There is little data about possible interactions between Se and I in plants. Seeds of common buckwheat and pumkins were soaked in solutions: 10 mgSe/l in the form of selenite or selenate, and 1000mgI/l in the form of iodide or iodate and their combinations. There was little effect of different treatments on potential photochemical efficiency of photosystem II (PSII) in common buckwheat sprouts. In pumpkin sprouts neither of treatment affected the amount of photosynthetic pigments, as well as potential photochemical efficiency of (PSII), which is around 0.8.
In field experiments, tartary buckwheat and hybrid buckwheat were foliarly sprayed with an aqueous solution of sodium selenate (20 mg Se L-1). In treated plants, the selenium content was significantly higher than in controls irrespective of the plant part and taxon of buckwheat. The highest average Se concentrations in hybrid and tartary buckwheat were found in seeds. The main Se species found in seeds was Se-methionine. Selenium sprayed plants had higher photochemical efficiency of photosystem II in both taxa and higher electron transport system activity in hybrid buckwheat suggesting a positive effect of Se on physiological characteristics. Regarding the concentration of Se in both buckwheat taxa and selenomethionine as the dominant species of Se, Se-enriched buckwheat is a potential source of dietary Se for animals and humans.
Tartary buckwheat (Fagopyrum tataricum) is a semiwild plant grown in the Himalaya region. Due to its high concentration of flavonoids and trace elements it is of interest for cultivation in other countries as well. The feasibility of increasing the concentration of Se in grain and in green parts of Tartary buckwheat has not yet been investigated. The aim of this investigation was thus to determine the concentration of Se in different edible parts of Tartary buckwheat treated with different concentrations of Na selenate using different techniques. In plants grown in soil fertilized once with 0.5 and 10 mg Se L−1, Se was efficiently translocated from the roots to the leaves and seeds. Foliar spraying with 0.5 mg Se L−1 increased Se content in leaves and seeds. Among the edible parts of Tartary buckwheat plants the highest content of Se in control and in treated groups was found in leaves, followed by seeds and stems. Regarding recommended Se concentration, edible parts of Tartary buckwheat were safe for human consumption. Soil fertilization with 0.5 and 10 mg Se L−1 and foliar fertilization with 0.5 mg Se L−1 are applicable for cultivation of Tartary buckwheat as a functional food enriched with Se.