Study on the Transfer and Enrichment Regulation of Different Varieties of Sweet Potato to the Heavy Metal Cadmium in Soil

In this study, in order to explore the accumulation and migration characteristics of sweet potatoto the heavy metal cadmium(Cd)in soil. Using the plot experiment with the five varieties of sweet potato (Guang 87,Jinshan 57,Sushu 16,Pushu 32,Fushu 18 )as the test crops,in order to study the transfer and enrichment regulation of five varieties of sweet potato under the soil enviroments with different Cd content. The results showed that the cadmium content in the organs of harvested sweet potato increased with the increase of cadmium content in the test field, and in the test field with the highest cadmium content, the cadmium content in the root, stem, leaf, skin and flesh of sweet potato was 0.308 0, 0.182 5, 0.019 5, 0.082 9 and 0.052 7 mg·kg^-1, respectively. The cadmium content in the flesh of all varieties of sweet potato met the standard stipulated in the national standard " National Food Safety Standard-limit of Pollutants in Food" (<0.1 mg·kg^-1). The enrichment coefficient of cadmium in the fresh organs of different sweet potato varieties was significantly different, and the average enrichment coefficient of cadmium was the highest in the roots (0.913 mg·kg^-1), followed by the stems (0.413 mg·kg^-1), potato skins (0.311 mg·kg^-1), leaves (0.234 mg·kg^-1), and potato flesh (0.178 mg·kg^-1). Among them, the enrichment coefficient of cadmium in all organs except leaves of Guang 87 was higher than that of other varieties, while the enrichment coefficient of cadmium in the organs of Sushu 16 was the lowest. The enrichment coefficient of cadmium in different organs of all varieties of sweet potato showed in the order of root > stem > potato skin > leaf > potato flesh.