• Login
    View Item 
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Phenotypic examination of variation occurring both among families and among genotypes within a T. repens x (T. ambiguum x T. occidentale) BC₁F₂ hybrid population : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Breeding at Massey University, Palmerston North, New Zealand

    Icon
    View/Open Full Text
    01_front.pdf (147.8Kb)
    02_whole.pdf (974.7Kb)
    Export to EndNote
    Abstract
    Development of white clover cultivars with increased vegetative persistence, particularly in dryland farming systems has been a major goal within breeding programmes, however little useful genetic variation for survival and growth in these environments has been found. Consequently, it has become necessary to look towards white clovers wild relatives as sources of genetic variation. T. repens x (T. ambiguum x T. occidentale) tri-species hybrids have been developed, however, their morphologies have not been evaluated, and little is known about optimal breeding strategies in these populations. An experiment was designed to characterise the magnitude of phenotypic variation for a range of root, shoot, and floral traits, and to ascertain optimal breeding strategies within a T. repens x (T. ambiguum x T. occidentale) BC1F2 hybrid plant population. The experiment was designed such that it could be analysed in two ways; a) Investigated levels of phenotypic variation occurring among hybrid families, compared to representatives of their F1 parents b) Investigated levels of phenotypic variation among individual hybrid genotypes, again compared to representatives of their F1 parents. Analysis (a) found a relative lack of among hybrid family variation. With significant (P<0.05) family variance components for 11 of the 18 traits measured, and generally only occurring between the upper and lower extremes. Repeatability estimates on a family mean basis were low (less than 0.51 for all traits). Analysis (b) found significant (P<0.05) genotypic variance components for all of the traits measured. Repeatability estimates ranged from 0.47-0.88, indicating a relatively high level of genetic determination for the majority of traits. Pattern analysis allowed the identification of hybrid genotypes showing the combined expression of key shoot, and root traits. These genotypes may provide a route to hybrid clover cultivars showing increased vegetative persistence via increased nodal and tap-root size, combined with good dry matter production.
    Date
    2017
    Author
    Slack, Stephen Charles
    Rights
    The Author
    Publisher
    Massey University
    URI
    http://hdl.handle.net/10179/12202
    Collections
    • Theses and Dissertations
    Metadata
    Show full item record

    Copyright © Massey University
    | Contact Us | Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1-beta1
     

     

    Tweets by @Massey_Research
    Information PagesContent PolicyDepositing content to MROCopyright and Access InformationDeposit LicenseDeposit License SummaryTheses FAQFile FormatsDoctoral Thesis Deposit

    Browse

    All of MROCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Copyright © Massey University
    | Contact Us | Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1-beta1