rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: The
    title: retention of maize dwarf mosaic virus by the greenbug, schizaphis graminum rondani and its implications for transmission mechanisms
  name:
    name part: Berger, Philip Hamilton
    role:
      role term: creator
  name:
    name part: Frederiksen, R. A.
    role:
      role term: degree committee member.
  name:
    name part: Halliwell, R. S.
    role:
      role term: degree committee member.
  name:
    name part: Harris, K. F.
    role:
      role term: degree committee member.
  name:
    name part: Thomas, R. E.
    role:
      role term: degree committee member.
  name:
    name part: Toler, R. W.
    role:
      role term: degree supervisor.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1983
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: ix, 76 leaves : illustrations ; 29 cm
  abstract: For over five decades it was thought that aphids transmitted nonpersistent phytopathogenic viruses in what has been termed a "stylet-borne" manner. More recently, it has been proposed that aphids transmit virus as a result of "ingestion and egestion" of virus-containing plant sap. In the former case, virus is acquired and carried as a contaminant in the distal portion of the stylets. Ingestion-egestion, on the other hand, provides that virus is carried up to the maxillary food canal of the alimentary canal and perhaps beyond the pharyngeal gustatory organ. In the latter case there is greater opportunity for interaction between virus and both living and nonliving surfaces within the aphid. When the rate of loss of infectivity of MDMV (maize dwarf mosaic virus) was studied, early results suggested that both ingestion-egestion and stylet-borne contamination were operative mechanisms, the degree to which one predominates depending on the length of the acquisition period. Short acquisition times would result in aphids transmitting virus primarily because of stylet-borne contamination, whereas long acquisition times should result in primarily ingestion-egestion of virus-containing plant sap. Results indicate that the rate of loss of infectivity is independent of acquisition access time. There is a maximal amount of virus that can be acquired by aphids. The hypothesis that a dual-mechanistic approach can explain nonpersistent transmission is not supported. Nonlinear regression analyses can provide good predictions of transmission efficiency after extended retention time intervals. Possible implications of these findings are discussed.
  note: "Major subject: Plant Pathology."
  note: Typescript (photocopy).
  note: Vita.
  note: Ph. D. in Philosophy Texas A & M University 1983
  note: Includes bibliographical references (leaves 61-75).
  subject:
    topic: Aphids as carriers of disease
  subject:
    topic: Plant Pathology
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-578134
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-578134
  record info:
    record content source: TXA
    record creation date: 851107
    record change date: 20220103135214.0
    record identifier: in00000571372
    language of cataloging:
      language term: eng