大气CO_2浓度和供氮水平对油菜中微量元素吸收及转运的影响

Effect of atmospheric CO_2 concentration and nitrogen application level on absorption and transportation of nutrient elements in oilseed rape

在温室大棚中模拟大气CO2浓度升高(780μmol·mol-1),研究了抽薹期油菜各器官对钙、镁、硫、铁、锰、锌、钼、硼离子吸收与运输的影响.结果表明:与自然CO2浓度(对照)相比,高CO2浓度不施氮条件下,茎的中、微量元素含量除锌增加外,其他均减少,施氮条件(0.2g N·kg-1土)下钙、硫、硼、锌增加,镁、锰、钼、铁减少;叶的中、微量元素两个氮水平下都表现为除钼含量增加外,其他均下降.CO2浓度升高条件下,茎中钙和硫占中量元素总和的比值及硼和锌占微量元素总和的比值增加,镁、铁、锰、钼相应比值减少,两个氮水平下表现一致;CO2浓度升高条件不施氮处理增加了钙在叶中的分配比例,而正常供氮处理则增加了镁的分配比例,两个氮水平下均促进了锰、锌、钼在叶中的分配比例.不施氮条件下,高CO2浓度处理的运输系数SFe,Mo和SS,B高于自然CO2浓度处理,而SMg,Fe、SMg,Mn和SS,Fe低于自然CO2浓度处理,表明CO2浓度升高条件下油菜向上运输的钼和硫高于铁,硼高于硫,镁高于铁和锰;正常供氮条件下,高CO2浓度处理的SMg,Fe、SMg,Mn、SS,B高于自然CO2浓度处理,而SCa,Mg、SFe,Mo、SS,Fe相反,表明CO2浓度升高条件下油菜向上运输的钙、铁和锰高于镁,硼高于硫,铁高于钼,硫高于铁.

Effect of elevated atmospheric-CO2 （780 μmol · mo1-1） on the absorption and transpor- tation of secondary nutrient elements （ calcium, magnesium, sulphur） and micronutrient elements （iron, manganese, zinc, molybdenum and boron） in oilseed rape at the stem elongation stage were studied by greenhouse simulated method. Compared with the ambient CO2 condition, the content of Zn in stem was increased and the contents of other nutrient elements were decreased under the ele- vated atmospheric-CO2 with no nitrogen （N） application ; the contents of Ca, S, B and Zn were in- creased, and the contents of Mg, Mn, Mo and Fe were decreased under the elevated atmospheric- CO2 with N application （0.2 g N · kg-1 soil） ; except the content of Mo in leaf was increased, the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with two levels of N application. Compared with the ambient CO2 condition, the amounts of Ca and S relative to the total amount of secondary nutrient elements in stem and the amounts of B and Zn relative to the total amount of micronutrient elements in stem were increased under the elevated-CO2 treatment with both levels of N application, and the corresponding values of Mg, Fe, Mn and Mo were de- creased; no-N application treatment increased the proportion of Ca distributed into the leaves, and the proportion of Mg distributed into leaves proportions of Mn, Zn and Mo distributed levels. Without N application, the elevation was increased by the normal-N application level; the into the leaves were increased at both N application of atmospheric CO2 increased the transport coefficients of SFe,Mo and SS,B, but decreased the transport coefficients of SMg,Fo, SMg,Mn and Ss,Fe, indicating the proportions of Mo, S transported into the upper part of plant tissues was higher than that of Fe, and the corresponding value of B was higher than that observed for S, the corresponding value of Mg was higher than that of Fe and Mn. Under normal-N application, the elevation of atmospheric CO2 in- creased the transport coefficients of SMg,Fe, SMg,Mn and SS.B, but decreased the transport coefficients of Sca＇ Mg, SFe.Mo and Ss.Fe, indicating the proportions of Fe, Mn and Ca transported into the upper part of plant tissues was higher than that of Mg; the corresponding value of B was higher than that observed for S, the corresponding value of Fe was higher than that of Mo, and the corresponding value of S was higher than that of Fe.