Abstract: Tartary buckwheat (Fagopyrum tataricum) products are regarded as health food due to their components of vitamin B1 and E, mineral elements, flavonoids (mainly rutin) and high content of proteins. The composition ratios of eight essential amino acids in tartary buckwheat seeds is similar to that in eggs, and rutin is approved to be effective in protecting humans against chronic diseases (e.g. cardiovascular diseases), heart diseases, and cancer. Selenium (Se) is an essential trace element for higher animals and humans with many physiological functions. To study the effect of Se application on growth, yield and quality of tartary buckwheat, a pot experiment was carried out in 2005. The contents of total Se, amino acid, flavonoids, and rutin were determined by atomic fluorescence spectrophotometer, automatic amino acid analyzer, A UV-VI 8500 spectrophotometer and HPLC respectively. The results showed that appropriate amount of Se (0.5 mg kg^-1 soil) significantly promoted the plant height, dry mat-ter weight of shoots, and the total weight of the plant. With the application of 1.0 mg Se kg^-1 soil, the yield, spikes, and grain number per plant were 1.42–2.32 times and about two times as many as those of untreated plants. The seed setting rate and 100-grain weight were increased by 0.6%–6.2% and 1.90%–5.85% respectively, and the contents of flavonoids and rutin in seeds improved by 3.7%–7.5% and 30.9%–59.6%, respectively. The most effective treatment occurred at the rate of 0.5 mg Se kg^-1 soil, which made the yield, all quality characters of seeds reach the peak. Excessive Se (1.0 mg kg^-1) obviously injured tartary buck-wheat plant, resulting in the decrease of yield, plant height and biomass. Except in the case where the treatment was 0.5 mg Se kg^-1 soil, the contents of N, P, K, Zn, Ca, Mn, crude protein, and fat were increased when the supply of Se was increased. The study showed that the application of Se to soil could significantly increase Se content, meanwhile, decrease starch content to a different extent. It is thus feasible to promote the growth, yield and qualities for nutrition and health care in seeds of tartary buck-wheat by adding appropriate Se to soil.

Key words: Selenium, Tartary buckwheat, Yield, Nutrition quality, Flavoloids, Rutin