Genetic differentiation of Slovenian sweet potato varieties (Ipomoea batatas) and effect of different growing media on their agronomic and nutritional traits

Abstract

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 single sequence repeats 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 genetic relationships. 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 gallic acid equivalent 100 g -1 fresh weight, 0.18 to 0.56 mg Trolox equivalents g -1 FW and 13.7 to 23.5 mg 100 g -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. IntroductionSweet potato (Ipomoea batatas L.; Convolvulaceae) is ranking as the world's 7 th major food crop, which serves as an energy and phytochemical source of nutrition in more than 100 countries (FAOSTAT, 2017;Shekhar et al., 2015). The origin of sweet potato is Central America, but at present it is widely cultivated in the tropics and subtropics, and even in some temperate areas at different ecological regions (Chandrasekara and Kumar, 2016). In Europe, where the total production of sweet potato accounted 45.901 t in 2014, the biggest producers are Portugal (22.591 t), Spain (13.550 t), Italy (6723 t) and Greece (3038 t) (FAOSTAT, 2017). In Slovenia, sweet potato has been quite unknown crop until recently, both for production and human consumption. The environment diversity and specific climatic conditions of this region could enable successful production of that crop in the future (Kunstelj et al., 2013(Kunstelj et al., , 2015. Three new Slovenian sweet potato varieties (Lučka, Janja, Martina) were registered in 2015 and are now added to national list of varieties (National list of Varieties, 2016).Tubers of sweet potato are rich in dietary fibre, minerals, vitamins and antioxidants, such as phenolic compounds (Lebot et al., 2016;Tang et al., 2015;Teow et al., 2007). Besides acting as antioxidants, phenolic compounds and carotenoids also provide sweet...

Processing methods affect phytochemical contents in products prepared from orange‐fleshed sweetpotato leaves and roots

“…The levels of vitamin C in raw roots in our study were higher than a range of 13.7-23.5 mg/100 g reported in Slovenia (Sinkovič et al, 2017) but comparable to values reported in Tanzania of 273-303 mg/100 g for sweetpotato leaves (Mwanri et al, 2011).Vitamin C is highly susceptible to oxidation more so in aqueous solutions, oxidation being fueled by the presence of oxygen, metal ions such as iron and copper and high temperature (Akah & Onweluzo, 2014;Lee & Kader, 2000). Traditionally, leaves are boiled in water for more than 10 min.…”

Genetic diversity of Lathyrus sativus L. collection and characteristics of seeds produced in Slovenia and Serbia

“…SSR (Simple Sequence Repeats) markers can potentially make a significant contribution to the genomics enabled improvement of grass pea. Compared to other agronomically important plant species, SSR markers are the most frequently employed to assess intra-and inter-specific genetic diversity and its genetic structure (Pipan and Meglič, 2019;Pipan et al, 2018;Sinkovič et al, 2017).…”