Generation of Genetic Material to Evaluate Arbuscular Mycorrhizal Symbiosis in Maize
Open Access
- Author:
- Nguyen, Liza
- Graduate Program:
- Horticulture
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 22, 2021
- Committee Members:
- Ruairidh James Hay Sawers, Thesis Advisor/Co-Advisor
Liana T Burghardt, Committee Member
Jesse R Lasky, Committee Member
Erin L Connolly, Program Head/Chair - Keywords:
- mapping population
D14
D14L
landrace
mycorrhizae
arbuscular mycorrhizal colonization
roots
castor
pollux - Abstract:
- The domestication of food crops has revolutionized society by fostering the development of large-scale agriculture. Maize (Zea mays) is a highly important domesticated crop grown globally which feeds millions of people. Demand for maize production as human populations grow in conjunction with climate change has put immense pressure on increasing maize yield. At the same time, increasing desire for sustainable agriculture is driving agricultural practices to require less inputs such as fertilizer and pesticides. Understanding maize’s interactions with beneficial arbuscular mycorrhizal fungi and other microbiota can improve the crop’s hardiness to environmental stressors while reducing the need for such inputs. In my thesis, I design and initiate the development of mapping populations to reveal the influence of mycorrhizae in maize cultivation. This work will provide important information to understand how current agricultural systems interact with mycorrhizae while allowing for better integration of fungal communities into agricultural practice. These mapping populations will enable mapping of QTL linked to increased maize response to mycorrhizae, which may be used in breeding programs. These mapping populations employ single gene mutations to generate mycorrhizae-free plants in the field, providing a ‘built-in’ non-mycorrhizal control for the evaluation of mycorrhizae response. To facilitate population development, I have optimized KASP SNP markers to follow mycorrhizal mutants. In the second part of my work, I performed a reverse-genetic screen to identify novel mutants in genes associated with maize strigolactone signaling. Uniquely in maize, the gene encoding the strigolactone receptor, Dwarf14, is duplicated, raising intriguing questions about the role of this gene compared to other cereal species. Addressing biological questions about mycorrhizal dynamics in maize will provide insight that can be leveraged to improve maize resilience to environmental stress.