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Roland Perry

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Roland Perry and Richard Rolfe

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Analysis of the contraction and relaxation of pharyngeal musculature derives from measurements of electrical currents, termed electropharyngeograms (EPG). EPG of stylet protractor muscle activity of second stage juveniles (J2) of Globodera rostochiensis, in response to 0.1, 1.0 and 10 mg ml-1 concentrations of the neurotransmitter serotonin, have now been obtained and correlated with stylet protrusion and retraction using video analysis. The antagonist, gramine (10 mg ml-1), incorporated with 10 mg ml-1 serotonin, almost completely eliminated stylet thrusting by J2. Stylet movement can be determined accurately over extended periods with EPG and this approach has potential for investigating factors involved in activation and perturbation of stylet protrusion.

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Roland Perry and David Hunt

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Roland Perry and David Hunt

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Roland Perry and David Hunt

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David Hunt and Roland Perry

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Nematology

International Journal of Fundamental and Applied Nematological Research

Nematology is an international journal for the publication of all aspects of nematological research (with the exception of vertebrate parasitology), from molecular biology to field studies. Papers on nematode parasites of arthropods, and on soil free-living nematodes, and on interactions of these and other organisms, are particularly welcome. Research on fresh water and marine nematodes is also considered when the observations are of more general interest.
Nematology publishes full research papers, short communications, Forum articles (which permit an author to express a view on current or fundamental subjects), perspectives on nematology, and reviews of books and other media.
2017 Impact Factor: 1.12 5 Year Impact Factor: 1.149
Online submission: Articles for publication in Nematology can be submitted online through Editorial Manager, please click here. As of July 1st 2017, full colour images and figures are published free of charge.
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Members of the European Society of Nematologists or Society of Nematologists can subscribe to the 2018 Volume of Nematology at the special individual e-only member subscription rate of EUR 141* / US$ 159. Please send your order to brill@turpin-distribution.com, quoting action code 70258. *excluding VAT.
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Roland Perry, Hari Gaur and Jack Beane

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The root-knot nematode, Meloidogyne triticoryzae, produces three kinds of unhatched second stage juveniles (J2): i) those that hatch freely in water, ii) those that require stimulus from rice root diffusate (RRD), and iii) those that do not hatch even in the presence of RRD. The proportion of these three types varies with generation, with the final generation produced on senescing plants having a large proportion of unhatched J2 of the third type, which is likely to equate with diapause. Dilution of RRD reduced its hatching activity and there is no evidence of the presence of inhibitors in the diffusate. The hatching response of M. triticoryzae may be modified additionally by the growing conditions: submergence of infected plants may have delayed hatch, possibly by causing anoxybiosis in unhatched J2, and thereby delayed the appearance of the second and third generations of the nematodes. Le nématode Meloidogyne triticoryzae produit trois types de juvéniles de 2ème stade (J2) non encore éclos: i) ceux qui éclosent d’eux-même dans l’eau; ii) ceux qui requièrent le stimulus produit par le diffusat radiculaire de riz (RRD); enfin iii) ceux qui n’éclosent pas même en présence de RRD. La proportion de ces trois types varie avec la génération du nématode, la dernière génération, produite sur un hôte sénescent, contenant une grande proportion de J2 non éclos de type 3, ce fait représentant l’équivalent d’une diapause. La dilution du RRD diminue l’éclosion et aucune évidence d’inhibiteurs n’a été relevée dans le diffusat. Chez M. triticoryzae l’éclosion peut de plus être modifiée par les conditions de croissance de l’hôte; ainsi la submersion des plants infestés peut retarder l’éclosion, l’anoxybiose ainsi induite affectant vraisemblablement les J2 non éclos et retardant de ce fait l’apparition des deuxième et troisième générations du nématode.

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Hara Menti, Denis Wright and Roland Perry

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The infectivity of populations of the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis megidis from Greece (GR) and the UK was compared using Galleria mellonella larvae as hosts. Dose-response tests showed that the two Steinernema populations did not differ in their establishment rates but they were more infective than H. megidis UK 211. The temperature range for infectivity was greater than that for development. However, the optimal temperature for infection and development for all populations was 23°C. Infectivity of Steinernema populations was not affected by storage for 12 weeks. However, 12 week-old H. megidis UK 211 infective juveniles (IJ) were less infective than fresh IJ. H. megidis GR showed very low establishment rates at all the doses and temperatures tested, before and after storage. The results are discussed in relation to the nematodes' climatic origin and lipid content. Pouvoir infestant de populations des nématodes entomopathogènes Steinernema feltiae et Heterorhabditis megidis suivant la température, l'âge et le contenu lipidique - Le pouvoir infestant de populations des nématodes entomopathogènes Steinernema feltiae et Heterorhabditis megidis provenant de Grèce et du Royaume Uni a été comparée, utilisant comme hôte Galleria mellonella. Les tests de dose/réaction ont montré que les taux d'établissement des deux populations ne diffèrent pas mais que leur pouvoir infestant était plus élevée que celle de H. megidis UK211. La plage des températures permettant l'infestation était plus étendue que celle relative au développement. Cependant, les températures optimales pour l'infestation et pour le développement étaient l'une et l'autre de 23°C pour toutes les populations. L'infestivité des populations de Steinernema n'a pas été affectée par un stockage de 12 semaines. Les juvéniles infestants de H. megidis UK211 âgés de 12 semaines montraient toutefois une infestivité plus faible que celle d'individus frais. Les specimens de H. megidis provenant de Grèce présentaient - que ce soit avant ou après le stockage - des taux d'établissement très faibles pour toutes les doses et les températures testées. Ces résultats sont discutés en relation avec l'origine climatique et le contenu lipidique des nématodes.