The objectives of the present study were firstly to analyse the genetic relatedness among three Slovenian sweet potato varieties; and secondly to assess the effects of different growing media on selected agronomic and nutritional traits of these varieties. Tubers of three varieties ('Lučka', 'Janja', 'Martina') with different skin/flesh colour were produced in planters under glasshouse conditions in five different growing media (perlite, peat, expanded clay, vermiculite, garden soil) from prior raised seedlings. Genetic analysis was performed using a set of eight SSR markers. According to Nei’s genetic distance and pairwise population Fst analysis, the most related varieties are 'Janja' and 'Martina'; in contrast, 'Lučka' and 'Martina' show the weakest geneticrelationships. The following agronomic traits were evaluated: vine length, thickness of vine-base, number of branches, weight of above ground part, number of leaves plant-1, number of tubers plant-1 and tubers weight plant-1. Between nutritional traits total phenolic content (TPC), antioxidant potential (AOP) and ascorbic acid content (AA) were determined in the range: 36.2 to 65.1 mg GAE 100g-1 FW, 0.18 to 0.56 mg TE g-1 FW and 13.7 to 23.5 mg 100g-1 FW, respectively. Significant interactions of growing media (factor A) × variety (factor B) were observed for thickness of vine-base, weight of above ground part, AOP, TPC and AA. Overall, results showed variation in varieties response to growing media. Growing media provide a discriminant classification of the sweet potato varieties according to their agronomic and nutritional traits.
Growing media; genetic analysis; Ipomoea batatas; phenolic compounds