Date of Award
Doctor of Philosophy (PhD)
Plant and Environmental Science
William Bridges, Jr.
Pea (Pisum sativum L.) is an important cool season food legume for sustainable food production and human nutrition due to its nitrogen fixation capabilities and nutrient-dense seed. However, phosphorus (P) can be a major limiting nutrient for pea production, as their nodules require additional amounts of P to perform and maintain nitrogen fixation activity, and for adequate biomass and yield. To determine if genetic variation exists in pea’s ability to take up and remobilize P from the soil, we conducted a greenhouse experiment to collect tissues at two developmental stages from plants grown under a normal and reduce P fertilizer regiment. By analyzing P concentrations across lower leaves, upper leaves, and seeds at pea mid and full maturity using ICP-OES, we were able to determine that genotype plays a significant (p < 0.001) role in P concentration across tissues. Additionally, we observed that some pea accessions were able to better remobilize P from mature to developing tissues under reduced P conditions, meaning these accessions may grow and yield better than other accessions under P deficiencies. Additionally, little genomic research has been conducted for pea in terms of biofortification. Biofortification is the strategy of improving a crop’s nutritional quality through conventional breeding practices to combat hidden hunger, which is a term used to describe micronutrient deficiencies present in a population. Pea is highly nutritious, rich in iron, zinc, prebiotic carbohydrates, and fiber, all of which can positively impact human health through incorporation into the diet. To determine if the development of biofortified pea varieties is possible, we conducted a genome wide association study (GWAS) to identify genomic loci associated with iron, zinc, calcium, phosphorus, potassium, as well as phytic acid, which is an antinutrient that decreases the availability of micronutrients during digestion. We found that calcium exhibits moderate broad-sense heritability estimates, while all other minerals and phytic acid have low heritability estimates, meaning their concentrations are likely influenced by the environment rather than genetic factors. Additionally, we were able to identify several significant genomic loci for iron, zinc, and phosphorus concentration in the seed, as well as identify candidate genes associated with the phenotype. Overall, this work contributes to our understanding of nutritional traits and the future of biofortification and genomic research in pea.
Powers, Sarah, "Evaluating Pea (Pisum sativum L.) for Nutritional Traits and Implications for Organic Agriculture and Biofortification" (2021). All Dissertations. 2899.