Graduate Program

Biological Sciences

Degree Name

Master of Science (MS)

Semester of Degree Completion

Fall 2025

Thesis Director

Thomas Canam

Thesis Committee Member

Gary A. Bulla

Thesis Committee Member

Barbara S. Carlsward

Abstract

In addition to their value as prized ornamentals, sunflowers are important crop species due to the nutritional value and high oil content of the seeds. Sunflower oil is a significant contributor to global seed oil production, which can be used as a food additive and cooking agent as well as a raw material for biodiesel production. While traditional breeding efforts have led to the development of many unique cultivars, genetically modified variations have proven more difficult due to the recalcitrance of sunflower plants to genetic transformation. As a result, facile and efficient transformation methods for sunflowers have the potential to significantly improve sunflower growth and production. In the present study, the overall strategy was to further optimize the transformation efficiency of the Peredovik sunflower variety. As part of this process, a library of Agrobacterium-based binary plasmids containing reporter genes were created using GreenGate cloning technology, which included genes conferring resistance to a variety of selection agents. The innate resistance to sunflower seeds as well as hypocotyl explants was explored, with hygromycin (10 µg/ml), phosphinothricin (20 µg/ml), and D-alanine (500 µg/ml) preventing both seed germination and callus development in hypocotyl explants, suggesting that plasmids conferring resistance to these toxins are favorable for transformation efforts. The effects of hormone concentrations on seed germination as well as explant health and productivity were also explored. The presence of 6-benzylaminopurine (BAP) and naphthaleneacetic acid (NAA) generally led to stunted development of germinated Peredovik plants in tissue culture, while unique combinations of BAP and NAA in solid or liquid media led to desirable callus formation in hypocotyl and cotyledon explants. Overall, the data obtained from these experiments should help optimize future sunflower transformation strategies aimed at improving the traits and characteristics of this important crop species.

Download

Share

COinS