Dissertation
NOVEL HERBICIDE RESISTANCE TRAIT INVESTIGATION AND QTL MAPPING IN WHEAT
Doctor of Philosophy (PhD), Washington State University
01/2019
Handle:
https://hdl.handle.net/2376/111326
Abstract
Wheat (Triticum aestivum L.) is among the most important field crops worldwide, particularly in eastern Washington. As one of top economically and calorically important crops, ideal yield potential in opposition to limiting factors such as weed pressure must be maintained. Resistance to indaziflam and clethodim represent novel wheat herbicide mode of actions, fortifying weed management. Novel wheat herbicide resistance traits were identified from 2012 field screens. A soil assay for the evaluation of indaziflam residual effects was developed. The soil assay was used to evaluate fine differences in indaziflam resistance among the most resistant and susceptible lines from the 2012 screen. Concurrently, the evaluation of the phenotypic response associated with a clethodim resistance trait in spring wheat was conducted and compared to the clethodim susceptibility of downy brome. Greater clethodim resistance is needed to avoid crop injury while controlling downy brome. Biparental F2 mapping populations were evaluated for their average response to clethodim. SWP6 and SWP4 fit a monogenic recessive gene action model. QTL analysis of the clethodim resistance trait in the F6 of SWP6 detected 25 unique QTL, indicating the trait is quantitative. Directed sequencing of an ACCase gene segment, the clethodim target site, did not find evidence of clethodim resistance conferring SNPs identified in the literature. To support eventual registration of indaziflam in wheat, field trials for crop injury/weed control were conducted in the dryland winter wheat - summer fallow rotation with indaziflam applied post emergence alone and with pyroxsulam. In the first year, indaziflam plus pyroxsulam provided significantly better control than indaziflam alone. In the second year fallow, high rates of both treatments provided good control, such that only one weed control application was needed, reduced from the typical three or more needed for moisture conservation. Both resistance traits are viable options for incorporation into a wheat trait development program.
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Details
- Title
- NOVEL HERBICIDE RESISTANCE TRAIT INVESTIGATION AND QTL MAPPING IN WHEAT
- Creators
- Tara Leigh Burke Lewis
- Contributors
- Arron H Carter (Advisor)Ian C Burke (Advisor)Karen A Sanquinet (Committee Member)Kimberly A Garland-Campbell (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 176
- Identifiers
- 99900581616701842
- Language
- English
- Resource Type
- Dissertation