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: Breeding for Tolerance of Cowpea to Low Phosphorus Soil Conditions through Physiological and Genetic Studies
  name:
    name part: Rothe, Julie Christine
    role:
      role term: creator
    role:
      role term: author.
  name:
    name part: Hays, Dirk B.
    role:
      role term: thesis advisor.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2015
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: Cowpea (Vigna unguiculata (L.) Walp.) is a major food legume across Sub-Saharan West Africa where its leaves, pods and seeds are consumed as food and its residues are fed to livestock as protein rich fodder. However, soils of West Africa are poor in phosphorus (P), a soil macronutrient all crops need for growth. Fertilizer with P is not readily available and is too expensive for West African farmers. This research was therefore, undertaken to identify cowpea lines that inherently grow well in P-deficient soils and use them to breed improved cowpea varieties that require less phosphorus fertilization. A hydroponic phenotypic screening method with silica sand was used to identify cowpea varieties that have tolerance to low soil P as measured by shoot dry biomass production. Both tolerant and susceptible varieties from the screen were further analyzed for root biomass, internal shoot P content, and internal root P content. Seed P, particularly the effect of cotyledon P, and total root production were investigated as physiological sources of tolerance. Tolerant cowpea varieties were crossed with susceptible varieties, and the resulting F₁, F₂ and BC₁ seeds were screened to determine the inheritance and genetic control of tolerance. A Recombinant Inbred Line (RIL) population of a tolerant by susceptible cross was mapped using SSR markers to identify linkage groups or QTL for tolerance to low soil P. Phenotypic screening results identified four cowpea varieties to have P-deficiency tolerance (Big John, IT97K-1069-6, IT98K-476-8, and TX2028-1-3-1) and three cowpea varieties (Big John, CB-46, and Golden Eye Cream) to have partial P-deficiency tolerance via high seed P content. All varieties experienced increases in root production under low P treatments relative to normal P treatments. Phenotyping of F₁, F₂, and BC₁ populations showed that low P tolerance is a heritable trait in cowpea with significant additive effects and narrow-sense heritability. Estimates of gene number…
  note: by Julie Christine Rothe.
  note: "Major Subject: Plant Breeding"
  note: Includes vita.
  note: Doctor of Philosophy Texas A & M University 2014 http://hdl.handle.net/1969.1/152599
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major Plant Breeding
  subject:
    topic: Cowpea
  subject:
    topic: Phosphorus deficiency
  identifier: http://hdl.handle.net/1969.1/152599
  record info:
    record content source: TXA
    record creation date: 150203
    record change date: 20151206125637.0
    record identifier: in00003500009
    language of cataloging:
      language term: eng