Evaluation of candidate orange-fleshed sweetpotato clones for nutritional traits

Abstract

ABSTRACTInformation on the nutrient contents of newly developed orange-fleshed sweetpotato (OFSP) varieties is required for recommendations to growers and the food industry. Therefore, the objectives of this study were to determine the nutritional value of newly developed OFSP clones and to establish the associations between β-carotene content and micro-nutrients for targeted large scale production to alleviate nutrient deficiencies. Seventeen OFSP and eight white/cream-fleshed sweetpotato clones were evaluated across six diverse environments (Halaba, Kokate, Areka, Arbaminch, Hawassa and Dilla) in southern Ethiopia in 2014 using a 5 × 5 simple lattice design. Nutritional traits data were collected on dry-weight basis and subjected to analysis of variance and correlation analyses. Environment, genotype, and genotype × environment interaction effects were highly significant (p < 0.01) for all parameters measured. A newly developed genotype, designated G8, had the highest contents of β-carotene (20.01 mg 100 g−1), protein (7.08%), iron (2.55 mg 100 g−1), zinc (1.42 mg 100 g−1), fructose (4.45%), glucose (5.34%) and sucrose (16.20%). Genotypes G15 and G19 also performed relatively well for the above nutritional traits. The three genotypes, G8, G15 and G19 had mean fresh root yield of 23.5,13.7 and 21.3 tha−1, respectively. These genotypes had root dry matter content of 26.99%, 25.23% and 33.09%, respectively. Β-carotene content had significant positive correlations with iron, zinc, fructose, glucose and sucrose content. This reflects the potential to breed for OFSP varieties enriched with the important micro-nutrients. Overall, the candidate OFSP clones, G8 (Resisto × PIPI-2), G15 (Resisto × Temesgen-23) and G19 (Resisto × Ogansagen-23) were good sources of nutritional traits such as vitamin A, iron, zinc, protein, sucrose, glucose and fructose. The selected genotypes can be recommended for large-scale production, food processing or further sweetpotato improvement to alleviate nutrient deficiencies in Ethiopia or similar environments in sub-Saharan Africa.