergistic effect of precipitation and N deposition on soil nematode communities was stronger than each effect alone. Structural equation modeling suggested water and N additions had direct effects on soil nematode communities. The feedback of soil nematodes to water and nitrogen addition was highly sensitive and our results indicate that minimal variations in soil properties such as those caused by climate changes can lead to severe changes in soil nematode communities.

  15. Nematode abundance at the oxygen minimum zone in the Arabian Sea

    Science.gov (United States)

    Cook, Adam A.; Lambshead, P. John D.; Hawkins, Lawrence E.; Mitchell, Nicola; Levin, Lisa A.

    2000-01-01

    This paper supports the hypothesis that low oxygen does not influence deep-sea nematode abundance by investigating an oxygen minimum zone (OMZ) on the Oman slope in the Arabian Sea. Correlation with a number of environmental variables indicated that food quality (measured as the hydrogen index) rather than oxygen was the major predictor of nematode abundance. Nematode abundance was also positively correlated with abundance of total macrofauna, annelids, spionid polychaetes and macrofaunal tube builders. Comparison with published data showed Arabian Sea nematode abundance to be similar to that of the Porcupine Seabight and Bay of Biscay regions of the northeast Atlantic, which also receive significant quantities of phytodetritus but have no OMZ.

  16. Infestation of natural populations of earthworm cocoons by rhabditid and cephalobid nematodes

    DEFF Research Database (Denmark)

    Kraglund, HO; Ekelund, Flemming

    2002-01-01

    Nematodes infested 13 of 100 earthworm cocoons from a compost pile and 17 of 197 cocoons from a permanent pasture soil. Between one and 2000 nematodes were found within the infested cocoons. All nematodes found in cocoons from the compost pile belonged to the genus Rhabditis, while Rhabditis spp....... as well as members of Cephalobidae infested earthworm cocoons in the pasture soil. In cultures established from cocoons found in the pasture soil, at least five different types of nematodes belonging to the family Cephalobidae were found. Acrobeloides nanus was found in six cocoons, Cephalobus persegnis...

  17. Filarial Nematode Infection in Ixodes scapularis Ticks Collected from Southern Connecticut

    Directory of Open Access Journals (Sweden)

    Pabbati Namrata

    2014-05-01

    Full Text Available It was recently demonstrated that the lone star tick Amblyomma americanum could harbor filarial nematodes within the genus Acanthocheilonema. In this study, Ixodes scapularis (deer ticks collected from Southern Connecticut were evaluated for their potential to harbor filarial nematodes. Non-engorged nymphal and adult stage Ixodes scapularis ticks were collected in Southern Connecticut using the standard drag method. In situ hybridization with filarial nematode specific sequences demonstrated the presence of filarial nematodes in Ixodes ticks. Filarial nematode specific DNA sequences were amplified and confirmed by direct sequencing in Ixodes nymphal and adult ticks using either general filarial nematode or Onchocercidae family specific PCR primers. Phylogenetic analysis of the 12S rDNA gene sequence indicated that the filarial nematode infecting Ixodes scapularis ticks is most closely related to the species found in Amblyoma americanum ticks and belongs to the genus of Acanthocheilonema. Our data also demonstrated that infection rate of these filarial nematode in Ixodes ticks is relatively high (about 22% and 30% in nymphal and adult Ixodes ticks, respectively. In summary, the results from our studies demonstrated that filarial nematode infection was found in Ixodes ticks similar to what has been found in Amblyomma americanum ticks.

  18. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia.

    Science.gov (United States)

    Henning, Tyler C; Orr, John M; Smith, Joshua D; Arias, Jorge R; Rasgon, Jason L; Norris, Douglas E

    2016-03-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations in Maryland as well as recently identified parasites in Ixodes scapularis from southern Connecticut. Further study is warranted to visually confirm the presence of these nematodes, characterize their distribution, and determine if these ticks are intermediate hosts.

  19. The Effect of Crop Rotation on Soil Nematode Community Composition in a Greenhouse

    Institute of Scientific and Technical Information of China (English)

    Jingwen LU; Wei SHENG; Qian YU; Zijing CHEN; Qiang XU; Qian WANG; Linlin DONG

    2015-01-01

    Objective] The aim was to identify changes in a nematode community in response to crop rotation and to determine the appropriate catch crop for a green-house. [Method] The experiment was carried out in a typical 6-year-old greenhouse, in which cucumber crops were cultivated twice each year (in spring and autumn), and catch crops were planted in summer. The total number of nematodes was counted and nematode community indices were calculated after col ecting soil sam-ples in different stages. [Result] Total nematode abundance was decreased in the soils of catch crop in contrast with former crops (cucumber crops). The abundance of the nematode community was reduced in the treatment of crop rotation compared to the soils of catch crop. ln addition, the number of nematode taxa was significant-ly reduced by the treatment of crown daisy compared to the treatments of fol owing crops. Crop rotation regulated the functional composition of the nematode community by increasing the omnivores-predators functional group and decreasing the relative abundance of root herbivores. [Conclusion] These results indicate that crop rotation affects the nematode community in abundance, diversity and functional composition of the nematode community and crown daisy can be served as the most appropri-ate catch crop in the greenhouse.

  20. Control of Root-knot Nematodes on Tomato in Stone Wool Substrate with Biological Nematicides

    Science.gov (United States)

    López-Pérez, Jose Antonio; Edwards, Scott

    2011-01-01

    The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction. PMID:22791920

  1. Mutual influences in growth and reproduction between pine wood nematode Bursaphelenchus xylophilus and bacteria it carries

    Institute of Scientific and Technical Information of China (English)

    ZHAO Boguang; LIU Yutao; LIN Feng

    2006-01-01

    The interactions between pine wood nematode and three bacterium strains isolated from the nematode,Bursaphelenchus xylophilus,which are two strong pathogenic bacterium strains, Pseudomonas fluorescens GcMS-1A and Pseudomonas putida ZpB1-2A and a weak-pathogenic bacterium strain,Pantoea sp.ZM2C,were studied.The result showed that the strong-pathogenic GcM5-1A strain and ZpB 1-2A strain significantly increased fecundity,reproduction rate,and the body volume of the adult nematode.Meanwhile,pine wood nematodes significantly promoted reproduction of the two strong-pathogenic bacterium strains.However,the weak-pathogenic bacterium strain,ZM2C,completely inhibited reproduction of pine wood nematodes.Aseptic pine wood nematodes significantly inhibited reproduction of the strain ZM2C.The results indicated that mutualistic symbiosis exists between pine wood nematodes and the two pathogenic bacteria it carries.The phenomenon showed that the pathogenic bacteria carried by the nematode were not accidentally contaminated,but rather had existed as symbionts of the nematode with which it had coevoluted over a long period.The role of mutualistic symbiosis in the process of pine wilt disease was also discussed.

  2. Free-living nematodes in the freshwater food web: a review.

    Science.gov (United States)

    Majdi, Nabil; Traunspurger, Walter

    2015-03-01

    Free-living nematodes are well-recognized as an abundant and ubiquitous component of benthic communities in inland waters. Compelling evidence from soil and marine ecosystems has highlighted the importance of nematodes as trophic intermediaries between microbial production and higher trophic levels. However, the paucity of empirical evidence of their role in freshwater ecosystems has hampered their inclusion in our understanding of freshwater food web functioning. This literature survey provides an overview of research efforts in the field of freshwater nematode ecology and of the complex trophic interactions between free-living nematodes and microbes, other meiofauna, macro-invertebrates, and fishes. Based on an analysis of the relevant literature and an appreciation of the potential of emerging approaches for the evaluation of nematode trophic ecology, we point out research gaps and recommend relevant directions for further research. The latter include (i) interactions of nematodes with protozoans and fungi; (ii) nonconsumptive effects of nematodes on microbial activity and the effects of nematodes on associated key ecosystem processes (decomposition, primary production); and (iii) the feeding selectivity and intraspecific feeding variability of nematodes and their potential impacts on the structure of benthic communities.

  3. Control of root-knot nematodes on tomato in stone wool substrate with biological nematicides.

    Science.gov (United States)

    López-Pérez, Jose Antonio; Edwards, Scott; Ploeg, Antoon

    2011-06-01

    The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction.

  4. RNA-Seq reveals the molecular mechanism of trapping and killing of root-knot nematodes by nematode-trapping fungi.

    Science.gov (United States)

    Pandit, Ramesh; Patel, Reena; Patel, Namrata; Bhatt, Vaibhav; Joshi, Chaitanya; Singh, Pawan Kumar; Kunjadia, Anju

    2017-04-01

    Nematode-trapping fungi are well known for their inherent potential to trap and kill nematodes using specialized trapping devices. However, the molecular mechanisms underlying the trapping and subsequent processes are still unclear. Therefore, in this study, we examined differential genes expression in two nematode-trapping fungi after baiting with nematode extracts. In Arthrobotrys conoides, 809 transcripts associated with diverse functions such as signal transduction, morphogenesis, stress response and peroxisomal proteins, proteases, chitinases and genes involved in the host-pathogen interaction showed differential expression with fold change (>±1.5 fold) in the presence of nematode extract with FDR (p-value < 0.001). G-proteins and mitogen activated protein kinases are considered crucial for signal transduction mechanism. Results of qRT-PCR of 20 genes further validated the sequencing data. Further, variations in gene expression among Duddingtonia flagrans and A. conoides showed septicity of nematode-trapping fungi for its host. The findings illustrate the molecular mechanism of fungal parasitism in A. conoides which may be helpful in developing a potential biocontrol agent against parasitic nematodes.

  5. Bioinformatic prediction of arthropod/nematode-like peptides in non-arthropod, non-nematode members of the Ecdysozoa.

    Science.gov (United States)

    Christie, Andrew E; Nolan, Daniel H; Garcia, Zachery A; McCoole, Matthew D; Harmon, Sarah M; Congdon-Jones, Benjamin; Ohno, Paul; Hartline, Niko; Congdon, Clare Bates; Baer, Kevin N; Lenz, Petra H

    2011-02-01

    The Onychophora, Priapulida and Tardigrada, along with the Arthropoda, Nematoda and several other small phyla, form the superphylum Ecdysozoa. Numerous peptidomic studies have been undertaken for both the arthropods and nematodes, resulting in the identification of many peptides from each group. In contrast, little is known about the peptides used as paracrines/hormones by species from the other ecdysozoan taxa. Here, transcriptome mining and bioinformatic peptide prediction were used to identify peptides in members of the Onychophora, Priapulida and Tardigrada, the only non-arthropod, non-nematode members of the Ecdysozoa for which there are publicly accessible expressed sequence tags (ESTs). The extant ESTs for each phylum were queried using 106 arthropod/nematode peptide precursors. Transcripts encoding calcitonin-like diuretic hormone and pigment-dispersing hormone (PDH) were identified for the onychophoran Peripatopsis sedgwicki, with transcripts encoding C-type allatostatin (C-AST) and FMRFamide-like peptide identified for the priapulid Priapulus caudatus. For the Tardigrada, transcripts encoding members of the A-type allatostatin, C-AST, insect kinin, orcokinin, PDH and tachykinin-related peptide families were identified, all but one from Hypsibius dujardini (the exception being a Milnesium tardigradum orcokinin-encoding transcript). The proteins deduced from these ESTs resulted in the prediction of 48 novel peptides, six onychophoran, eight priapulid and 34 tardigrade, which are the first described from these phyla.

  6. An automated system for measuring parameters of nematode sinusoidal movement

    Directory of Open Access Journals (Sweden)

    Stirbl Robert C

    2005-02-01

    Full Text Available Abstract Background Nematode sinusoidal movement has been used as a phenotype in many studies of C. elegans development, behavior and physiology. A thorough understanding of the ways in which genes control these aspects of biology depends, in part, on the accuracy of phenotypic analysis. While worms that move poorly are relatively easy to describe, description of hyperactive movement and movement modulation presents more of a challenge. An enhanced capability to analyze all the complexities of nematode movement will thus help our understanding of how genes control behavior. Results We have developed a user-friendly system to analyze nematode movement in an automated and quantitative manner. In this system nematodes are automatically recognized and a computer-controlled microscope stage ensures that the nematode is kept within the camera field of view while video images from the camera are stored on videotape. In a second step, the images from the videotapes are processed to recognize the worm and to extract its changing position and posture over time. From this information, a variety of movement parameters are calculated. These parameters include the velocity of the worm's centroid, the velocity of the worm along its track, the extent and frequency of body bending, the amplitude and wavelength of the sinusoidal movement, and the propagation of the contraction wave along the body. The length of the worm is also determined and used to normalize the amplitude and wavelength measurements. To demonstrate the utility of this system, we report here a comparison of movement parameters for a small set of mutants affecting the Go/Gq mediated signaling network that controls acetylcholine release at the neuromuscular junction. The system allows comparison of distinct genotypes that affect movement similarly (activation of Gq-alpha versus loss of Go-alpha function, as well as of different mutant alleles at a single locus (null and dominant negative alleles

  7. Acetylcholinesterases from entomopathogenic nematode Heterorhabditid bacteriophora: Susceptibility to insecticides and immunological characteristics.

    Science.gov (United States)

    Mohamed, Magda A; M E Mahdy, El-Sayed; Ghazy, Abd-El-Hady M; Ibrahim, Nihal M; El-Mezayen, Hatem A; Ghanem, Manal M E

    2017-01-01

    Acetylcholinesterases (AChEs) from the infective juveniles (IJs) of entomopathogenic nematode (EPN) have been investigated with respect to their susceptibility to insecticides and immunological characteristics, aiming at nominating the most compatible insecticide(s) to be used in conjunction with the most insecticide-tolerant EPN strain before incorporation in integrated pest management (IPM) programs. The inhibition kinetics of two purified AChE isoenzymes, AChEAII and AChEBI isolated from Heterorhabditid bacteriophora EM2 strain, by different insecticides revealed that the insensitivity to inhibition by such insecticides could be arranged in a descending order as; methomyl>carbofuran>acetamiprid>oxamyl>malathion. Except for malathion, the insecticides competitively inhibited AChEs with Ki values ranging from 0.1 to 15mM and IC50 values from 1.25 to 23mM. The two AChE isoforms are several folds less sensitive to inhibition by methomyl and carbofuran compared to those previously reported for other insect species. AChEBI was used as an immunogen to raise anti-AChEBI antisera in rabbits. The prepared antisera cross-reacted with AChEs of five different heterorhabditid nematode strains implying the presence of common epitopes shared along all the examined strains. Such studies could aid in the rational selection of the compatible insecticide(s) and the prepared polyclonal anti-AChE antisera would be a valuable immunodiagnostic tool for evaluating the most insecticide-tolerant EPN strain(s) in IPM programs. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Evaluating environmental drivers of spatial variability in free-living nematode assemblages along the Portuguese margin

    Science.gov (United States)

    Lins, Lidia; Leliaert, Frederik; Riehl, Torben; Pinto Ramalho, Sofia; Alfaro Cordova, Eliana; Morgado Esteves, André; Vanreusel, Ann

    2017-02-01

    Understanding processes responsible for shaping biodiversity patterns on continental margins is an important requirement for comprehending anthropogenic impacts in these environments and further management of biodiversity. Continental margins perform crucial functions linked to key ecological processes which are mainly structured by surface primary productivity and particulate organic matter flux to the seafloor, but also by heterogeneity in seafloor characteristics. However, to what extent these processes control local and regional biodiversity remains unclear. In this study, two isobathic parallel transects located at the shelf break (300-400 m) and upper slope (1000 m) of the western Iberian margin were used to test how food input and sediment heterogeneity affect nematode diversity independently from the spatial factors geographical distance and water depth. We also examined the potential role of connectedness between both depth transects through molecular phylogenetic analyses. Regional generic diversity and turnover were investigated at three levels: within a station, between stations from the same depth transect, and between transects. High variability in food availability and high sediment heterogeneity at the shelf-break transect were directly linked to high diversity within stations and higher variation in community structure across stations compared to the upper slope transect. Contrastingly, environmental factors (food availability and sediment) did not vary significantly between stations located at the upper slope, and this lack of differences were also reflected in a low community turnover between these deeper stations. Finally, differences in nematode communities between both transects were more pronounced than differences within each of the isobathic transects, but these changes were paralleled by the previously mentioned environmental changes. These results suggest that changes in community structure are mainly dictated by environmental factors

  9. Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes

    Science.gov (United States)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the

  10. Control of Nematode Disease of Eggplant (Solanum aethiopicum L. Using Manure

    Directory of Open Access Journals (Sweden)

    Stephen Adekunle Abolusoro

    2014-01-01

    Full Text Available Pot experiment was conducted in the year 2010 and repeated in 2011 to examine the effects of organic manure (poultry, cow dung, domestic waste and inorganic manure (NPK 15:15:15 on the yield, soil and root population of Meloidogyne incognita that infected Ethiopian eggplant Solanum aethiopicum in a greenhouse at Kabba College of Agriculture, Ahmadu Bello University, Kabba, Nigeria. Each of the organic manure was applied as soil amendment at the rate of 5 t/ha and the inorganic fertilizer (NPK was applied at the rate of 200 kg/ha while there was an untreated control that acted as standard check. The experimental design was a completely randomized design comprising of five treatments including control and each of the treatments was replicated four times. The results of the experiment showed that all the organic manures considered and NPK fertilizer were effective in suppressing nematode negative effects on the plant as manifested in improved yield, reduced soil and root population as well as in reduced gall index of the organic and inorganic manure treated plants compared with the control. The mean fruit yield of the manure treated plant was 18+1, of NPK fertilizer treated ones was 17, while the average fruit number in untreated control was 6.5. The organic and inorganic manures treated plants had bigger fruit size compared with control and were significantly different from the control. The soil and root population as well as root gall index were reduced in all the manure treatments compared with the control and they were significantly different from the control. The results of this experiment confirmed that organic manure can be utilized to manage root-knot nematode (M. incognita in soil.

  11. Host genetic resistance to root-knot nematodes, Meloidogyne spp., in Solanaceae: from genes to the field.

    Science.gov (United States)

    Barbary, Arnaud; Djian-Caporalino, Caroline; Palloix, Alain; Castagnone-Sereno, Philippe

    2015-12-01

    Root-knot nematodes (RKNs) heavily damage most solanaceous crops worldwide. Fortunately, major resistance genes are available in a number of plant species, and their use provides a safe and economically relevant strategy for RKN control. From a structural point of view, these genes often harbour NBS-LRR motifs (i.e. a nucleotide binding site and a leucine rich repeat region near the carboxy terminus) and are organised in syntenic clusters in solanaceous genomes. Their introgression from wild to cultivated plants remains a challenge for breeders, although facilitated by marker-assisted selection. As shown with other pathosystems, the genetic background into which the resistance genes are introgressed is of prime importance to both the expression of the resistance and its durability, as exemplified by the recent discovery of quantitative trait loci conferring quantitative resistance to RKNs in pepper. The deployment of resistance genes at a large scale may result in the emergence and spread of virulent nematode populations able to overcome them, as already reported in tomato and pepper. Therefore, careful management of the resistance genes available in solanaceous crops is crucial to avoid significant reduction in the duration of RKN genetic control in the field. From that perspective, only rational management combining breeding and cultivation practices will allow the design and implementation of innovative, sustainable crop production systems that protect the resistance genes and maintain their durability.

  12. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte-Pradines, C., E-mail: catherine.lecomte-pradines@irsn.fr [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Bonzom, J.-M. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Della-Vedova, C. [Magelis, 6, rue Frederic Mistral, 84160 Cadenet (France); Beaugelin-Seiller, K. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LM2E, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France); Villenave, C. [ELISOL Environment, Building 12, Campus de la Gaillarde, 2 place Viala, 34060 Montpellier cedex 2 (France); Gaschak, S. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Coppin, F. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, L2BT, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Dubourg, N. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, GARM Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Maksimenko, A. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Adam-Guillermin, C. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Garnier-Laplace, J. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France)

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h{sup −1}. These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H′). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h{sup −1}. This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites

  13. NemaPath: online exploration of KEGG-based metabolic pathways for nematodes

    Directory of Open Access Journals (Sweden)

    Wang Zhengyuan

    2008-11-01

    Full Text Available Abstract Background Nematode.net http://www.nematode.net is a web-accessible resource for investigating gene sequences from parasitic and free-living nematode genomes. Beyond the well-characterized model nematode C. elegans, over 500,000 expressed sequence tags (ESTs and nearly 600,000 genome survey sequences (GSSs have been generated from 36 nematode species as part of the Parasitic Nematode Genomics Program undertaken by the Genome Center at Washington University School of Medicine. However, these sequencing data are not present in most publicly available protein databases, which only include sequences in Swiss-Prot. Swiss-Prot, in turn, relies on GenBank/Embl/DDJP for predicted proteins from complete genomes or full-length proteins. Description Here we present the NemaPath pathway server, a web-based pathway-level visualization tool for navigating putative metabolic pathways for over 30 nematode species, including 27 parasites. The NemaPath approach consists of two parts: 1 a backend tool to align and evaluate nematode genomic sequences (curated EST contigs against the annotated Kyoto Encyclopedia of Genes and Genomes (KEGG protein database; 2 a web viewing application that displays annotated KEGG pathway maps based on desired confidence levels of primary sequence similarity as defined by a user. NemaPath also provides cross-referenced access to nematode genome information provided by other tools available on Nematode.net, including: detailed NemaGene EST cluster information; putative translations; GBrowse EST cluster views; links from nematode data to external databases for corresponding synonymous C. elegans counterparts, subject matches in KEGG's gene database, and also KEGG Ontology (KO identification. Conclusion The NemaPath server hosts metabolic pathway mappings for 30 nematode species and is available on the World Wide Web at http://nematode.net/cgi-bin/keggview.cgi. The nematode source sequences used for the metabolic pathway

  14. The oxygen consumption rates of different life stages of the endoparasitic nematode

    Directory of Open Access Journals (Sweden)

    Willie van Aardt

    2010-01-01

    Full Text Available The oxygen consumption rates of different life stages of the endoparasitic nematode, Pratylenchus zeae (Nematoda: Tylenchida during non- and post-anhydrobiosisPratylenchus zeae, widely distributed in tropical and subtropical regions, is an endoparasite in roots of maize and other crop plants. The nematode is attracted to plant roots by CO2 and root exudates and feeds primarily on cells of the root cortex, making channels and openings where the eggs are deposited, with the result that secondary infection occurs due to bacteria and fungi. Nothing is known about the respiration physiology of this nematode and how it manages to survive during dry seasons. To measure the oxygen consumption rate (VO2 of individual P. zeae (less than half a millimeter long, a special measuring technique namely Cartesian diver micro-respirometry was applied. The Cartesian divers were machined from Perspex, and proved to be more accurate to measure VO2 compared with heavier glass divers used in similar experiments on free living nematodes. An accuracy of better than one nanoliter of oxygen consumed per hour was achieved with a single P. zeae inside the diver. Cartesian diver micro-respirometry measurements are based in principle on the manometric changes that occur in a fl otation tube in a manometer set-up when oxygen is consumed by P. zeae and CO2 from the animal is chemically absorbed. VO2 was measured for eggs (length: < 0.05 mm, larvae (length: 0.36 mm and adults (length: 0.47 mm before induction to anhydrobiosis. P. zeae from infected maize roots were extracted and exposed aseptically to in vitro maize root cultures in a grow cabinet at 50 % to 60% relative humidity at 28 ºC using eggs, larvae and adults. VO2 was also measured for post-anhydrobiotic eggs, larvae and adults by taking 50 individuals, eggs and larvae from the culture and placing them in Petri-dishes with 1% agar/water to dry out for 11 days at 28 ºC and 50% relative humidity. The VO2 was measured

  15. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone.

    Science.gov (United States)

    Lecomte-Pradines, C; Bonzom, J-M; Della-Vedova, C; Beaugelin-Seiller, K; Villenave, C; Gaschak, S; Coppin, F; Dubourg, N; Maksimenko, A; Adam-Guillermin, C; Garnier-Laplace, J

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h(-1). These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H'). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h(-1). This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites. This might

  16. Carbofuran effects in soil nematode communities: using trait and taxonomic based approaches.

    Science.gov (United States)

    Chelinho, Sónia; Dieter Sautter, Klaus; Cachada, Anabela; Abrantes, Isabel; Brown, George; Costa Duarte, Armando; Sousa, José Paulo

    2011-10-01

    This work intends to implement the use of native soil nematode communities in ecotoxicological tests using a model pesticide and two geographically nematode communities (Mediterranean and sub-tropical) in order to obtain new perspectives on the evaluation of the toxic potential of chemical substances. The environmental condition of the nematode communities was described using a trait-based approach (grouping the organisms according to their feeding traits) and a traditional taxonomic method (identification to family level). Effects on total nematode abundance, number of families and abundance of nematode feeding groups as well as potential shifts in both trophic and family structure were assessed. Agricultural soils from Curitiba (Brazil) and Coimbra (Portugal) were sampled and the corresponding nematode communities were extracted. Part of the collected soil was defaunated and spiked with four doses of a carbofuran commercial formulation. Afterwards each of the replicates was inoculated with a nematode suspension containing ≈200 or 300 nematodes. After 14 and 28 d of exposure the nematodes were extracted, counted and identified at family level and separately classified according to their feeding traits. The patterns of nematode responses revealed a decrease in the total abundance and a reduction in the number of families. Despite the similar effects observed for both communities, statistically significant toxic effects were only found within the Portuguese community. The total nematode abundance was significantly reduced at the highest carbofuran concentrations and significant shifts in the family structure were detected. However, the trophic structure, i.e., the contribution of each feeding group for the overall community structure, did not significantly change along the contamination gradient. Results showed that using such a trait-based approach may increase the ecological relevance of toxicity data, by establishing communalities in the response to a chemical

  17. Host and vector surveys for the pinewood nematode bursaphelenchus xylophilus (steiner and buhrer) nickle (nematoda: aphelenchoididae) in canada. Information report No. N-X-285

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, W.W.; Hudak, J.; Raske, A.G.; Magasi, L.P.

    1992-01-01

    The pinewood nematode is an important forest pest because it causes wilting and considerable tree mortality, particularly in Japan. It was first reported in Manitoba in 1982, although there are no cases of tree mortality in Canada. It is ranked in the first level as a potentially important pest internationally and the Scandinavian countries have restricted the importation of conifer chips and timber from countries where the pest is known to occur, a major concern of Canadian forest managers and lumber exporters. In 1985, the Forest Insect and Disease Survey began a nationwide survey to determine the distribution of the pinewood nematode. This report briefly reviews its history and biology and presents the results of the Canadian survey.

  18. Evaluation of the Effect of Ecologic on Root Knot Nematode, Meloidogyne incognita, and Tomato Plant, Lycopersicon esculenum

    Directory of Open Access Journals (Sweden)

    Gary W. Lawrence

    2008-06-01

    Full Text Available Nonchemical methods and strategies for nematode management including cultural methods and engineered measures have been recommended as an alternative to methyl bromide (a major soil fumigant, due to its role in the depletion of the ozone layer. Hence, an international agreement has recently been reached calling for its reduced consumption and complete phasing out. This present research evaluates the potential of Ecologic, a biological, marine shell meal chitin material, as a soil amendment management agent for root knot nematode, Meloidogyne incognita, control, and its effect on the growth of Floradel tomato plant, Lycopersicon esculentum. To accomplish this goal, studies were conducted during which, experimental pots were set up in greenhouse environments using sterilized soil inoculated with 5,000 root-knot eggs per 1500 g soil. There were 4 treatments and 5 replications. Treatments were: No chitin; 50 g chitin; 100 g chitin; and 200 g chitin. A two-week wait period following Ecologic amendment preceded Floradel tomato planting to allow breakdown of the chitin material into the soil. Fresh and dry weights of shoot and root materials were taken as growth end-points. A statistically significant difference (p ≤ 0.05 was obtained with regard to the growth rate of L. esculentum at 100 g chitin treatment compared to the control with no chitin. Mean fresh weights of Floradel tomato were 78.0 ± 22.3g, 81.0 ± 20.3g, 109.0 ± 25.4g and 102.0 ± 33.3g at 0, 50, 100 and 200g chitin, respectively. The analysis of root knot nematode concentrations indicated a substantial effect on reproduction rate associated with chitin amendment. Study results showed a significant decrease in both root knot nematode eggs and juveniles (J2 at 100g and 200g Ecologic chitin levels, however, an increase in nematode concentrations was recorded at the 50g Ecologic chitin level (p ≤ 0.05. The mean amounts of J2 population, as

  19. Control of the pinewood nematode Bursaphelenchus xylophilus by essential oils and extracts obtained from plants: a review.

    OpenAIRE

    Barbosa, Pedro; Vieira, Paulo; Dias, LS; Pedro, LG; Barroso, JG; Figueiredo, AC; Mota, Manuel

    2012-01-01

    The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a serious threat to forest ecosystems at a global scale. The nematode has become a major quarantine problem due to its capability to completely destroy Pinus spp. trees, with great damage to the wood industry. Controlling the nematode inside a living tree is quite difficult, the techniques used being often ineffective and quite expensive. In the coming years, most chemicals used to control nematodes will be banned and ...

  20. RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema

    Directory of Open Access Journals (Sweden)

    Shruti Yadav

    2017-06-01

    Full Text Available Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host–pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila or axenic (lacking X. nematophila nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance.

  1. RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema.

    Science.gov (United States)

    Yadav, Shruti; Daugherty, Sean; Shetty, Amol Carl; Eleftherianos, Ioannis

    2017-06-07

    Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host-pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq) to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila) or axenic (lacking X. nematophila) nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance. Copyright © 2017 Yadav et al.

  2. RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema

    Science.gov (United States)

    Yadav, Shruti; Daugherty, Sean; Shetty, Amol Carl; Eleftherianos, Ioannis

    2017-01-01

    Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host–pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq) to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila) or axenic (lacking X. nematophila) nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance. PMID:28450373

  3. In vivo efficacy of chicory silage against parasitic nematodes in cattle

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Desrues, Oliver; Williams, A.;

    Infections with parasitic nematodes are a persistent risk for grazing cattle, which is met with widespread use of synthetic anthelmintics. However, heavy reliance on these drugs may lead to selection of drug-resistant nematodes. Integrated control strategies, including anti-parasitic crops, are n...

  4. Nematodes as sentinels of heavy metals and organic toxicants in the soil

    NARCIS (Netherlands)

    Ekschmitt, K.; Korthals, G.W.

    2006-01-01

    Field and laboratory research has repeatedly shown that free-living soil nematodes differ in their sensitivity to soil pollution. In this paper, we analyze whether nematode genera proved sensitive or tolerant toward heavy metals and organic pollutants in six long-term field experiments. We discuss o

  5. RNA Interference: A Novel Source of Resistance to Combat Plant Parasitic Nematodes

    Directory of Open Access Journals (Sweden)

    Sagar Banerjee

    2017-05-01

    Full Text Available Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances like RNA interference (RNAi to engineer resistance against these devastating parasites. First demonstrated in the model free living nematode, Caenorhabtidis elegans; the phenomenon of RNAi has been successfully used to suppress essential genes of plant parasitic nematodes involved in parasitism, nematode development and mRNA metabolism. Synthetic neurotransmitants mixed with dsRNA solutions are used for in vitro RNAi in plant parasitic nematodes with significant success. However, host delivered in planta RNAi has proved to be a pioneering phenomenon to deliver dsRNAs to feeding nematodes and silence the target genes to achieve resistance. Highly enriched genomic databases are exploited to limit off target effects and ensure sequence specific silencing. Technological advances like gene stacking and use of nematode inducible and tissue specific promoters can further enhance the utility of RNAi based transgenics against plant parasitic nematodes.

  6. Heterodera schachtii nematodes interfere with aphid-plant relations on Brassica oleracea.

    Science.gov (United States)

    Hol, W H Gera; De Boer, Wietse; Termorshuizen, Aad J; Meyer, Katrin M; Schneider, Johannes H M; Van Der Putten, Wim H; Van Dam, Nicole M

    2013-09-01

    Aboveground and belowground herbivore species modify plant defense responses differently. Simultaneous attack can lead to non-additive effects on primary and secondary metabolite composition in roots and shoots. We previously found that aphid (Brevicoryne brassicae) population growth on Brassica oleracea was reduced on plants that were infested with nematodes (Heterodera schachtii) prior (4 weeks) to aphid infestation. Here, we examined how infection with root-feeding nematodes affected primary and secondary metabolites in the host plant and whether this could explain the increase in aphid doubling time from 3.8 to 6.7 days. We hypothesized that the effects of herbivores on plant metabolites would depend on the presence of the other herbivore and that nematode-induced changes in primary metabolites would correlate with reduced aphid performance. Total glucosinolate concentration in the leaves was not affected by nematode presence, but the composition of glucosinolates shifted, as gluconapin concentrations were reduced, while gluconapoleiferin concentrations increased in plants exposed to nematodes. Aphid presence increased 4-methoxyglucobrassicin concentrations in leaves, which correlated positively with the number of aphids per plant. Nematodes decreased amino acid and sugar concentrations in the phloem. Aphid population doubling time correlated negatively with amino acids and glucosinolate levels in leaves, whereas these correlations were non-significant when nematodes were present. In conclusion, the effects of an herbivore on plant metabolites were independent of the presence of another herbivore. Nematode presence reduced aphid population growth and disturbed feeding relations between plants and aphids.

  7. Controlling tulip stem nematodes in tulip bulbs by a hot water treatment

    NARCIS (Netherlands)

    Dam, van M.F.N.

    2013-01-01

    A hot water treatment (HWT) protocol is needed to control tulip stem nematode (TSN) in tulip bulbs. A HWT above approximately 45°C in tulips is assumed to be harmful to the bulbs. Experience with HWT to destroy stem nematodes in daffodils shows that the required temperature for this is 4 hours at

  8. First report of the root-knot nematode Meloidogyne ethiopica on tomato in Slovenia

    NARCIS (Netherlands)

    Sirca, S.; Urek, G.; Karssen, G.

    2004-01-01

    The root-knot nematode Meloidogyne ethiopica Whitehead originally described from Tanzania is also distributed in South Africa, Zimbabwe, and Ethiopia (3). Although this species is a relatively unknown root-knot nematode, M. ethiopica parasitizes several economical important crops, such as tomato, co

  9. First report of plant-parasitic nematode Meloidoderita salina in the Netherlands

    NARCIS (Netherlands)

    Ashrafi, S.; Helder, J.; Elsen, van den S.J.J.; Jansen, M.; Karssen, G.

    2014-01-01

    After the description of the root-parasitic nematode Meloidoderita salina from a tidal salt marsh in France (1), an additional sampling was carried out to search for the presence of this unusual nematode in a tidal salt marsh area close to Sint-Annaland, province Zeeland in the Netherlands. In Augus

  10. The Activation and Suppression of Plant Innate Immunity by Parasitic Nematodes

    NARCIS (Netherlands)

    Goverse, A.; Smant, G.

    2014-01-01

    Plant-parasitic nematodes engage in prolonged and intimate relationships with their host plants, often involving complex alterations in host cell morphology and function. It is puzzling how nematodes can achieve this, seemingly without activating the innate immune system of their hosts. Secretions r

  11. Canine Infections with Onchocerca lupi Nematodes, United States, 2011–2014

    Science.gov (United States)

    Giannelli, Alessio; Latrofa, Maria S.; Dantas-Torres, Filipe; Trumble, Nicole Scotty; Chavkin, Matt; Kennard, Gavin; Eberhard, Mark L.; Bowman, Dwight D.

    2015-01-01

    Infections with Onchocerca lupi nematodes are diagnosed sporadically in the United States. We report 8 cases of canine onchocercosis in Minnesota, New Mexico, Colorado, and Florida. Identification of 1 cytochrome c oxidase subunit 1 gene haplotype identical to 1 of 5 from Europe suggests recent introduction of this nematode into the United States. PMID:25897859

  12. RNA Interference: A Novel Source of Resistance to Combat Plant Parasitic Nematodes.

    Science.gov (United States)

    Banerjee, Sagar; Banerjee, Anamika; Gill, Sarvajeet S; Gupta, Om P; Dahuja, Anil; Jain, Pradeep K; Sirohi, Anil

    2017-01-01

    Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances like RNA interference (RNAi) to engineer resistance against these devastating parasites. First demonstrated in the model free living nematode, Caenorhabtidis elegans; the phenomenon of RNAi has been successfully used to suppress essential genes of plant parasitic nematodes involved in parasitism, nematode development and mRNA metabolism. Synthetic neurotransmitants mixed with dsRNA solutions are used for in vitro RNAi in plant parasitic nematodes with significant success. However, host delivered in planta RNAi has proved to be a pioneering phenomenon to deliver dsRNAs to feeding nematodes and silence the target genes to achieve resistance. Highly enriched genomic databases are exploited to limit off target effects and ensure sequence specific silencing. Technological advances like gene stacking and use of nematode inducible and tissue specific promoters can further enhance the utility of RNAi based transgenics against plant parasitic nematodes.

  13. Immunofluorescent Localization of Tobacco Ringspot Nepovirus in the Vector Nematode Xiphinema americanum.

    Science.gov (United States)

    Wang, S; Gererich, R C

    1998-09-01

    ABSTRACT An indirect immunofluorescent technique was developed to localize tobacco ringspot nepovirus (TRSV) in the vector nematode Xiphinema americanum sensu stricto. A population of this nematode that efficiently transmitted TRSV was given an acquisition access period of 10 days on TRSV-infected cucumber. Treatment of fragments of viruliferous nematodes with a polyclonal antiserum against TRSV followed by fluorescein isothiocyanate-conjugated goat anti-rabbit immunoglobulin G resulted in virus-specific bright fluorescence only in the lumen of the stylet extension and esophagus. Virus-specific fluorescent signals were observed in the virus-retention region of 44% of the nematode fragments examined. The percentage of nematodes labeled with virus-specific fluorescence increased as the acquisition access period increased from 0 to 22 days; the increase paralleled the increase in the transmission efficiency of the nematode population. Visualization of the entire virus-retention region of individual nematodes within a population of vector or nonvector nematodes provides a rapid and simple means of monitoring specific attachment of plant viruses.

  14. A novel approach to biocontrol: release of live insect hosts pre-infected with entomopathogenic nematodes

    Science.gov (United States)

    As a new application approach, we tested the efficacy of releasing live insect hosts that were pre-infected with entomopathogenic nematodes against insect pests living in cryptic habitats. We hypothesized that the pre-infected hosts could carry the next generation of emerging nematode infective juv...

  15. Preferred use of bacteria over phytoplankton by deep-sea nematodes in polar regions

    NARCIS (Netherlands)

    Ingels, J.; Driessche, Van den P.; Mesel, de I.G.; Vanhove, S.; Moens, T.; Vanreusel, A.

    2010-01-01

    The present study explored the selective feeding properties of Antarctic and Arctic deep-sea nematodes within an experimental setup. Nematodes are assumed to play an important role in the carbon flux within the polar bathyal food webs, but knowledge about their natural diets is limited. For the firs

  16. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    Science.gov (United States)

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

  17. Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) for Biological Control of Soil Pests

    OpenAIRE

    HAZIR, Selçuk; Kaya, Harry K.; Stock, S. Patricia; KESKİN, Nevin

    2014-01-01

    Several species of entomopathogenic nematodes in the families Steinernematidae (Steinernema) and Heterorhabditidae (Heterorhabditis) are being produced commercially and used as biological control agents against many soil insect pests and insects in cryptic habitats in many parts of the world. These nematodes, which are mutualistically associated with bacteria (Steinernema with Xenorhabdus bacteria and Heterorhabditis with Photorhabdus bacteria), offer a number of advantages because they have ...

  18. Multiple species-specific controls of root-feeding nematodes in natural soils

    NARCIS (Netherlands)

    Piśkiewicz, A.M.; Duyts, H.; Van der Putten, W.H.

    2008-01-01

    One of the major limitations to enhance sustainability of crop production systems is the inability to control root-feeding nematodes without using chemical biocides. In soils under wild vegetation, however, root-feeding nematodes affect plant performance and plant community composition varying from

  19. A review of introductions of pathogens and nematodes for classical biological control of insects and mites

    Science.gov (United States)

    Ann E. Hajek; Michael L. McManus; Italo Delalibera Junior

    2007-01-01

    Compared with parasitoids and predators, classical biological control programs targeting arthropod pests have used pathogens and nematodes very little. However, some pathogens and nematodes that have been introduced have become established and provided excellent control and have been introduced in increasing numbers of areas over decades, often after distributions of...

  20. Community composition, diversity and metabolic footprints of soil nematodes in differently-aged temperate forests

    NARCIS (Netherlands)

    Zhang, Xiaoke; Guan, Pingting; Wang, Yaolei; Li, Qi; Zhang, Shixiu; Zhang, Zhiyong; Bezemer, T. Martijn; Liang, Wenju

    2015-01-01

    Abstract Soil nematode communities can provide important information about soil food web structure and function. However, how soil nematode communities and their metabolic footprints change over time in temperate forests is not well known. We examined the changes in the composition, diversity and me

  1. On the relationships between nematodes, mycorrhizal fungi and plants: functional composition of species and plant performance

    NARCIS (Netherlands)

    Brussaard, L.; Kuyper, T.W.; Goede, de R.G.M.

    2001-01-01

    We analysed data from descriptive and experimental studies on the possible relationships between plants, nematodes and mycorrhizal fungi in (successional) plant communities in The Netherlands. A key role for pathogenic nematodes in cyclic succession in grazed grassland confirmed similar results in

  2. Optimization of a host diet for in vivo production of entomopathogenic nematodes

    Science.gov (United States)

    In previous studies, we developed an improved diet for Tenebrio molitor, a host that is used for in vivo nematode production, and we demonstrated that single insect diet components (e.g., lipids and proteins) can have a positive or negative impact on entomopathogenic nematode fitness and quality. I...

  3. Low cost production of nematodes for biological control of insect pests

    Science.gov (United States)

    Entomopathogenic nematodes are produced in two ways: in artificial media using liquid or solid fermentation methods (in vitro) or by mass producing insect hosts to be artificially exposed to mass infection by nematodes (in vivo). The yellow mealworm (Tenebrio molitor) is a good host for in vivo nema...

  4. Successes and failures in the use of parasitic nematodes for pest control

    NARCIS (Netherlands)

    Georgis, R.; Koppenhöfer, A.M.; Lacey, L.A.; Bélair, G.; Duncan, L.W.; Grewal, P.S.; Samish, M.; Tan, L.; Torr, P.; Tol, van R.W.H.M.

    2006-01-01

    Advances in mass-production and formulation technology of entomopathogenic nematodes, the discovery of numerous isolates/strains and the desirability of reducing pesticide usage have resulted in a surge of scientific and commercial interest in these nematodes. The lessons learned from earlier

  5. Molecular characterization of the beet cyst nematode (Heterodera schachtii) resistance locus Hs1.

    NARCIS (Netherlands)

    Salentijn, E.M.J.

    1995-01-01

    The white beet cyst nematode (BCN), Heterodera schachtii Schm. is a serious pest in sugar beet ( B. vulgaris L.) cultivation and is widely distributed throughout most of the beet-growing areas in the world (Cooke 1987). The economical losses due to infestation with the nematode are considerable (app

  6. High infectivity of an endoparasitic fungus strain, Esteya vermicola, against nematodes.

    Science.gov (United States)

    Wang, Chun Yan; Fang, Zhe Ming; Sun, Bai Shen; Gu, Li Juan; Zhang, Ke Qin; Sung, Chang-Keun

    2008-08-01

    Esteya vermicola, as the first recorded endoparasitic fungus of pinewood nematodes, exhibits great potential as a biological agent against nematodes. However, only two strains of this species have been described so far. In this study, we identified a novel endoparasitic fungal strain, CNU 120806, isolated from infected nematodes in forest soil samples during a survey of nematophagous fungi in Korea. This strain showed similar morphological characteristics and infection mode with the two previously described strains of E. vermicola. All strains are characterized by the ability to produce two types of conidiogenous cells and conidia, and to parasitize nematodes with lunate adhesive conidia. Moreover, the CNU 120806 strain showed 100% identity with E. vermicola CBS 115803 when their partial sequences of 28S rRNA gene were compared. Molecular phylogenetic analysis further identified CNU 120806 as a strain of E. vermicola, by clustering CNU 120806 and E. vermicola CBS 115803 into a single subclade. Culture medium influenced the proportion of dimorphic CNU 120806 conidia, and further changed the adhesive and mortality rates of nematodes. The CNU 120806 strain exhibits high infection activity against nematodes on nutrient-rich PDA medium. Almost all tested nematodes were killed within 8 approximately 10 days after inoculation. This study provides justification for further research of E. vermicola, and the application and formulation of this fungus as a bio-control agent against nematodes.

  7. Multiple species-specific controls of root-feeding nematodes in natural soils

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Putten, van der W.H.

    2008-01-01

    One of the major limitations to enhance sustainability of crop production systems is the inability to control root-feeding nematodes without using chemical biocides. In soils under wild vegetation, however, root-feeding nematodes affect plant performance and plant community composition varying from

  8. Biological control of Otiorhynchus sulcatus by insect parasitic nematodes, Heterorhabditis spp. at low temperatures.

    NARCIS (Netherlands)

    Westerman, P.R.

    1997-01-01

    The black vine weevil, Otiorhynchus sulcatus, is an important pest in ornamentals and nursery stock in The Netherlands. The larvae, which feed on the root system of the plant, can be controlled by insect parasitic nematodes, Heterorhabditis. However, the presently available isolates of the nematode

  9. Controlling tulip stem nematodes in tulip bulbs by a hot water treatment

    NARCIS (Netherlands)

    Dam, van M.F.N.

    2013-01-01

    A hot water treatment (HWT) protocol is needed to control tulip stem nematode (TSN) in tulip bulbs. A HWT above approximately 45°C in tulips is assumed to be harmful to the bulbs. Experience with HWT to destroy stem nematodes in daffodils shows that the required temperature for this is 4 hours at 47

  10. Post-Plant nematicides for the control of root lesion nematode in red raspberry

    Science.gov (United States)

    There are currently few registered post-plant nematicides available to control root lesion nematode (Pratylenchus penetrans, RLN) in red raspberry (Rubus ideaus). The rate of raspberry decline due to RLN depends upon the nematode population density but usually occurs over a 3- to 4-year period. To ...

  11. The discovery of fluazaindolizine: A new product for the control of plant parasitic nematodes.

    Science.gov (United States)

    Lahm, George P; Desaeger, Johan; Smith, Ben K; Pahutski, Thomas F; Rivera, Michel A; Meloro, Tony; Kucharczyk, Roman; Lett, Renee M; Daly, Anne; Smith, Brenton T; Cordova, Daniel; Thoden, Tim; Wiles, John A

    2017-04-01

    Fluazaindolizine is a new highly effective and selective product for the control of plant parasitic nematodes. Specificity for nematodes coupled with absence of activity against the target sites of commercial nematicides suggests that fluazaindolizine has a novel mode of action. The discovery, structure-activity development and biological properties for this new class of nematicides are presented.

  12. Impact of grapevine (Vitis vinifera) varieties on reproduction of the northern root-knot nematode (Meloidogyne hapla)

    Science.gov (United States)

    Plant-parasitic nematodes are microscopic soil worms that attack the roots of grape plants and cause yield loss. One of the most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards is Meloidogyne hapla, the northern root-knot nematode. The selection of plant...

  13. Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: Bioaccumulation in the face of sequestration by nematodes

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stacey A., E-mail: srobinsc@connect.carleton.ca [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Forbes, Mark R., E-mail: mforbes6@gmail.com [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Hebert, Craig E., E-mail: Craig.Hebert@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1A 0H3 (Canada)

    2010-10-15

    Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values ({delta}{sup 15}N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. {delta}{sup 13}C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.

  14. Effects of gastrointestinal nematode infection on the ruminant immune system.

    Science.gov (United States)

    Gasbarre, L C

    1997-11-01

    Gastrointestinal (GI) nematodes of ruminants evoke a wide variety of immune responses in their hosts. In terms of specific immune responses directed against parasite antigens, the resulting immune responses may vary from those that give strong protection from reinfection after a relatively light exposure (e.g. Oesophagostomum radiatum) to responses that are very weak and delayed in their onset (e.g. Ostertagia ostertagi). The nature of these protective immune responses has been covered in another section of the workshop and the purpose of this section will be to explore the nature of changes that occur in the immune system of infected animals and to discuss the effect of GI nematode infections upon the overall immunoresponsiveness of the host. The discussion will focus primarily on Ostertagia ostertagi because this parasite has received the most attention in published studies. The interaction of Ostertagia and the host immune system presents what appears to be an interesting contradiction. Protective immunity directed against the parasite is slow to arise and when compared to some of the other GI nematodes, is relatively weak. Although responses that reduce egg output in the feces or increase the number of larvae undergoing inhibition may occur after a relatively brief exposure (3-4 months), immune responses which reduce the number of parasites that can establish in the host are not evident until the animal's second year. Additionally, even older animals that have spent several seasons on infected pastures will have low numbers of Ostertagia in their abomasa, indicating that sterilizing immune responses against the parasite are uncommon. In spite of this apparent lack of specific protective immune responses, infections with Ostertagia induce profound changes in the host immune system. These changes include a tremendous expansion of both the number of lymphocytes in the local lymph nodes and the number of lymphoid cells in the mucosa of the abomasum. This expansion

  15. Soil and freshwater nematodes of the Iberian fauna: A synthesis

    Directory of Open Access Journals (Sweden)

    Peña-Santiago, R.

    2006-12-01

    Full Text Available The first available compilation of Iberian soil and freshwater nematodes is presented in this paper. The inventory is currently made up of 981 species belonging to 236 genera, 77 families and 12 orders. Data of the Iberian nematode fauna are compared with other components of the Iberian biota, as well as the nematode fauna of other geographical regions. Quantitative and qualitative aspects of the nematode inventory are analyzed and discussed, paying special attention to the kind of information available for each species, and concluding that practically one-third of Iberian species are deficiently characterized and need further study. Endemicity of Iberian species is also considered: 143 species, 14.6% of the total, are restricted (in their distribution to the Iberian geography, most of them being members of the orders Dorylaimida (87 and Tylenchida (29, which are also the most diversified nematode taxa. Practical or applied interest of knowledge of the Iberian nematode fauna is commented and supported with examples and recent contributions. Finally, an alphabetical list of the species, ordered by specific name, is provided.

    En esta contribución se presenta una recopilación de las especies ibéricas de nematodos de suelo y de agua dulce, la primera de este tipo realizada hasta el momento. El inventario actual lo componen 981 especies de 236 géneros, 77 familias y 12 órdenes. Los datos correspondiente a la fauna ibérica de nematodos se compara con la de otros táxones de la biota ibérica. Se analizan y se discuten distintos aspectos cuantitativos y cualitativos de la fauna nematológica, con especial énfasis en el tipo de información disponible sobre cada especie, y se concluye que casi una tercera parte de las especies ibéricas permanecen insuficientemente caracterizadas, razón por la cual requieren de estudios adicionales. La endemicidad de las especies es así mismo objeto de atención: 143 especies, un 14.6% del total est

  16. Long-term effects of plant diversity and composition on soil nematode communities in model grasslands.

    Science.gov (United States)

    Viketoft, Maria; Bengtsson, Janne; Sohlenius, Björn; Berg, Matty P; Petchey, Owen; Palmborg, Cecilia; Huss-Danell, Kerstin

    2009-01-01

    An important component of plant-soil feedbacks is how plant species identity anddiversity influence soil organism communities. We examine the effects of grassland plant species growing alone and together up to a richness of 12 species on nematode diversity and feeding group composition, eight years after the establishment of experimental grassland plots at the BIODEPTH site in northern Sweden. This is a substantially longer time than most other experimental studies of plant effects on soil fauna. We address the hypotheses that (la) higher species or functional diversity of plants increases nematode diversity, as well as influences nematode community composition. Alternatively, (1b) individual plant species traits are most important for nematode diversity and community composition. (2) Plant effects on soil organisms will decrease with increasing number of trophic links between plants and soil fauna. Plant species identity was often more important than plant diversity for nematode community composition, supporting hypothesis 1b. There was a weak positive relation between plant and nematode richness;which could be attributed to the presence of the legume Trifolium pratense, but also to some other plant species, suggesting a selection or sampling effect. Several plant species in different functional groups affected nematode community composition. For example, we found that legumes increased bacterial-feeding nematodes, most notably r-selected Rhabditida, while fungal-feeding nematodes were enhanced by forbs. Other bacterial feeders and obligate root feeders were positively related to grasses. Plant effects were usually stronger on plant-, bacterial- and fungal-feeding nematodes than on omnivores/predators, which supports hypothesis 2. Our study suggests that plant identity has stronger effects than plant diversity on nematode community composition, but when comparing our results with similar previous studies the effects of particular plant species appear to vary. We

  17. Localization of Transmissible and Nontransmissible Viruses in the Vector Nematode Xiphinema americanum.

    Science.gov (United States)

    Wang, Shouhua; Gergerich, Rose C; Wickizer, Sandra L; Kim, Kyung S

    2002-06-01

    ABSTRACT The inner lining of the food canal of nematodes that transmit plantinfecting viruses is regarded as the retention region of viruses. To characterize the location of transmissible and nontransmissible viruses in the vector nematode Xiphinema americanum, three nepoviruses, Tobacco ringspot virus (TRSV), Tomato ringspot virus(TomRSV), and Cherry leaf roll virus(CLRV), and one non-nematode-transmissible virus, Squash mosaic virus (SqMV), were evaluated for transmission efficiency and localization sites in the nematode. Transmission trials showed highest transmission efficiency for TomRSV (38% with 1 and 100% with 10 nematodes, respectively), intermediate efficiency for TRSV (27% with 1 and 65% with 10 nematodes, respectively), and no transmission for CLRV and SqMV. Electron microscopy and immunofluorescent labeling revealed that TRSV was primarily localized to the lining of the lumen of the stylet extension and the anterior esophagus, but only rarely in the triradiate lumen. Within a nematode population, particles of TRSV were no longer observed in these three regions 10 weeks after acquisition, and it is assumed that there was gradual and random loss of the virus from these areas. The percentage of nematodes that were labeled by virus-specific immunofluorescent labeling in a population of viruliferous nematodes decreased gradually after TRSV acquisition when the nematodes were placed on a nonhost of the virus, and the loss of immunofluorescent labeling paralleled the decrease in the ability of the nematode population to transmit the virus. TomRSV was localized only in the triradiate lumen based on thin-section electron microscopy. No virus-like particles were observed in any part of the food canal of nematodes that had fed on CLRV-infected plants. Virus-like particles that appeared to be partially degraded were observed only in the triradiate lumen of nematodes that had fed on SqMV-infected plants. These results clarified the status of localization of two

  18. Effect of free-air CO2 enrichment on nematode communities in a Chinese farmland ecosystem

    Institute of Scientific and Technical Information of China (English)

    LI Qi; LIANG Wen-ju; JIANG Yong; ZHU Jian-guo; KONG Chui-hua

    2005-01-01

    At a rice-wheat rotational free-air CO2 enrichment(FACE) platform, the effect of elevated atmospheric CO2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO2 (ambient 370 μl/L + 200 μl/L).32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effectof elevated atmospheric CO2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO2 may indicate the change of soil food web.

  19. 'David and Goliath' of the soil food web - Flagellates that kill nematodes

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Rønn, Regin

    2008-01-01

    Nematodes and flagellates are important bacterial predators in soil and sediments. Generally, these organisms are considered to be competitors for bacterial food. We studied the interaction among flagellates and nematodes using axenic liquid cultures amended with heat-killed bacteria as food...... and showed for the first time that a small and common soil flagellate (Cercomonas sp.) is able to attack and kill the much larger nematode Caenorhabditis elegans. The killing process is not caused by soluble metabolites but requires direct contact between the flagellate cells and the nematode surface...... and occurs rapidly (within a few hours) at high flagellate density. At lower flagellate density, adult nematodes sometimes avoid attachment of flagellates, feed on them and become the dominant bacterial predator. Considering that bacterial feeders affect bacterial communities differently, and that one...

  20. Influence of different fertilizer types of zucchini (Cucurbita pepo) on the structure of nematode communities.

    Science.gov (United States)

    Haytova, D; Bileva, T

    2011-01-01

    Increasing efficiency of production of vegetable crops is directly related to search for appropriate solution to increase their productivity. Organic amendments have been used for centuries to improve soil fertility and crop yield. Our study suggests that organic amendments can also be used as nematicidal agents. The survey was conducted on Experimental field of Department Horticulture at Agricultural University of Plovdiv, Bulgaria in 2009 on nematode infested sites. Combination with two types of fertilizers was used to investigate their effects on the community of soil nematodes. Characterization and comparative analysis among treatments of soil nematode community structure based on different ecological measures such as total nematode abundance, number of genera, trophic diversity and etc., was made. Changes in the composition and structure of nematode community as result of different fertilizer types were assessed.

  1. Orsay, Santeuil and Le Blanc viruses primarily infect intestinal cells in Caenorhabditis nematodes.

    Science.gov (United States)

    Franz, Carl J; Renshaw, Hilary; Frezal, Lise; Jiang, Yanfang; Félix, Marie-Anne; Wang, David

    2014-01-05

    The discoveries of Orsay, Santeuil and Le Blanc viruses, three viruses infecting either Caenorhabditis elegans or its relative Caenorhabditis briggsae, enable the study of virus-host interactions using natural pathogens of these two well-established model organisms. We characterized the tissue tropism of infection in Caenorhabditis nematodes by these viruses. Using immunofluorescence assays targeting proteins from each of the viruses, and in situ hybridization, we demonstrate viral proteins and RNAs localize to intestinal cells in larval stage Caenorhabditis nematodes. Viral proteins were detected in one to six of the 20 intestinal cells present in Caenorhabditis nematodes. In Orsay virus-infected C. elegans, viral proteins were detected as early as 6h post-infection. The RNA-dependent RNA polymerase and capsid proteins of Orsay virus exhibited different subcellular localization patterns. Collectively, these observations provide the first experimental insights into viral protein expression in any nematode host, and broaden our understanding of viral infection in Caenorhabditis nematodes.

  2. In vitro effect of condensed tannin extract from acacia (Acacia mearnsii) on gastrointestinal nematodes of sheep.

    Science.gov (United States)

    Minho, Alessandro P; Bueno, Ives Cláudio Da S; Gennari, Solange Maria; Jackson, Frank; Abdalla, Adibe Luiz

    2008-09-01

    The aim of this study was to determine the inhibitory effects of condensed tannin extract from acacia on the feeding of first-stage larvae (L1) of Haemonchus contortus, Trichostrongylus vitrinus and Teladorsagia circumcincta. The experiment was developed such that the inhibition of feeding for each of the nematode species could be evaluated. L1 recovered from fecal samples from a donor with monospecific infection was incubated in several dilutions of acacia extract (AE). The LD50 was determined for the three species of nematodes. Polyethylene glycol (PEG) was added to all dilutions of AE to inactivate the condensed tannins (CT) from acacia and to confirm their effects on L1. The impact of CT on larval feeding inhibition was detected for all the species of nematodes (H. contortus, T. colubriformis and T. circumcincta). There were differences between the aqueouswater control and CT treated groups (P nematodes studied could be used as an alternative means for controlling nematodes in sheep.

  3. Influence of industrial heavy metal pollution on soil free-living nematode population.

    Science.gov (United States)

    Pen-Mouratov, Stanislav; Shukurov, Nosir; Steinberger, Yosef

    2008-03-01

    The effect of distance from a heavy metal pollution source on the soil nematode community (trophic structure, sex structure, and taxa composition) was investigated along a 15-km transect originating at the Almalyk Industrial Complex, Uzbekistan (pollution source). The soil nematode community was exposed to heavy metal influence both directly and through soil properties changes. Pollution effect on the density and biomass of soil free-living nematodes was found to be highest at pollution source, with fungivores and plant parasites dominating at the upper and deeper soil layers next to the pollution source. These groups decreased along the transect, yielding domination to bacteria- and fungi-feeders. The sex ratio of nematode communities was found to be dependent on heavy metal pollution levels, with the juveniles being the most sensitive nematode group. The Maturity and modified Maturity Indices, reflecting the degree of disturbance of the soil ecosystem, were found to be the most sensitive indices.

  4. Serological Differentiation of Plant-parasitic Nematode Species with Polyclonal and Monoclonal Antibodies.

    Science.gov (United States)

    Schots, A; Gommers, F J; Bakker, J; Egberts, E

    1990-01-01

    Although several attempts have been made to differentiate nematode species with polyclonal antisera, these efforts thus far have met with limited success because of extensive crossreactivities of the sera. Since the hybridoma technique offers the opportunity to develop more specific serological reagents, some research groups have recently started to apply this technology to the problem of species identification in nematology. Monoclonal antibodies (MA) that differentiate the potato-cyst nematodes Globodera rostochiensis and G. pallida, as well as MA specific for Meloidogyne species, have been developed. The possibilities of developing serodiagnostic tools for identification of nematodes recovered from soil samples and the implications of such monitoring of nematode infestations in view of integrated control of plant-parasitic nematodes are discussed.

  5. Effects of vegetation coverage on the spatial distribution of soil nematode trophic groups

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The spatial variability of total soil nematodes and trophic groups in bare and fallow plots in Shenyang Experi-mental Station of Ecology, Chinese Academy of Sciences was examined using geostatistics combined with classic statistics. Results showed that the soil pH value had a negative effect on plant-parasites in both bare and fallow plots; the mean number of total nematodes was significantly higher in fallow plots than in bare plots, which was 1485.3 and 464.0 individuals per 100 g dry soil in fallow and bare plots, respectively; the nugget (C0)/sill (C0+C) ratio of total nematodes, plant-parasites and bacterivores were lower in fallow plots (27.3%-45.6%) than in bare plots (49.5%-100%); the spatial distribution of total nematodes and trophic groups was found to be different between fallow and bare plots, which indicated that vegetation coverage had an effect on soil nematodes.

  6. Granular Nematicides as Adjuncts to Fumigants for Control of Cotton Root-knot Nematodes.

    Science.gov (United States)

    Jorgenson, E C

    1979-04-01

    Growth and yield of cotton were best with combinations of fumigants and organophosphate and carbamate nematicides. Organophosphates or carbamates used alone did not give season-long control of root-knot nematodes. Long-term control was poor because the temporary sublethal effects of these materials diminished soon enough lhat the nematodes could reproduce. The nematodes survived the treatments and a year of nonhost culture, and damaged a susceptible host crop 2 years after treatment. No such damage occurred in plots treated with fumigant, fumigant plus organophosphate, or fumigant plus carbamate. Treatment of seed and treatment of cotton, either in furrow at planting or sidedressing at midseason, with organophosphate and carbamate nematicides resulted in little or no yield increase, because nematode control was only minimal and temporary; or in a yield decrease, because the toxicity of the materials was manifested when nematode populations were low.

  7. Distribution of plant-parasitic nematodes on sugarcane in louisiana and efficacy of nematicides.

    Science.gov (United States)

    Bond, J P; McGawley, E C; Hoy, J W

    2000-12-01

    A survey conducted from May 1995 through August 1998 revealed diverse nematode communities in Louisiana sugarcane fields. High populations of Mesocriconema, Paratrichodorus, Pratylenchus, and Tylenchorhynchus were widespread in nine sugarcane production parishes. Comparisons of plant cane and ratoon sugarcane crops indicated that nematode community levels increase significantly in successive ratoon crops. Nematicide trials evaluated the efficacy of aldicarb, ethoprop, and phorate against indigenous nematode populations. Aldicarb consistently increased the number of millable stalks, cane tonnage, and yield of sucrose in soils with a high sand content. Yield increases were concomitant with reductions in the density of the nematode community shortly after planting and at harvest. In soils with a higher clay content, the chemicals were less effective in controlling nematode populations and, as a result, yield increases were minimal.

  8. Treatment of Nematodes with Ozone Gas: A Sustainable Alternative to Nematicides

    Science.gov (United States)

    Msayleb, Nahed; Ibrahim, Saiid

    This study tests Ozone as a Nematicides' alternative. Nematode-infected soil samples were treated with ascending doses of O3 by submerging the outlet of an "MB1000 Ozone Generator" in the 40 ml samples; then to test the O3 nematicidal effect by gas fumigation, Ozone gas was released into a sealed bag containing 80 g of each of the 6 nematode-infected soil samples with ascending doses and a repetition of each. With water-ozonation, 900 mg O3 were needed to kill 100% of nematodes, and the O3-Nematodes LD50 was identified by 420 mg. With the second experiment, O3 soil fumigation for 50 minutes at a dose of 1,125 mg in an air volume of 5 litres, were needed to control 95% of living nematodes.

  9. Transcriptomic analysis of the entomopathogenic nematode Heterorhabditis bacteriophora TTO1

    Directory of Open Access Journals (Sweden)

    Spieth John

    2009-04-01

    Full Text Available Abstract Background The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results A total of 31,485 high quality ESTs were generated from cDNA libraries of the adult H. bacteriophora TTO1 strain. Cluster analysis revealed the presence of 3,051 contigs and 7,835 singletons, representing 10,886 distinct EST sequences. About 72% of the distinct EST sequences had significant matches (E value H. bacteriophora, among which are those encoding F-box-like/WD-repeat protein theromacin, Bax inhibitor-1-like protein, and PAZ domain containing protein. Gene Ontology terms were assigned to 6,685 of the 10,886 ESTs. A total of 168 microsatellite loci were identified with primers designable for 141 loci. Conclusion A total of 10,886 distinct EST sequences were identified from adult H. bacteriophora cDNA libraries. BLAST searches revealed ESTs potentially involved in parasitism, RNA interference, defense responses, stress responses, and dauer-related processes. The putative microsatellite markers identified in H. bacteriophora ESTs will enable genetic mapping and population genetic studies. These genomic resources provide the material base necessary for genome annotation, microarray development, and in-depth gene functional analysis.

  10. Lung and hearth nematodes in some Spanish mammals.

    Science.gov (United States)

    Alvarez, F; Iglesias, R; Bos, J; Rey, J; Sanmartin Durán, M L

    1991-01-01

    Thirteen host species belonging to the orders Rodentia, Insectivora and Carnivora from various localities in Galicia (NW Spain) were examined for heart and lung parasites. The following species were found: Parastrongylus dujardini (5.5%) in Apodemus sylvaticus, Crenosoma striatum in Erinaceus europaeus (83%), Angiostrongylus vasorum, Crenosoma vulpis and Eucoleus aerophilus in Vulpes vulpes (3, 3.46 and 0.50%, respectively), Crenosoma taiga in Putorius putorius (100%) and Crenosoma sp. in Meles meles (25%). In Crocidura russula nematode larvae were found (3.3%). Mus musculus, Rattus norvegicus, Rattus rattus, Talpa caeca, Sorex araneus, Genetta genetta and Canis lupus were not parasitized by lung or heart parasites.

  11. Nematode community structure in the vicinity of a metallurgical factory.

    Science.gov (United States)

    Salamún, Peter; Renčo, Marek; Miklisová, Dana; Hanzelová, Vladimíra

    2011-12-01

    Soil nematode communities (taxa composition, trophic structure, ecological indices) in the area of metallurgical factory (Oravské ferozliatinárske závody) in Široká, Northern Slovakia were investigated in 2009. The factory belongs to main sources of emissions originated by ferroalloy production in this region. Four sites (meadows) were selected in a downwind direction from the factory: site A was located 0.85 km far from the factory, and the other sites were maintained in approximately 2-km intervals from each other. Chemical analysis of soil samples showed low concentrations of heavy metals (As, Cd, Cr, Cu, Ni, Pb and Zn), with all values being under Slovak limit concentrations of heavy metals in soils. Only the Cd content in the soil sample from site A slightly exceeded the allowable threshold, but it was decreasing with the distance from the factory, similarly as remaining metals except Cr, with slightly increasing trend of concentration. Within 64 identified nematode genera, the Helicotylenchus, Paratylenchus, Pratylenchus, Acrobeloides, Cephalobus and Rhabditis were most common and eudominant. This was clearly reflected on the trophic structure of nematode communities, where plant feeding nematodes and bacteriovorous prevailed. Significant negative correlation (P < 0.05) was observed between the abundance of bacteriovores and the concentration of Cu in the soil. On the other hand, fungivores showed significant correlation with Ni and Cr (P < 0.05) as well as predators with Cd, Pb and Zn contents in the soil (P < 0.01). The highly significant correlation (P < 0.05; P < 0.01) was found between As, Cd, Ni, Pb and Zn and Maturity Index 2-5. A negative relationship was detected between Maturity Index and the concentration of Cr in the soil (P < 0.01). On the other hand, Cu was in positive correlation with MI values. The MI, reflecting the degree of disturbances and changes in the structure and function of the soil ecosystem, was found

  12. Evaluation the effect of albendazole against nematodes in sheep

    Directory of Open Access Journals (Sweden)

    M. I. Al-Farwachi

    2008-01-01

    Full Text Available Six sheep farms in Mosul city, Iraq randomly selected, were surveyed for gastrointestinal nematodes resistant to Albendazole. On each of 6 sheep farms, 20 lambs were randomly distributed into two equal groups untreated control group, and albendazole (benzimidazole group (10 mg/kg BW. Faecal egg counts and larval cultures were done at 7, 14, and 21 days after anthelmintic treatment. Resistance was apparent for albendazole on 4 farms out of 6 (66.7%. Post-treatment larval cultures indicated: Strongyloides papillosus, Marshalligia marshalli, Nematodirus spathiger and Haemonchus contortus.

  13. Anthelmintic resistance in cattle nematodes in the US.

    Science.gov (United States)

    Gasbarre, Louis C

    2014-07-30

    The first documented case of macrocyclic lactone resistance in gastrointestinal (GI) nematodes of cattle was seen in the US approximately 10 years ago. Since that time the increase incidence of anthelmintic resistance has continued at an alarming rate. Currently parasites of the genera Cooperia and/or Haemonchus resistant to generic or brand-name macrocyclic lactones have be demonstrated in more than half of all operations examined. Both of these parasite genera are capable of causing economic losses by decreasing food intake and subsequently animal productivity. Currently, there are no easy and quick means to detect anthelmintic resistant GI nematodes. Definitive identification requires killing of cattle. The most commonly used field detection method is the fecal egg count reduction test (FECRT). This method can be adapted for use as a screening agent for Veterinarians and producers to identify less than desired clearance of the parasites after anthelmintic treatment. Further studies can then define the reasons for persistence of the egg counts. The appearance of anthelmintic resistance is largely due to the development of very effective nematode control programs that have significantly improved the productivity of the US cattle industry, but at the same time has placed a high level of selective pressure on the parasite genome. The challenges ahead include the development of programs that control the anthelmintic resistant nematodes but at the same time result in more sustainable parasite control. The goal is to maintain high levels of productivity but to exert less selective pressures on the parasites. One of the most effective means to slow the development of drug resistance is through the simultaneous use of multiple classes of anthelmintics, each of which has a different mode of action. Reduction of the selective pressure on the parasites can be attained through a more targeted approach to drug treatments where the producer's needs are met by selective

  14. Cadmium toxicity in the free-living nematode, Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Popham, J.D.; Webster, J.M.

    1979-10-01

    The effect of cadmium on the fecundity, growth, and fine structure of the free-living nematode Caenorhabditis elegans was studied. High concentrations of cadmium significantly decreased the fecundity and growth of these organisms. Electron microscopy showed that cadmium modifies the structure of the mitochondria in the esophagus and intestine, causes the formation of inclusion bodies in the nucleus of esophageal cells, and alters the morphology of cytosomes in the intestinal cells. The results suggest that the decreased fecundity and growth of cadmium-exposed C. elegans may be due to cadmium interfering with nutrient uptake or assimilation or both.

  15. Motility of small nematodes in wet granular media

    CERN Document Server

    Juarez, G; Sznitman, J; Arratia, P E

    2010-01-01

    The motility behavior of the \\textit{Caenorhabditis elegans} is investigated in wet granular medium as a function of area density ($\\phi$) and dispersity. Surprisingly, the locomotion speed increases in granular media compared to free swimming. The surrounding structure of the medium leads to enhanced undulatory propulsion due to its ability to sustain a finite shear stress and convert lateral force into forward motion. For $\\phi > 0.55$, the nematode is observed to change its gate from swimming to crawling in polydisperse media \\textit{only}. This highlights the subtle difference in local structure between media.

  16. Tangling of Tethered Swimmers: Interactions between Two Nematodes

    Science.gov (United States)

    Backholm, Matilda; Schulman, Rafael D.; Ryu, William S.; Dalnoki-Veress, Kari

    2014-09-01

    The tangling of two tethered microswimming worms serving as the ends of "active strings" is investigated experimentally and modeled analytically. C. elegans nematodes of similar size are caught by their tails using micropipettes and left to swim and interact at different separations over long times. The worms are found to tangle in a reproducible and statistically predictable manner, which is modeled based on the relative motion of the worm heads. Our results provide insight into the intricate tangling interactions present in active biological systems.

  17. Influence of plant-parasitic nematodes on longleaf pine seedlings.

    Science.gov (United States)

    Ruehle, J L

    1973-01-01

    Seedlings of longleaf pine (Pinus palustris) were grown in 20-cm pots for 5 to 7 months in the greenhouse following inoculation with a high or low level of one of seven species of plant-parasitic nematodes. Belonolaimus longicaudatus and Helicotylenchus dihystera had no effect on seedling growth. High inoculum densities of Hoplolaimus galeatus and Tylenchorhynchus claytoni caused a significant reduction of fresh weight of seedling roots. Root and top weights of seedlings grown in soil infested with Meloidodera floridensis or Pratylenchus brachyurus were significantly less than those of seedlings in noninfested soil. Root growth of seedlings was stimulated by the higher inoculum density of Scutellonema brachyurum.

  18. Four acetylcholinesterase genes in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Arpagaus, M; Combes, D; Culetto, E; Grauso, M; Fedon, Y; Romani, R; Toutant, J P

    1998-01-01

    Whereas a single gene encodes acetylcholinesterase (AChE) in vertebrates and most insect species, four distinct genes have been cloned and characterized in the nematode Caenorhabditis elegans. We found that ace-1 (mapped to chromosome X) is prominently expressed in muscle cells whereas ace-2 (located on chromosome I) is mainly expressed in neurons. Ace-x and ace-y genes are located in close proximity on chromosome II where they are separated by only a few hundred base pairs. The role of these two genes is still unknown.

  19. A pathogenic nematode targets recognition proteins to avoid insect defenses.

    Directory of Open Access Journals (Sweden)

    Duarte Toubarro

    Full Text Available Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4, which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targets recognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions.

  20. A pathogenic nematode targets recognition proteins to avoid insect defenses.

    Science.gov (United States)

    Toubarro, Duarte; Avila, Mónica Martinez; Montiel, Rafael; Simões, Nelson

    2013-01-01

    Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targets recognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions.

  1. PLANT-PARASITIC NEMATODES ON STONE FRUITS AND CITRUS IN LEBANON

    Directory of Open Access Journals (Sweden)

    Said K. Ibrahim

    2016-06-01

    Full Text Available Ibrahim Said K., Ibrahim Azar, Christian Naser, Badran Akikki and Ludmilla Ibrahim. 2016. Plant-parasitic nematodes on stone fruits and citrus in Lebanon. Lebanese Science Journal, 17(1: 9-24. This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species. A total of 308 soil samples were collected from five different crops. Almost all surveyed areas showed infection with nematodes. The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%. Eighteen out of 308 soil samples were free of nematodes (5.8%. All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%, followed by citrus (97.6%, apple (88.7%, pear and quince (85.7%, and cherry (81.4%. The lowest infection (66.6% was detected on almond and apricot. The level of infestation varied from one area to another and ranged between 0.1 and 28 nematodes per 1 g of soil, with the highest number obtained on cherry. Several genera were identified based on morphological characters including: root-knot nematodes (Meloidogyne spp., Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus. Tylenchulus and Radopholus spp. were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp. were detected almost in all the samples collected from all the crops. Six chopped aromatic plants were tested in pot experiments to control nematodes population densities. The results revealed that carbofuran (nematicide was the most effective (88.48% in comparison to the plant materials. Allium sativum gave the highest control (76.52% followed by Tageta patula (72.0%, Cucurbita maxima (71.84% and Inula viscosa (63.96%. Origanum syriacum (55.04% and Thymus (53.72% were less effective in comparison to the rest of tested plant materials.

  2. About the translation of Chinese name for"cyst nematode"%"Cyst nematode"中文译名应该为"孢囊线虫"

    Institute of Scientific and Technical Information of China (English)

    李红梅; 陈书龙; 郑经武; 肖炎农; 彭德良

    2011-01-01

    The cyst nematode diseases become the main thread to safe production of Chinese agriculture in recent years. The difference in Chinese translation about cyst nematode was appeared in some of scientific books and literatures. Therefore, the critical literature searching and discusses was carried out in order to support the accurate Chinese translation of cyst nematodes.%农作物孢囊线虫病害(crop cyst nematode diseases)近年来已经成为威胁我国农业生产安全的重要植物病原线虫病害,鉴于国内部分有关学术论著与文献中,对"cyst nematode"的中译名写法有歧义,作者通过文献的阐述与论证,认为"cyst nematode"的中译名称应该为"孢囊线虫",而不用"胞囊线虫",以免引起混乱.

  3. The identification of cattle nematode parasites resistant to multiple classes of anthelmintics in a commercial cattle population in the US.

    Science.gov (United States)

    Gasbarre, Louis C; Smith, Larry L; Lichtenfels, J Ralph; Pilitt, Patricia A

    2009-12-23

    Resistance to modern anthelmintics by ruminant nematode parasites is an increasing problem throughout the world. To date the problem has largely been reported in parasites of small ruminants, but there are increasing reports of such resistance in nematodes recovered from cattle. Until now there have been no published reports of drug resistant parasites from cattle in North America. In 2002 a producer in the upper Midwest who backgrounds young cattle acquired from the southeastern US experienced lower than expected weight gain as well as apparent parasitic gastroenteritis in his cattle during the fall. Fecal sample results supported the suspicion that decreased productivity and diarrhea were the result of GI nematode parasitism. The operation used intensive grazing management and practiced strategically timed deworming for >17 year. In 2003, all animals were dewormed the first week of May with Ivomec Plus, then with Dectomax Injectable on 4 June and 17 July. On 31 July, 10 randomly taken fecal samples showed EPG values from 0 to 55. To assess whether the apparent decreased drug efficacy was the result of drug resistance in the nematode population, on 18 August approximately 150 heads, previously strategic timed dewormed, of 9-11 month old cattle from one pasture were selected for study. The calves were randomly assigned to 1 of 6 treatment groups: untreated (U), ivermectin injectable (I), moxidectin pour-on (M), doramectin injectable (D), eprinomectin pour-on (E), albendazole oral (A). Cattle were weighed prior to treatment and the drug was dosed according to label directions. Seven days later, 3 calves from each group were slaughtered for worm recovery. Fecal samples taken from the remaining animals at 14 days after treatment showed that the reduction of mean fecal EPG value for each group was: U-46%, I-52%, M-72%, D-61%, E-8%, and A-68%. Worm recovery from the slaughter calves showed that all groups harbored significant numbers of Haemonchus placei and H

  4. Lethal fighting in nematodes is dependent on developmental pathway: male-male fighting in the entomopathogenic nematode Steinernema longicaudum.

    Directory of Open Access Journals (Sweden)

    Annemie N R L Zenner

    Full Text Available Aggressive encounters occur between competitors (particularly males throughout the animal kingdom, and in some species can result in severe injury and death. Here we describe for the first time lethal interactions between male nematodes and provide evidence that the expression of this behaviour is developmentally controlled. Males of the entomopathogenic nematode Steinernema longicaudum coil around each other, resulting in injuries, paralysis and frequently death. The probability of death occurring between pairs of males was affected by the developmental pathway followed, being much greater among males that had passed through the infective juvenile (IJ, or dauer stage than among males that had not. Post-IJ males are found only in newly colonised hosts, typically with few competing males present. Killing those few competitors may secure valuable resources (both females and a host cadaver for nourishment of offspring. Non-IJ males develop in subsequent generations within a host cadaver, where the presence of many closely related male competitors increases the risk:benefit ratio of fighting. Thus, passage through the IJ stage primes males for enhanced aggression in circumstances where this is more likely to result in increased reproductive success. Fighting occurred between males developing in mixed-sex social groups, indicating that it is an evolved trait and not an abnormal response to absence of females. This is supported by finding high mortality of males, but not of females, across a range of population densities in insect cadavers. We propose that these nematodes, with their relatively simple organization, may be a useful model for studies of aggression.

  5. Anthelmintic Resistance of Strongyle Nematodes to Ivermectin and Fenbendazole on Cart Horses in Gondar, Northwest Ethiopia.

    Science.gov (United States)

    Seyoum, Zewdu; Zewdu, Alemu; Dagnachew, Shimelis; Bogale, Basazinew

    2017-01-01

    A study was conducted from November 2015 to April 2016 to determine fenbendazole and ivermectin resistance status of intestinal nematodes of cart horses in Gondar, Northwest Ethiopia. Forty-five strongyle infected animals were used for this study. The animals were randomly allocated into three groups (15 horses per group). Group I was treated with fenbendazole and Group II with ivermectin and Group III was left untreated. Faecal samples were collected from each cart horse before and after treatment. Accordingly, the reduction in the mean fecal egg count at fourteen days of treatment for ivermectin and fenbendazole was 97.25% and 79.4%, respectively. It was significantly different in net egg count between treatment and control groups after treatment. From the study, resistance level was determined for fenbendazole and suspected for ivermectin. In addition, a questionnaire survey was also conducted on 90 selected cart owners to assess their perception on anthelmintics. In the survey, the most available drugs in the study area used by the owners were fenbendazole and ivermectin. Most respondents have no knowledge about drug management techniques. Hence, animal health extension services to create awareness regarding anthelmintic management that plays a key role in reducing the anthelmintic resistance parasites.

  6. Anthelmintic Resistance of Strongyle Nematodes to Ivermectin and Fenbendazole on Cart Horses in Gondar, Northwest Ethiopia

    Directory of Open Access Journals (Sweden)

    Zewdu Seyoum

    2017-01-01

    Full Text Available A study was conducted from November 2015 to April 2016 to determine fenbendazole and ivermectin resistance status of intestinal nematodes of cart horses in Gondar, Northwest Ethiopia. Forty-five strongyle infected animals were used for this study. The animals were randomly allocated into three groups (15 horses per group. Group I was treated with fenbendazole and Group II with ivermectin and Group III was left untreated. Faecal samples were collected from each cart horse before and after treatment. Accordingly, the reduction in the mean fecal egg count at fourteen days of treatment for ivermectin and fenbendazole was 97.25% and 79.4%, respectively. It was significantly different in net egg count between treatment and control groups after treatment. From the study, resistance level was determined for fenbendazole and suspected for ivermectin. In addition, a questionnaire survey was also conducted on 90 selected cart owners to assess their perception on anthelmintics. In the survey, the most available drugs in the study area used by the owners were fenbendazole and ivermectin. Most respondents have no knowledge about drug management techniques. Hence, animal health extension services to create awareness regarding anthelmintic management that plays a key role in reducing the anthelmintic resistance parasites.

  7. Soil nematode assemblages indicate the potential for biological regulation of pest species

    Science.gov (United States)

    Steel, Hanne; Ferris, Howard

    2016-05-01

    In concept, regulation or suppression of target nematode pest species should be enhanced when an abundance of predator species is supported by ample availability of bacterial- fungal- and non-damaging plant-feeding prey species. We selected soils from natural and managed environments that represented different levels of resource availability and disturbance. In microcosm chambers of each soil, in its natural state or after heat defaunation, we introduced test prey species not already resident in the soils (Meloidogyne incognita and Steinernema feltiae). Survival of the test prey was determined after a 5-day bioassay exposure. Across the soils tested, predator abundance and biomass were greater in undisturbed soils with plentiful resources and lower in soils from agricultural sites. Suppressiveness to the two introduced species increased with both numerical abundance and metabolic footprint of the predator assemblages. The magnitude of the increase in suppressiveness was greater at low numbers of predators then dampened to an asymptotic level at greater predator abundance, possibly determined by temporal and spatial aspects of the bioassay system and/or satiation of the predators. The more resource-limited the predators were and the higher the metabolic predator footprint, the greater the suppressiveness. The applied implications of this study are that soil suppressiveness to pest species may be enhanced by increasing resources to predators, removing chemical and physical constraints to their survival and increase, and altering management practices so that predators and target prey are co-located in time and space.

  8. Sequence composition and mapping of BACs of cotton homoeologous chromosomes 11 and 21

    Science.gov (United States)

    Interest in cotton chromosome 11 and its homoeologous chromosome 21 derives from the discovery of resistance (R) or pathogen-induced R genes underlying QTLs involved in root-knot nematode, reniform nematode, Fusarium wilt, Verticillium wilt, and black root rot resistance. Genetic and QTL mapping eff...

  9. Population dynamics of host-specific root-feeding cyst nematode and resource quantity in the root zone of a clonal grass

    NARCIS (Netherlands)

    Stoel, C.D.; Duyts, H.; Putten, van der W.H.

    2006-01-01

    Recent studies have suggested that root-feeding nematodes influence plant community dynamics, but few studies have investigated the population dynamics of the nematodes. In coastal foredunes, feeding-specialist cyst nematodes (Heterodera spp.) are dominant in the soil nematode community and

  10. Population dynamics of a host-specific root-feeding cyst nematode and resource quantity in the root zone of a clonal grass

    NARCIS (Netherlands)

    Van der Stoel, C.D.; Duyts, H.; Van der Putten, W.H.

    2006-01-01

    Recent studies have suggested that root-feeding nematodes influence plant community dynamics, but few studies have investigated the population dynamics of the nematodes. In coastal foredunes, feeding-specialist cyst nematodes (Heterodera spp.) are dominant in the soil nematode community and

  11. Nematodes in the mallard (Anas platyrhynchos Linnaeus, 1758) and the common goldeneye (Bucephala clangula Linnaeus, 1758) (Anatidae) from Northern Europe.

    Science.gov (United States)

    Lebedeva, Daria I; Yakovleva, Galina A; Ieshko, Evgeny P

    2015-10-01

    There are first data on nematodes of Anas platyrhynchos Linnaeus, 1758 (mallard) and Bucephala clangula Linnaeus, 1758 (common goldeneye) from Northern Europe (Ladoga Lake region). The ducks were found to be infected with nine nematode species. A. platyrhynchos hosted eight nematode species and B. clangula was host to four nematode species. All species except Capillaria anatis were found in the region for the first time. Nematodes Amidostomum acutum, Streptocara crassicauda, and Tetrameres fissispina parasitized on both hosts and were the most abundant. The biggest number of parasites revealed was biohelminths with a direct life cycle.

  12. Use of the entomopathogenic nematode Heterorhabditis atacamensis CIA- NE07 in the control of banana weevil Cosmopolites sordidus in vitro

    Directory of Open Access Journals (Sweden)

    Marianela Amador

    2015-11-01

    Full Text Available Among the species of banana borers, black weevil (Cosmopolites sordidus is the most economically important pest in Costa Rica and worldwide. The control of C. sordidus in intensive production systems is mainly based on application of insecticides; therefore the search for biological alternatives, such as the use of entomopathogenic nematodes (EPN, is needed. The susceptibility of Cosmopolites sordidus to Heterorhabditis atacamensis CIANE07 was evaluated. The effect of inoculating H. atacamensis on larvae and adults of C. sordidus, in vitro and in artificially infected corms, was evaluated. Larvae inoculated with EPN had a mortality of 88% on the second day and 100% on the third day; no mortality was observed in adults. The treatments of 100, 500 and 1000 IJ.larvae-1 showed statistically significant differences from the control and theLD50 was 52 IJ.larvae-1. When the larvae were placed within the corms the LD50 increased to 375 IJ.larvae-1. The results indicate that the strain H. atacamensis CIA-NE07 is capable of locating and infecting weevil larvae within the banana corm and reach infection levels over 80%, 10 days after inoculation at doses of 1000 and 2000 IJ.larvae-1. The entomopathogenic nematodes are a viable alternative to be considered in the Integrated Pest Management programs of black weevil, in crops such us banana and plantain.

  13. Efficiency of feeding Duddingtonia flagrans chlamydospores to control nematode parasites of first-season grazing goats in France.

    Science.gov (United States)

    Paraud, C; Pors, I; Chartier, C

    2007-04-01

    A field trial, conducted over two consecutive years, was aimed at assessing the efficacy of the administration of spores of the nematophagous fungus Duddingtonia flagrans to young goats for the control of nematode parasite infections on a French commercial dairy goat flock. For both years, the first-year grazing kids were divided into two similarly managed groups (fungus and control groups): in 2003 a daily dose rate of 5 x 10(5) spores/kg body weight was given to the fungus-group animals, while in 2004 a daily dose rate of 10(6) spores/kg body weight was used; the other half of the kids, acting as control, did not receive the spores. Parameters measured every 3 weeks included nematode egg excretion, larval development in faecal cultures and pasture larval counts. Additionally, at the beginning, the middle and the end of each grazing season, the goats were weighed and blood samples for pepsinogen determination were collected. In 2003, similar results were recorded for all the measured parameters in the control and fungus groups. In contrast, in 2004, the kids receiving the spores showed lower faecal egg counts and pepsinogen levels at the end of the season and higher growth rate compared to kids of the control group.

  14. Effect of Sinorhizobium fredii strain Sneb183 on the biological control of soybean cyst nematode in soybean.

    Science.gov (United States)

    Tian, Feng; Wang, Yuanyuan; Zhu, Xiaofeng; Chen, Lijie; Duan, Yuxi

    2014-11-01

    The soybean cyst nematode (SCN; Heterodera glycines) is a major detriment to soybean production. The endophytic bacterium Sinorhizobium fredii strain Sneb183 is known to inhibit the activity of SCN. In the present study, soybean seedlings were inoculated with Sneb183, to study the penetration juveniles, and their development inside the roots. The number of cysts in the soybean roots was also examined. The induced systemic resistance in soybean was also examined through the split-root system. Our results revealed that the number of juveniles and cysts significantly decreased as a result of Sneb183 inoculation. Sneb183 also prolonged the developmental stage of SCN in the root to 30 days as compared to 27 days in the control. Furthermore, the number of nematodes in each stage was lower in the Sneb183 treated plants than control plants. We also used a split-root system to show that the S. fredii strain Sneb183 induced a systemic resistance to SCN infection in soybean. The repression rate of SCN penetration was 38.75%. Our study showed that Sneb183 can be an effective biocontrol agent for managing SCN infestation in soybean.

  15. Caenorhabditis elegans: a simple nematode infection model for Penicillium marneffei.

    Directory of Open Access Journals (Sweden)

    Xiaowen Huang

    Full Text Available Penicillium marneffei, one of the most important thermal dimorphic fungi, is a severe threat to the life of immunocompromised patients. However, the pathogenic mechanisms of P. marneffei remain largely unknown. In this work, we developed a model host by using nematode Caenorhabditis elegans to investigate the virulence of P. marneffei. Using two P. marneffei clinical isolate strains 570 and 486, we revealed that in both liquid and solid media, the ingestion of live P. marneffei was lethal to C. elegans (P<0.001. Meanwhile, our results showed that the strain 570, which can produce red pigment, had stronger pathogenicity in C. elegans than the strain 486, which can't produce red pigment (P<0.001. Microscopy showed the formation of red pigment and hyphae within C. elegans after incubation with P. marneffei for 4 h, which are supposed to be two contributors in nematodes killing. In addition, we used C. elegans as an in vivo model to evaluate different antifungal agents against P. marneffei, and found that antifungal agents including amphotericin B, terbinafine, fluconazole, itraconazole and voriconazole successfully prolonged the survival of nematodesinfected by P. marneffei. Overall, this alternative model host can provide us an easy tool to study the virulence of P. marneffei and screen antifungal agents.

  16. Rogue sperm indicate sexually antagonistic coevolution in nematodes.

    Directory of Open Access Journals (Sweden)

    Ronald E Ellis

    2014-07-01

    Full Text Available Intense reproductive competition often continues long after animals finish mating. In many species, sperm from one male compete with those from others to find and fertilize oocytes. Since this competition occurs inside the female reproductive tract, she often influences the outcome through physical or chemical factors, leading to cryptic female choice. Finally, traits that help males compete with each other are sometimes harmful to females, and female countermeasures may thwart the interests of males, which can lead to an arms race between the sexes known as sexually antagonistic coevolution. New studies from Caenorhabditis nematodes suggest that males compete with each other by producing sperm that migrate aggressively and that these sperm may be more likely to win access to oocytes. However, one byproduct of this competition appears to be an increased probability that these sperm will go astray, invading the ovary, prematurely activating oocytes, and sometimes crossing basement membranes and leaving the gonad altogether. These harmful effects are sometimes observed in crosses between animals of the same species but are most easily detected in interspecies crosses, leading to dramatically lowered fitness, presumably because the competitiveness of the sperm and the associated female countermeasures are not precisely matched. This mismatch is most obvious in crosses involving individuals from androdioecious species (which have both hermaphrodites and males, as predicted by the lower levels of sperm competition these species experience. These results suggest a striking example of sexually antagonistic coevolution and dramatically expand the value of nematodes as a laboratory system for studying postcopulatory interactions.

  17. Anthelmintic activity of Indigofera tinctoria against gastrointestinal nematodes of sheep

    Science.gov (United States)

    Meenakshisundaram, Ambalathaduvar; Harikrishnan, Tirunelveli Jayagopal; Anna, Thavasi

    2016-01-01

    Aim: Gastrointestinal (GI) nematodes are considered as a major constraint for successful sheep production. Control of these parasites heavily relies on the use of chemical anthelmintics. Over the past decades, the development of anthelmintic resistance to various groups of anthelmintics and problem of drug residues in animal products has awakened interest in medicinal plants as an alternative source of anthelmintics. Hence, this study was undertaken to evaluate the anthelmintic efficacy of Indigofera tinctoria by scientifically validated in vitro and in vivo tests approved by the World Association for the Advancement of Veterinary Parasitology. Materials and Methods: In vitro assays such as egg hatch assay for ovicidal and larval migration inhibition and larval development assay for larvicidal properties were used to investigate in vitro effect of extracts on strongyle egg and larvae, respectively. Fecal egg count reduction test was conducted in vivo to evaluate the therapeutic efficacy of the extracts administered orally at dose rates of 125, 250, 500 mg/kg to sheep naturally infected with mixed GI nematodes. Results: Ethanolic extract of I. tinctoria demonstrated significant (pactivity and could replace the chemical anthelmintics used presently. PMID:27051192

  18. Acidic chitinase primes the protective immune response to gastrointestinal nematodes.

    Science.gov (United States)

    Vannella, Kevin M; Ramalingam, Thirumalai R; Hart, Kevin M; de Queiroz Prado, Rafael; Sciurba, Joshua; Barron, Luke; Borthwick, Lee A; Smith, Allen D; Mentink-Kane, Margaret; White, Sandra; Thompson, Robert W; Cheever, Allen W; Bock, Kevin; Moore, Ian; Fitz, Lori J; Urban, Joseph F; Wynn, Thomas A

    2016-05-01

    Acidic mammalian chitinase (AMCase) is known to be induced by allergens and helminths, yet its role in immunity is unclear. Using AMCase-deficient mice, we show that AMCase deficiency reduced the number of group 2 innate lymphoid cells during allergen challenge but was not required for establishment of type 2 inflammation in the lung in response to allergens or helminths. In contrast, AMCase-deficient mice showed a profound defect in type 2 immunity following infection with the chitin-containing gastrointestinal nematodes Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. The impaired immunity was associated with reduced mucus production and decreased intestinal expression of the signature type 2 response genes Il13, Chil3, Retnlb, and Clca1. CD103(+) dendritic cells, which regulate T cell homing, were also reduced in mesenteric lymph nodes of infected AMCase-deficient mice. Thus, AMCase functions as a critical initiator of protective type 2 responses to intestinal nematodes but is largely dispensable for allergic responses in the lung.

  19. Evaluation of Eucalyptus citriodora essential oil on goat gastrointestinal nematodes.

    Science.gov (United States)

    Macedo, Iara Tersia Freitas; Bevilaqua, Claudia Maria Leal; de Oliveira, Lorena Mayana Beserra; Camurça-Vasconcelos, Ana Lourdes Fernandes; Vieira, Luiz da Silva; Amóra, Sthenia Dos Santos Albano

    2011-01-01

    Phytotherapy may be an alternative strategy for controlling gastrointestinal parasites. This study evaluated the anthelmintic efficacy of Eucalyptus citriodora essential oil (EcEO). The in vitro effects of EcEO were determined through testing the inhibition of egg hatching and larval development of Haemonchus contortus. EcEO was subjected to acute toxicity testing on mice, orally and intraperitoneally. The in vivo effects of EcEO were determined by the fecal egg count reduction test (FECRT) in goats infected with gastrointestinal nematodes. The results showed that 5.3 mg.mL(-1) EcEO inhibited egg hatching by 98.8% and 10.6 mg.mL(-1) EcEO inhibited H. contortus larval development by 99.71%. The lethal doses for 50% of the mice were 4153 and 622.8 mg.kg(-1), for acute toxicity orally and intraperitoneally. In the FECRT, the efficacy of EcEO and ivermectin was 66.25 and 79.16% respectively, on goat gastrointestinal nematodes eight days after treatment. EcEO showed in vitro and in vivo anthelmintic activity.

  20. FAMILY OF FLP PEPTIDES IN CAENORHABDITIS ELEGANS AND RELATED NEMATODES

    Directory of Open Access Journals (Sweden)

    Chris eLi

    2014-10-01

    Full Text Available Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system has been identified. The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides. These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FMRFamide-related peptides described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and signaling pathways through which they function.