Study of the C genome QTL affecting flowering time in spring oilseed Brassica napus under a short-day condition

• Author / Creator

  Nupur, Juthy Abedin

• Brassica napus, mostly known as canola, is an important oilseed crop in Canada. Earliness
  of flowering and maturity are one of the important traits for growing spring canola in North
  America. These traits can be improved through identification of the genes and alleles affecting
  flowering time and understanding their effect on other traits. In this study, near-isogenic lines
  (NILs) carrying flowering time QTL alleles of Brassica oleracea or B. napus which located on C1
  or C9 chromosome were evaluated under 10 hr photoperiod condition for morphological and root
  and shoot biomass traits to understand the effect of these QTL alleles on the other traits. The NILs
  carrying C1 or C9 allele of B. oleracea flowered earlier, as expected, and no visible difference was
  observed between the NILs and the recurrent parent for leaf characteristics. However, the NILs
  showed significant difference for plant height, shoot and root biomass indicating that the flowering
  time QTL alleles may exert pleiotropic effect on these traits or QTL affecting these traits are
  located in the same genomic region. This thesis research also included expression analysis of
  putative flowering time genes from C5 and C9 flowering time QTL. For this, a set of early- and
  late-flowering B. napus lines developed from a B. napus × B. oleracea interspecific cross were
  used, and expression analysis of 30 flowering genes from C5 (15) and C9 (15) QTL was carried
  out on leaf and shoot apex tissue collected from the plants grown under 10 hr photoperiod
  condition. A majority of the genes showed a greater expression at night than in morning, and
  significant differential expression was observed for CO, PHYA, FT, AP2, SOC1 and TEM1; this
  suggests that these genes might be involved in flowering time variation between the early and late
  flowering lines. The leaf materials of the above-mentioned early- and late-flowering plants were
  also used in a proteomic study to identify the proteins involved in flowering time variation. This
  study identified the proteins involved in photosynthesis, pigmentation, phytohormone signaling,
  stress response, ROS, ion binding, mRNA binding, protein binding and many others. Thus, this
  thesis research showed that the flowering time alleles can exert effect on other morphological and
  physiological traits, and the research also identified the genes and proteins potentially involved in
  the regulation of flowering time in canola under short-day photoperiod conditions.

• Subjects / Keywords

  • Brassica napus
  • photoperiod
  • flowering time
  • proteomics

• Graduation date

  Fall 2024

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-7wj9-fc02

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.