The Influence Of Different Selenium Sources On The Growth And Selenium Accumulation Of Wheat And Oil Seed Rape

Through soil culture experiment, it was studied in this paper that the effects of selenium powder, selenium mineral, sodium selenite and sodium selenate on growth and selenium accumulation of wheat and oil seed rape, aiming to evaluate the effects of these four kinds of selenium sources on crops and to provide technical support for the rational use of different selenium sources. The main results were as follows:1Effects of different selenium sources on the growth of wheat and oil seed rapeThere were significant differences in the growth of wheat and oil seed rape under different selenium sources. Selenium powder had no obvious effect on the growth of wheat and oil seed rape. The growth of wheat and oil seed rape was promoted in all test concentrations (2-15mg/kg) under selenium mineral treatment, and wheat yield was increased by1.34to16.30percent, as for oil seed rape yield, it was increased by4.09to12.12percent. Sodium selenate and sodium selenite had the most significant effect on wheat and oil seed rape growth, and the growth of wheat and oil seed rape was promoted at suitable concentration, and wheat yield was increased by7.77to14.58percent, for oil seed rape, the yield was increased by8.29to16.91percent, however, the growth of wheat and oil seed rape was inhibited by sodium selenate and sodium selenite at too high concentration, and wheat yield was decreased by2.19to19.07percent, for oil seed rape, the yield was decreased by2.02percent. For the growth of wheat the optimal concentration of sodium selenite and sodium sodium selenate was both2mg/kg, as for oil seed rape, the best concentration of sodium selenite was15mg/kg, and the best concentration of sodium selenite was2mg/kg. Therefore, crops had higher sensitivity for sodium selenate than for sodium selenite, and oil seed rape was more tolerant to high selenium than wheat.2Effects of different selenium sources on reactive oxygen species metabolism of wheat and oil seed rapeThe results showed that in wheat and oil seed rape leaf, at suitable selenium concentration the activity of antioxidant enzymes such as SOD and POD was enhanced, and the content of active oxygen scavengers such as GSH and AsA was improved, at the same time, the content of membrane lipid peroxidation MDA decreased. However, when the selenium concentration was too high, the activity of antioxidant enzymes such as SOD and POD decreased, and the content of active oxygen scavengers such as GSH and AsA decreased, while the content of MDA increased. So the growth of wheat and oil seed rape had something with active oxygen metabolism.3Effects of different selenium sources on selenium accumulation of wheat and oil seed rapeAbsorptive capacity of selenium in wheat and oil seed rape was different under different selenium sources. Wheat and oil seed rape absorbed little selenium powder, while these two crops had the strongest absorption capacity of sodium selenate, and sodium selenite was the second, and the absorption capacity of selenium mineral was weaker than sodium selenite. The accumulation amount of selenium was432.95-6940.95μg under the treatment of sodium selenate in oil seed rape, which was13-50times of sodium selenite treatment at the same concentration, for selenium mineral it was29-108times. The accumulation amount of selenium was25.94-2540.19μg under the treatment of sodium selenate in wheat, which was28-38times of sodium selenite treatment at the same concentration, for selenium mineral it was7-133times. The absorptive capacity of selenium was higher in oil seed rape than wheat, and the accumulation amount of selenium was3-17times in oil seed rape compared with wheat.Selenium distribution were significant different in different parts of wheat and oil seed rape. Selenium content in the aboveground part of wheat and oil seed rape was higher than root under sodium selenate treatment, on the contrary, selenium content in the aboveground part of wheat and oil seed rape was lower than root under the treatment of selenium mineral and sodium selenite. The seed had39to50percent selenium accumulation amount of the whole aboveground part at wheat mature stage, and for oil seed rape, the proportion was21to29percent.There is obvious difference in wheat and oil seed rape selenium accumulation in different growth stages. From seedling stage to flowering stage in wheat, selenium accumulation amount was the highest, and it was49to85percent of the accumulation amount during whole growth period. Selenium accumulation amount reached the highest level at the bolting to the maturity stage under the treatment of oil seed rape selenium mineral and sodium selenite, and it was61to65percent of the accumulation amount during whole growth period. Selenium accumulation amount reached the highest level at the bolting to the maturity stage under the treatment of sodium selenite, and it was the61percent of the accumulation amount during whole growth period.4Effects of selenium on nutrient absorption of wheat and oil seed rapeEffects of selenium sources on nutrient absorption in wheat and oil seed rape was most significant under sodium selenate treatment. The N, P, K content in all organs and S content in the stem was significantly increased at wheat maturity stage under sodium selenate treatment and the Ca and Mg content (except Ca and Mg content in the stem had a rising trend) was not influenced obviously. The N, S content in all organs and Mg content in grains was increased under sodium selenate treatment at oil seed rape mature stage, but the P, K and Ca content was not affected obviously.