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:
    title: Fitness and competitive interactions of genetically modified strains of Trichoderma virens
  name:
    name part: Weaver, Mark A.
    role:
      role term: creator
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: xx
    date issued: 2001
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: ix, 106 leaves : illustrations ; 28 cm.
  abstract: If genetically engineered biocontrol organisms are to have utility in the agroecosystem they must establish populations in niches occupied by indigenous mircroflora. It may become necessary for purposes of risk management to model the population dynamics of these organisms. I examined the growth of a wild-type strain of Trichoderma virens from alginate prills in agricultural soil in response to increasing levels of inoculum. The per capita growth did not decline with increased inoculum levels, in contradiction to predictions of the Verhulst-Pearl model. To explore these mechanisms of population regulation I investigated the population response to inoculum density in vitro. I observed that on nutrient-rich media, the growth was density dependent, as predicted by the classical ecology models. In contrast, the per capita growth on minimal media, as in soil, did not respond to inoculum levels. In the case of one minimal medium, density dependent per capita growth could be produced by the addition of sugar, supporting the hypothesis that the observations in soil were due to the oligotrophic nature of the medium. Because indirect, resource-mediated, competition is only practically studied in environments with density dependent per capita growth, I developed two, independent in vitro approaches for assessing the fitness and competitiveness of transgenic strains of T. virens. Results from the first method, an adaptation of the de Wit replacement series, suggested that one transgenic strain was less fit than the wild-type, parental strain, but more competitive. The system was validated by experiments between a wild-type strain and a near-isogenic, auxotropic mutant which were found to be similarly fit and competitive. Another experimental approach confirmed the conclusions that the transgenic strain is less fit, but more competitive than the parental strain. Through a statistical approach it was demonstrated that the fitness of a transgenic strain is not predictable on the b…
  note: by Mark A. Weaver.
  note: Vita.
  note: "Major Subject: Plant Pathology".
  note: Issued also on microfiche from University Microfilm Inc.
  note: Ph. D. Texas A&M University 2001.
  note: Includes bibliographical references (leaves 85-105).
  subject:
    topic: Major plant pathology
  identifier: 30-33897 UMI
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 020927
    record change date: 20190325103329.0
    record identifier: in00001700486