Genetics of Seed Coat and Stem Development in Flax (Linum usitatissimum L.)

• Author / Creator

  To, Lai T

• Abstract
  Flax (linseed, Linum usitatissimum L) is cultivated either for its seeds or its stem (bast fiber). With the goal of contributing to development of novel flax germplasm, a forward genetics screen of EMS mutagenized flax (var. CDC Bethune) was conducted to identify seeds with abnormal pigmentation or mucilage. Seeds of 16,764 M4 families were examined visually, with and without staining by Toluidine Blue. A total of 86 putative seed color mutants were identified, with the most common phenotype being yellow seeds. There were 1,975 identified putative mucilage mutants, with a range of phenotypes, including Blue Seed, No Mucilage Released, and Abnormal Mucilage Released. A subset of the seed colors and mucilage phenotypes were tested for heritability. The seed colors were generally heritable, but the mucilage phenotypes appeared to show variable expressivity that is probably highly dependent on the environment. Histological analysis revealed how seed coat anatomy changes affected seed color, but did not explain the mucilage phenotypes tested. The lines have been provided to flax breeders other collaborators for further analysis and potential use in breeding programs.
  GASA (Gibberellic Acid Stimulated in Arabidopsis) genes encode a family of small proteins of unknown biochemical function, whose expression has been correlated with various processes in plants including hormone response, defense, and development. GASA genes have also been reported in our lab to be expressed in developing flax stems. To better characterize the GASA-like gene family in flax, I identified 20 predicted GASA-like genes in the flax whole genome assembly. Using microarray and qRT-PCR analysis, seven of these genes showed differential transcript expression during stem development. I cloned and verified the sequences of these genes. Based on these studies, I was able to define groups of flax GASA-like genes whose expression was well-correlated with stem segments in either the elongation or cell wall deposition stage. These results provide further evidence that specific GASA genes are involved in different processes in flax stem and/or fiber development.

• Subjects / Keywords

  • Flax seed color
  • Flax seed mucilage
  • Flax GASA-like gene

• Graduation date

  Fall 2013

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JS9HK1G

• License

  This thesis is made available by the University of Alberta Libraries 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.