Effects of exogenous Se mineral powder on the accumulation of Se and the absorption of mineral elements in maize

【Objectives】 Bio-augmentation of organic Se through fertilization is an important strategy to increase the Se intake of whole populations. Here the proper dose of Se in crop production was studied to provide the theoretical and technique guidance for Se-enriched agricultural products.【Methods】 Maize was used as experimental materials and Se mineral powder (Se 180 mg/kg) from Enshi City of Hubei Province as the exogenous Se sources, a field experiment was conducted in Shandong Provice. The Se accumulation and transformation, the absorption of main nutrient elements in maize were determined. Five levels of Se mineral power were tested in this experiment as follows: Se 0 (CK), 750 (Se1), 1500 (Se2), 2250 (Se3), 3000 g/hm2 (Se4). The plant samples were collected at the big trumpet period and harvest time of maize. The concentration of total Se in different organs and the total Se, organic and inorganic Se concentrations in maize grains were measured.【Results】 There is no significant effects on maize biomass and grain yield with Se applications, but significant improvement on the Se content in maize grain and the organs. The Se content in maize grain is increased from 14.2 to 350.3 μg/kg with the Se application dose increasing from 0 to 3000 g/hm2. The Se content in root at harvest is higher than at tasselling stage, but the Se content in stems and leaves at harvest is lower than at tasselling stage, except for the treatment of Se 1500 g/hm2. The Se accumulation coefficient in different maize organs is in order of rootleafgrainstem, the transferred coefficient is in order of leafgrainstem. Compared with CK, the organic Se content in grain is significantly increased with the application of Se. The organic Se content is ranged from 12.9 to 302.6 μg/kg, and their proportion in total Se content is ranged of 86.87%-90.84%, there are no significant differences among the Se treatments. The total Se and organic Se in maize grain are both significantly correlated with the total Se in vegetative organs (P≤0.05), and extremely significant with that in root (P≤0.01)in both the tasselling and harvest stage. Exogenous Se significantly restrains the absorption of Na, not on those of K, Ca, Mg and Fe, increases those of Mn, Cu and Zn in certain Se dose.【Conclusions】 The application of exogenous Se mineral powder will not affect the grain and biomass yield of maize. The total Se and organic Se concentration in maize grain could be increased significantly with the Se application, but it does not significantly affect their ratios. Se application could increase the absorption of Mn, Cu and Zn in the grain of maize with certain application does. The Se of 750-1500 g/hm2 can be recommended as the Se mineral powder rates.