The distribution of Longidoroidea (nematoda) in Europe and variation in the morphology, biology and virus transmission of Xiphinema diversicaudatum (Micoletzky, 1927) Thorne, 1939

Brown, Derek John Finlay (1983). The distribution of Longidoroidea (nematoda) in Europe and variation in the morphology, biology and virus transmission of Xiphinema diversicaudatum (Micoletzky, 1927) Thorne, 1939. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0000d647

Abstract

The geographical distributions in European and Mediterraneancountries of 58 species in the Longidoroidea are shown on standardisedfonmat maps. This information and interspecific variability in theLongidoroidea is used to form groups of nematodes each group generallyconsisting of an amphimictic species and several thelytokous species.The possibility is discussed that within each group the thelytokousspecies may have evolved from the ancestral amphimictic species.

An examination of intraspecific variability between populationsof Xiphinema diversicaudatum from Europe, USA and New Zealand revealedmuch! significant variation in their morphometrics and populationscould be grouped according to their morphological similarity. Methodsof killing, fixing and processing specimens to glycerol, themicroscope-measuring system, operator recording measurements andchanges in biotope altered significantly the morphometrics ofX. diversicaudatu. Differences occurred in the proportions of malesand females in populations of the species and, using a standard testsystem, populations were .found to have different reproductivecapacities. However, females from the populations successfullycrossbred with males from a Scottish population and produced viable Fland F2 hybrids which confirmed the populations belonged to the samespecies.

Strains of arabis mosaic and strawberry latent ringspot (SLRV)viruses were transmitted, each with a different degree of efficiency,by populations of X. diversicaudatum and specificity of transmissionexisted between each virus strain and each nematode population.Different virus source and bait- plants affected the efficiency withwhich viruses were transmitted and a strain of SLRV from Italy wastransmitted consistently only by a population from Italy. Infrequentor non-transmission of viruses by nematodes resulted from an inabilityof the nematodes to adsorb and retain virus particles at specificsites. A study using parental and F1 and F2 hybrid X.\diversicaudatumrevealed that the nematodes ability to adsorb and retain virusparticles was hereditary and that different maternal and paternalparents could affect the potency of the hybrids as virus vectors.

Results from this research programme form a basis with which tocompare interspecific variability in the Longidoroidea.

Viewing alternatives

Download history

Metrics

Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions

Item Actions

Export

About