University of SaskatchewanHARVEST
  • Login
  • Submit Your Work
  • About
    • About HARVEST
    • Guidelines
    • Browse
      • All of HARVEST
      • Communities & Collections
      • By Issue Date
      • Authors
      • Titles
      • Subjects
      • This Collection
      • By Issue Date
      • Authors
      • Titles
      • Subjects
    • My Account
      • Login
      JavaScript is disabled for your browser. Some features of this site may not work without it.
      View Item 
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item

      Secondary Dormancy of a Diverse Collection of Annual Brassica napus L. Genotypes and the Relationship with Seed Germination, Vigour and Quality Traits

      Thumbnail
      View/Open
      BROWN-THESIS-2019.pdf (1.643Mb)
      Date
      2019-09-24
      Author
      Brown, Caroline Hannah 1994-
      Type
      Thesis
      Degree Level
      Masters
      Metadata
      Show full item record
      Abstract
      Volunteer canola (Brassica napus L.), defined as canola germinating and emerging after the intended cropping season, is the fourth most occurring weed on the Canadian prairies. The largest contribution of seed into the soil seed bank occurs from pod shatter during maturity and harvest. Gene transfer via pollen flow between different varieties is the major concern with volunteer canola. Gene transfer may result in the stacking of herbicide tolerance types in subsequent volunteer canola populations. Seed dormancy is the physiological mechanism prolonging the presence of viable seed in the soil seed bank. Specifically, canola has a high propensity to be induced into secondary dormancy (SD) under adverse environmental conditions not conducive for germination. Previously screened Canadian commercial material ranged from 0-90% propensity to enter SD. A reduction of SD in modern canola varieties may result in lower seed bank persistence, however, the indirect effect this would have on other seed traits is not known. This study examined a diverse collection of annual B. napus genotypes produced in contrasting maternal environments for SD as well as seed germination, vigour and quality traits. Absolute SD values ranged from 0-77% dormant in the diversity collection screened. Genotype was shown to be the main contributor to the variability in SD observed (50%), the interactions between the genotype and environment had a moderate contribution (30%) and very little contribution from maternal environment alone was observed. Genotypes with low SD were more consistent across maternal environments compared to mid and high SD genotypes. No association was observed between SD and germination time or seed vigour traits in the genotypes examined. A significant positive correlation between SD and total protein content was found (r= 0.34; P < 0.001). Total oil content was negatively correlated to SD (r= -0.24; P < 0.05), likely due to the inverse relationship between oil and protein. From the results in this study, the reduction of SD as a breeding objective in canola breeding programs is feasible as the trait is largely genetically controlled. Likewise, the reduction of SD is unlikely to impact seed germination or vigour traits and SD should not be a large contributor to poor stand establishment of canola.
      Degree
      Master of Science (M.Sc.)
      Department
      Plant Sciences
      Program
      Plant Sciences
      Supervisor
      Shirtliffe, Steve; Vail, Sally
      Committee
      Gulden, Rob; Bett, Kirstin; Feurtado, Allan; Bueckert, Rosalind
      Copyright Date
      November 2019
      URI
      http://hdl.handle.net/10388/12364
      Subject
      canola
      Brassica napus
      volunteer canola
      secondary dormancy
      Collections
      • Graduate Theses and Dissertations
      University of Saskatchewan

      University Library

      © University of Saskatchewan
      Contact Us | Disclaimer | Privacy