The study investigated the effects of cropping system (CS), mulching (M) and year (Y) on the nutritional profile and colour parameters of four sweet potato varieties, namely Purple Speclet, Martina, Janja and Lučka. The results showed that the variations were mainly due to the genetic makeup of the varieties, with Purple Speclet having the highest dry matter, protein, vitamin C content, total phenolic content, antioxidant potential and total soluble solids. Lučka had the highest total sugar content, while Martina and Janja only stood out in terms of glucose content. The nutritional parameters correlated strongly with the colour parameters, suggesting that colour could be a useful indicator for predicting the nutritional quality of sweet potatoes. Nutritional parameters such as total phenolic content (TPC), vitamin C, antioxidant activity (AOP) and dry matter (DM) were significantly influenced by growing season, cropping system and mulching. The growing season had the greatest influence on TPC, vitamin C, AOP and DM. Mulching had the highest impact on DM, glucose content and vitamin C, while the cropping system had the highest impact on vitamin C, AOP and protein content. In particular, organic farming without PE mulching during the growing season resulted in higher levels of vitamin C, TPC and AOP, especially in relatively less favourable weather conditions. However, when PE mulch was used, there was a significant decrease in TPC and AOP. In contrast, no significant environmental influence was observed for the colour parameters, evidently differentiated in the purple-fleshed genotype with respect to the others, indicating that they are predominantly under strong genetic control. The results could help to introduce nutrient-rich sweet potato varieties into sustainable cropping systems and promote the production of sweet potatoes in Europe, particularly the Slovenian varieties Lučka, Martina and Janja, which have not been widely cultivated to date.

中文翻译：

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不同果色甘薯品种营养成分和颜色参数的变化：种植制度、覆盖和生长季节的影响


该研究调查了种植制度 （CS）、覆盖 （M） 和年份 （Y） 对四种甘薯品种（即 Purple Speclet、Martina、Janja 和 Lučka）的营养成分和颜色参数的影响。结果表明，差异主要由品种的基因组成引起，其中 Purple Speclet 的干物质、蛋白质、维生素 C 含量、总酚含量、抗氧化潜力和总可溶性固形物含量最高。Lučka 的总糖含量最高，而 Martina 和 Janja 仅在葡萄糖含量方面脱颖而出。营养参数与颜色参数密切相关，表明颜色可能是预测红薯营养质量的有用指标。总酚含量 （TPC） 、维生素 C、抗氧化活性 （AOP） 和干物质 （DM） 等营养参数受生长季节、种植系统和覆盖的显著影响。生长季对 TPC 、 维生素 C 、 AOP 和 DM 的影响最大，覆盖对 DM 、葡萄糖含量和维生素 C 的影响最大，而种植制度对维生素 C 、 AOP 和蛋白质含量的影响最大。特别是，在生长季节没有 PE 覆盖物的有机农业导致维生素 C、TPC 和 AOP 水平更高，尤其是在相对不利的天气条件下。然而，当使用 PE 覆盖物时，TPC 和 AOP 显着降低。相比之下，没有观察到颜色参数的显着环境影响，紫肉基因型相对于其他基因型明显不同，表明它们主要受到强大的遗传控制。 研究结果可能有助于将营养丰富的甘薯品种引入可持续种植系统，并促进欧洲甘薯的生产，特别是斯洛文尼亚的 Lučka、Martina 和 Janja 品种，这些品种迄今尚未得到广泛种植。