Ascorbic Acid Content in Spinach: Phenotypic Diversity, Association Mapping, and Effect on Salt Stress Tolerance

Spinach (Spinacia oleracea) is an economically important leafy green crop in the US. Unfortunately, improving nutritional content has not been prioritized in commercial spinach varieties as breeding for yield and disease resistance have been a predominant focus. Vitamin C (ascorbic acid, AsA) is an essential nutrient for humans involved in the growth, development, and repair of tissues. In plants, vitamin C function as an antioxidant that eliminates cell-damaging free radicals produced in response to stress. Previous attempts to enhance AsA in model plants and several crops indicate that increased AsA content results on higher biomass and tolerance to abiotic stresses. Therefore, it is possible to improve nutritional content, yield, and stress tolerance by breeding for vitamin C content. This project is evaluating vitamin C content variability within spinach germplasm, identifying molecular markers associated for their utilization in breeding programs, and evaluating the role of AsA on salt stress tolerance. Preliminary results indicate that natural variation in vitamin C content exists in spinach germplasm making it possible to enhance nutritional density and potentially improve plant stress tolerance using a molecular breeding approach.