Texas A&M University LibrariesTexas A&M University LibrariesTexas A&M University Libraries
    • Help
    • Login
    OAKTrust
    View Item 
    •   OAKTrust Home
    • Colleges and Schools
    • Office of Graduate and Professional Studies
    • Electronic Theses, Dissertations, and Records of Study (2002– )
    • View Item
    •   OAKTrust Home
    • Colleges and Schools
    • Office of Graduate and Professional Studies
    • Electronic Theses, Dissertations, and Records of Study (2002– )
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Molecular Basis of Heterosis in Maize: Genetic Correlation and 3-Dimensional Network Between Gene Expression and Grain Yield Trait Heterosis

    Thumbnail
    View/Open
    ZHI-THESIS.pdf (7.543Mb)
    Date
    2012-02-14
    Author
    Zhi, Hui
    Metadata
    Show full item record
    Abstract
    Heterosis, or hybrid vigor, refers to the superiority of F₁hybrid performance over the mean of its parents (mid-parent heterosis) theoretically, or the performance of better parents. It has been discovered in many species of plants and animals as well as in humans, and played an important role in enhanced agricultural production, especially in maize, rice and sorghum although the mechanism have not been elucidated. We studied the molecular basis of heterosis with a combined genomics and systems biology approach using model organism maize. We profiled the expression of 39 genes that were most differentially expressed (DG) between the mid-parents and their F1 hybrid (Mo17 x B73) in the 13V-satged, developed whole ear shoots of 13 inbred lines and their 22 F1 hybrids grown in the field trails and phenotyped their 13 traits significant for grain yield. The results showed that gene expression varies significantly among inbreds, among hybrids and in heterosis. The gene clustering heat map and gene action networks in inbreds and hybrids were constructed respectively based on their gene expression profile. According to these pattern analyses, we find dramatically difference between inbreds and their hybrids, although the differential expression varies across different hybrids. Our results also suggest that gene networks are altered from inbreds to hybrids, including their gene contents and wire structures. Last but not least, we have determined the genetic variation correlations between the gene expression and trait performance and constructed the gene networks for the development of 12 of the 13 traits that varied significantly among genotypes. This has led to identification of genes significantly contributing to the performances of the traits, with 1 – 16 genes per trait. These results have indicated that heterosis results not only from altered expression level of corresponding genes between inbreds and their hybrids, importantly, also from the altered gene action networks and expression patterns. These alternations could be derived from gene actions in a manner of additivity, dominance, over dominance, pseudo-overdominance, epistasis and/or their combinations. Therefore, our findings provide a better understanding of the underlying molecular basis of heterosis. The genes identified for the traits will provide tools for advanced studies of the trait heterosis and could be used as tools for their heterosis breeding in maize. The strategy developed in this study will provide an effective tool for studies of other complicated, quantitative traits in maize and other species.
    URI
    http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8766
    Subject
    Heterosis
    Gene Expression Variation
    Gene Network
    Gene and Trait Network
    Phenotype
    Maize
    Hybrid Vigor
    Correlation
    Collections
    • Electronic Theses, Dissertations, and Records of Study (2002– )
    Citation
    Zhi, Hui (2010). Molecular Basis of Heterosis in Maize: Genetic Correlation and 3-Dimensional Network Between Gene Expression and Grain Yield Trait Heterosis. Master's thesis, Texas A&M University. Available electronically from http : / /hdl .handle .net /1969 .1 /ETD -TAMU -2010 -12 -8766.

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Advanced Search

    Browse

    All of OAKTrustCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsDepartmentThis CollectionBy Issue DateAuthorsTitlesSubjectsDepartment

    My Account

    LoginRegister

    Statistics

    View Usage Statistics
    Help and Documentation

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV