2017 ASHS Annual Conference

The respiration rate and chemical composition was characterized in the roots of 15 commercially grown U.S. sweetpotato cultivars and advanced breeding lines. Root respiration rate was highest in ‘Porto Rico’ and ‘Evangeline’ and lowest in ‘Bonita’ and ‘Murasaki’. Dry matter content was highest in ‘Murasaki’ and ’13-164’ (~28 %) and lowest in ‘Bellevue’ (18.3 %). Total sugar content was highest in the orange-flesh cultivar ‘Bayou Belle’ ( 9.8 %) and lowest in the purple-flesh breeding line ’13-164’ (4.6 %). Sucrose was the principal sugar in raw roots of all cultivars except ‘Bellevue’ and ‘14-15’, which contained more glucose. Glucose was the secondary sugar in most genotypes, followed by fructose. The orange-flesh cultivars ‘Covington’ and ‘Evangeline’ contained the lowest amounts of monosaccharides. Malic acid was the principal organic acid in all cultivars except the purple-flesh types, in which citric acid dominated. Total carotenoid content was highest in the orange-flesh cultivars ‘Burgundy’ and Evangeline’ and lowest in the cream-flesh cultivars ‘Bonita’ and ‘Murasaki’. Potassium was the principal macronutrient in all cultivars, followed by phosphorus. Iron and manganese were the principal micronutrients in all cultivars, followed by zinc, copper, and boron. Significant differences in chemical composition and nutritional attributes existed between cultivars.