The world’s growing population necessitates an increase in both food production and the nutritional quality of our food. To meet these demands, the cultivation of Chenopodium quinoa, a semi-domesticated food crop from the Andes known for its highly nutritious seeds, could be expanded further into areas currently unavailable for agriculture. Quinoa has a large natural diversity and natural tolerance to adverse environmental conditions, including high salinity levels, making it suitable for cultivation in areas with saline soils or depleted groundwater aquifers. However, to maximize its potential for global expansion, the diversity of quinoa needs to be assessed in trials across different regions and agriculturally important traits for different environmental conditions must be identified for crop improvement. An important outcome of my PhD was the published consensus on quinoa phenotyping of a wide range of quinoa features to facilitate the systematic agronomic, physiological and genetic characterization of quinoa for crop adaptation and improvement. These traits were then assessed for their agronomic importance in arid climates through two seasons of replicated field trials in Saudi Arabia. The field trials had a two factorial treatment structure, with control and salt treatments, allowing the dissection of the diversity of responses of quinoa to soil salinity at the whole plant level using visual scores as well as traits from remote sensing. Our trials assessed for the first time the variability of mature quinoa plants of a large panel of quinoa accessions in the response to salinity. Field heterogeneity played a major role in these field trials. This was addressed through the use of different spatial models, from the most basic model, to complex models, to produce spatially adjusted best linear unbiased estimates. The use of a UAV-derived covariate, fractional vegetation cover, to account for variation in irrigation was also assessed, and found to substantially improve the statistical power to identify SNP – trait associations. The genetic architecture of the most relevant traits was assessed through genome-wide association studies. The insights from this work will inform breeding strategies targeting the development of quinoa varieties for target environments.
| Date of Award | Aug 2023 |
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| Original language | English (US) |
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| Awarding Institution | - Biological, Environmental Sciences and Engineering
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| Supervisor | Mark Tester (Supervisor) |
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